CA1136697A - Commutatorless direct current motor drive system - Google Patents
Commutatorless direct current motor drive systemInfo
- Publication number
- CA1136697A CA1136697A CA000344905A CA344905A CA1136697A CA 1136697 A CA1136697 A CA 1136697A CA 000344905 A CA000344905 A CA 000344905A CA 344905 A CA344905 A CA 344905A CA 1136697 A CA1136697 A CA 1136697A
- Authority
- CA
- Canada
- Prior art keywords
- stator phase
- stator
- potential
- phase winding
- induced
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
- H02P6/20—Arrangements for starting
- H02P6/21—Open loop start
Abstract
COMMUTATORLESS DIRECT CURRENT MOTOR DRIVE SYSTEM
Abstract of the Disclosure A commutatorless direct current motor drive system that initiates rotation of a permanent magnet rotor from standstill upon the application of supply potential and then sustains rotor rotation by sequen-tially energizing the polyphase stator phase windings in response to the alternating current potential waveforms induced in the stator phase windings by the magnetic field of the permanent magnet rotor upon rotor rotation.
Abstract of the Disclosure A commutatorless direct current motor drive system that initiates rotation of a permanent magnet rotor from standstill upon the application of supply potential and then sustains rotor rotation by sequen-tially energizing the polyphase stator phase windings in response to the alternating current potential waveforms induced in the stator phase windings by the magnetic field of the permanent magnet rotor upon rotor rotation.
Description
113~ ?7 COMMUTATORLESS DIRECT CURRE~T MOTOR DRIVE SYSTEM
This invention is directed to a drive ~ystem for commutatorless direct current motors of the type having a permanent magnet rotor and polyphase stator phase windings and, more specifically, to a drive system of this type that initiates permanent magnet rotor rotation from standstill upon the appli-~ation of supply potential and ~u~tains rotor rotation by sequential energization of the polyphase stator phase winding~ in response to the phase displaced alternating current potential waveforms induced in the stator phase windings upon rotor rotation.
Commutatorless direct current electric motors are well known in the art. Typically, these lS motors have a permanent magnet rotor t~at is magnet-ized with alternate magnetic poles across the rotor diameter and a polyphase stator having a plurality of phase winding~ that may be individually energized by ~, an applied supply potential source. To sustain rotor rotation, the stator phase windings are se~uentially energized to produce a rotating magnetic field.
Motors of this type, therefore, require a method for determining rotor position so that the individual stator phase windings may be se~usntially energized at the proper time relative to rotor position.
Typically, optical devices, Hall effect devic2s or high frequency energized transformers are employed to *
11366C~7 detect rotor position and produce switch signals at the proper rotor positions to sequentially energize the stator phase windings in a manner to sustain rotor rotation. ~s these rotor position sensing devices require provision~ for mounting them on the motor and present maintenance problems, a commutatorless direct current motor drive system that does not require rotor position sensing devices is desirable.
It is, therefore, an object of this invention to provide an improved commutatorless direct current motor drive system.
It i9 another object of this invention to provide an improved commutatorless direct current motor drive system that is capable of initiating rotor rotation from standstill upon the application of supply potential and sustaining rotor rotation after start.
It is an additional object of this invention , to provide an improved commutatorless direct current motor drive system that provides for the sequential energization of the phase windings of a polyphase stator in response to the phase displaced alternating current potential waveforms induced in the stator phase windings by the magnetic field of the permanent magnet rotor upon rotor rotation.
In accordance with this invention, a commutatorless direct current motor drive system is 113~697 provided wherein the polyphase stator phase windings of the motor are individually energized in sequence by an applied supply potential source in response to the phase displaced alternating current potential waveforms induced in the stator phase windings by the magnetic field produced by a permanent magnet rotor upon rotor rotation.
For a better understanding of the present invention, together with additional objects, advan-tages and features thereof, reference is made to thefollowing description and acco~npanying drawing in which: .
Figure 1 sets forth the commutatorless direct current motor drive sy~tem of this invention in schematic form, and Figure 2 is a set of curves useful in understanding the operation of the circuit of Figure 1.
As point o reference or ground potential is the same point electrically throughout the system, it is illustrated in Figure 1 by the accepted schematic symbol and referenced by the numeral 5.
The supply potential source may be a con-ventional storage battery 3 or any other suitable direct current potential source having current and
This invention is directed to a drive ~ystem for commutatorless direct current motors of the type having a permanent magnet rotor and polyphase stator phase windings and, more specifically, to a drive system of this type that initiates permanent magnet rotor rotation from standstill upon the appli-~ation of supply potential and ~u~tains rotor rotation by sequential energization of the polyphase stator phase winding~ in response to the phase displaced alternating current potential waveforms induced in the stator phase windings upon rotor rotation.
Commutatorless direct current electric motors are well known in the art. Typically, these lS motors have a permanent magnet rotor t~at is magnet-ized with alternate magnetic poles across the rotor diameter and a polyphase stator having a plurality of phase winding~ that may be individually energized by ~, an applied supply potential source. To sustain rotor rotation, the stator phase windings are se~uentially energized to produce a rotating magnetic field.
Motors of this type, therefore, require a method for determining rotor position so that the individual stator phase windings may be se~usntially energized at the proper time relative to rotor position.
Typically, optical devices, Hall effect devic2s or high frequency energized transformers are employed to *
11366C~7 detect rotor position and produce switch signals at the proper rotor positions to sequentially energize the stator phase windings in a manner to sustain rotor rotation. ~s these rotor position sensing devices require provision~ for mounting them on the motor and present maintenance problems, a commutatorless direct current motor drive system that does not require rotor position sensing devices is desirable.
It is, therefore, an object of this invention to provide an improved commutatorless direct current motor drive system.
It i9 another object of this invention to provide an improved commutatorless direct current motor drive system that is capable of initiating rotor rotation from standstill upon the application of supply potential and sustaining rotor rotation after start.
It is an additional object of this invention , to provide an improved commutatorless direct current motor drive system that provides for the sequential energization of the phase windings of a polyphase stator in response to the phase displaced alternating current potential waveforms induced in the stator phase windings by the magnetic field of the permanent magnet rotor upon rotor rotation.
In accordance with this invention, a commutatorless direct current motor drive system is 113~697 provided wherein the polyphase stator phase windings of the motor are individually energized in sequence by an applied supply potential source in response to the phase displaced alternating current potential waveforms induced in the stator phase windings by the magnetic field produced by a permanent magnet rotor upon rotor rotation.
For a better understanding of the present invention, together with additional objects, advan-tages and features thereof, reference is made to thefollowing description and acco~npanying drawing in which: .
Figure 1 sets forth the commutatorless direct current motor drive sy~tem of this invention in schematic form, and Figure 2 is a set of curves useful in understanding the operation of the circuit of Figure 1.
As point o reference or ground potential is the same point electrically throughout the system, it is illustrated in Figure 1 by the accepted schematic symbol and referenced by the numeral 5.
The supply potential source may be a con-ventional storage battery 3 or any other suitable direct current potential source having current and
2~ voltage capabilities consistent with the requirements of the application. In the interest of xeducing the complexity of Figure 1 of the drawing, specific con-nections between battery 3 and various portions of 1~3ti697 the system that require operating potential have not been shown. It is to be specifically understood, how-ever, that, upon the application of operating potential, all of the points of the system identified by a plus sign within a circle are connected to the positive polarity output terminal of battery 3 or any other direct current potential source that may be employed having direct current output voltage and current ratings consistent with the operating potential re~uirements of the circuitry of Figure 1.
The commutatorless direct current motor drive system of this invention employs four operational amplifier circuits~ In an actual embodimen~, the operational amplifier circuits employed are of the Norton type such as those marXeted commercially by the ~ational Semiconductor Corporation under the designation LM3900. As these operational amplifier circuits may be commercially available items well known in the art and, per se, form no part of this invention, each has been illustrated in Figure 1 of the drawing by the accepted schematic symbol for Norton type operational amplifiers. Furthermore, the ~orton type operational amplifier circuit is only an example of an operational amplifier circuit suitable for use with the system of this inventi.on, consequently, there is no intention or inference of a limitation thereto as other circuit elements having similar elec-trical characteristics may be substituted therefor wi~hout departing from the spirit of the invention.
~3~ig~jt Whereas ~he conventional operational am~lifier circuit differences input voltages, the ~orton type operational amplifier circuit differences input c~rrents. There-fore, large valued external input resistors are employed S to convert from input voltages to input currents.
Briefly, the ~orton type operational amplifier circuit operates in such a manner that when current flow into the plus (+) input terminal i5 of a magnitude greater than that 10wing into the minus (-) input terminal, the output signal of the device rises to a magnitude substantially e~ual to supply potential and when current flow into the minus (-) input terminal is of a magnitude greater than that flowing into the plus ~) input ter~inal, the output signal of the device goes to substantially ground potential.
The commutatorless direct current motor 6 includes a polyphase stator 7 having three stator phase windings A, B and C and a permanent magnet rotor 8 magnetized across the diameter thereof with north and south magnetic poles. The motor illustrated in Figure 1 is of the two-pole permanent magnet rotor type having a three-phase stator with one terminal end of each of the three stator phase windings connec-ted to a common node N. The permanent magnet rotor 8 is arranged to be rotated in magnetic coupling rela-tionship with the stator phase windings A, B and C
whereby ~pon rotor 8 rotation, the rotox 8 magnetic field induces alternating current potential waveforms in the stator phase windings A, B and C that are phase displaced from each other by the number of electrical aegrees determined by the number of stator phases.
With a three-phase stator as illustrated in Figure 1, t~ese induced alternating current potential waveforms are phase displaced from each other by 120 electrical degrees.
The supply potential souroe, battery 3 may be applied acro~s and disconnected from ~he co~nmutator-less direct current motor drive system of this inven-tion by a single pole-single thxow electrical switch 10 having a movable contact 11 and a stationary contact 12 or any other suitable electrical switching device.
In a manner later to be explained, stator phase windings A, B, and C may be individually en2r-gized by an applied supply potential source such as battery 3 through respective individual stator phase winding energizing circuits, each of which is arranged for connection across an external supply potential source. The energizing circuit for stator phase winding A includes lead 9, movable contact 11 and stationary contact 12 of switch 10, lead 13, node ~, stator phase winding A, lead 14, the current carrying elements of NPN transistox Darlington pair 15 and point oE reference or ground potential 5. The ener-gizing circuit for stator phase winding B includes lead 9, movable contact 11 and stationary contact 12 ~3~6'97 of switch 10, lead 13, node N, stator phase winding B, lead 16, the current carrying elements of NP~ transis-tor Darlington pair 17 and point of reference or ground potential 5. The energizing circuit for stator phase winding C includes lead 9, movable contact 11 and stationary contact 12 of switch 10, lead 13, node N, stator phase winding C, lead 18, the current carry-ing elements of NP~ transistor Darlington pair 19 and point of reference or ground potential 5. ~hese ener-gizing circuits are axranged for connection across anexternal supply potential source through lead 9 and switch 10 and through point of reference or ground potential S.
The commutatorless direct current motor drive system of thi~ invention is composed of one start circuit including the circuitry set forth within dashed-line rectangle 20 that is active only at or near zero permanent magnet rotor 8 rotational speed for initiating rotor 8 rotation from standstill whereby the phase displaced potential waveforms are initially induced in the stator phase windings A, B
and C and three identical commutation circuits, each including the circuitry set forth within respective dashed-line rectangles 21, 22 and 23. In a manner to be later brought out in detail, the con~utation cir-cuits 21, 22 and 23 are re~ponsive to the phase displaced potential waveforms induced in stator phase ~36697 windings ~, B and C for sustaining rotor 8 rotation by sequentially completing and later interrupting the respective hereinabove-described individual stato~
phase winding energizing circuits. Each of commuta-tion circuits 21, 22 and 23 corresponds to a respective stator phase winding A, B and C and each is operational to effect the completion of the sta~or phase winding energizing circuit for the stator phase winding to which it corresponds in response to each negative going portion o~ the potential wa~eform induced in that stator phase winding and to effect the inter-ruption of this energizing circuit in response to a predetermined potential level during a positive going portion of the potential waveform induced in another one of the stator phase windings whereby, after initi-ati~n of rotor 8 rotatio;l from standstill by start circuit 20, the stator phase windings A, B and C are se~uentially energized and later deenergized in response to the phase displaced alternating current 2~ potential waveforms induced in the stator phase windings A, ~ and C to produce a rotating magnetic field that sustains rotor 8 rotation.
Referring to the start circuit 20, the circuit combination including ~orton operational amplifier circuit 25, input resistors 26 and 27 and the feedback network including the parallel combina-tion of resistor Z4 and series connected capacitor 2
The commutatorless direct current motor drive system of this invention employs four operational amplifier circuits~ In an actual embodimen~, the operational amplifier circuits employed are of the Norton type such as those marXeted commercially by the ~ational Semiconductor Corporation under the designation LM3900. As these operational amplifier circuits may be commercially available items well known in the art and, per se, form no part of this invention, each has been illustrated in Figure 1 of the drawing by the accepted schematic symbol for Norton type operational amplifiers. Furthermore, the ~orton type operational amplifier circuit is only an example of an operational amplifier circuit suitable for use with the system of this inventi.on, consequently, there is no intention or inference of a limitation thereto as other circuit elements having similar elec-trical characteristics may be substituted therefor wi~hout departing from the spirit of the invention.
~3~ig~jt Whereas ~he conventional operational am~lifier circuit differences input voltages, the ~orton type operational amplifier circuit differences input c~rrents. There-fore, large valued external input resistors are employed S to convert from input voltages to input currents.
Briefly, the ~orton type operational amplifier circuit operates in such a manner that when current flow into the plus (+) input terminal i5 of a magnitude greater than that 10wing into the minus (-) input terminal, the output signal of the device rises to a magnitude substantially e~ual to supply potential and when current flow into the minus (-) input terminal is of a magnitude greater than that flowing into the plus ~) input ter~inal, the output signal of the device goes to substantially ground potential.
The commutatorless direct current motor 6 includes a polyphase stator 7 having three stator phase windings A, B and C and a permanent magnet rotor 8 magnetized across the diameter thereof with north and south magnetic poles. The motor illustrated in Figure 1 is of the two-pole permanent magnet rotor type having a three-phase stator with one terminal end of each of the three stator phase windings connec-ted to a common node N. The permanent magnet rotor 8 is arranged to be rotated in magnetic coupling rela-tionship with the stator phase windings A, B and C
whereby ~pon rotor 8 rotation, the rotox 8 magnetic field induces alternating current potential waveforms in the stator phase windings A, B and C that are phase displaced from each other by the number of electrical aegrees determined by the number of stator phases.
With a three-phase stator as illustrated in Figure 1, t~ese induced alternating current potential waveforms are phase displaced from each other by 120 electrical degrees.
The supply potential souroe, battery 3 may be applied acro~s and disconnected from ~he co~nmutator-less direct current motor drive system of this inven-tion by a single pole-single thxow electrical switch 10 having a movable contact 11 and a stationary contact 12 or any other suitable electrical switching device.
In a manner later to be explained, stator phase windings A, B, and C may be individually en2r-gized by an applied supply potential source such as battery 3 through respective individual stator phase winding energizing circuits, each of which is arranged for connection across an external supply potential source. The energizing circuit for stator phase winding A includes lead 9, movable contact 11 and stationary contact 12 of switch 10, lead 13, node ~, stator phase winding A, lead 14, the current carrying elements of NPN transistox Darlington pair 15 and point oE reference or ground potential 5. The ener-gizing circuit for stator phase winding B includes lead 9, movable contact 11 and stationary contact 12 ~3~6'97 of switch 10, lead 13, node N, stator phase winding B, lead 16, the current carrying elements of NP~ transis-tor Darlington pair 17 and point of reference or ground potential 5. The energizing circuit for stator phase winding C includes lead 9, movable contact 11 and stationary contact 12 of switch 10, lead 13, node N, stator phase winding C, lead 18, the current carry-ing elements of NP~ transistor Darlington pair 19 and point of reference or ground potential 5. ~hese ener-gizing circuits are axranged for connection across anexternal supply potential source through lead 9 and switch 10 and through point of reference or ground potential S.
The commutatorless direct current motor drive system of thi~ invention is composed of one start circuit including the circuitry set forth within dashed-line rectangle 20 that is active only at or near zero permanent magnet rotor 8 rotational speed for initiating rotor 8 rotation from standstill whereby the phase displaced potential waveforms are initially induced in the stator phase windings A, B
and C and three identical commutation circuits, each including the circuitry set forth within respective dashed-line rectangles 21, 22 and 23. In a manner to be later brought out in detail, the con~utation cir-cuits 21, 22 and 23 are re~ponsive to the phase displaced potential waveforms induced in stator phase ~36697 windings ~, B and C for sustaining rotor 8 rotation by sequentially completing and later interrupting the respective hereinabove-described individual stato~
phase winding energizing circuits. Each of commuta-tion circuits 21, 22 and 23 corresponds to a respective stator phase winding A, B and C and each is operational to effect the completion of the sta~or phase winding energizing circuit for the stator phase winding to which it corresponds in response to each negative going portion o~ the potential wa~eform induced in that stator phase winding and to effect the inter-ruption of this energizing circuit in response to a predetermined potential level during a positive going portion of the potential waveform induced in another one of the stator phase windings whereby, after initi-ati~n of rotor 8 rotatio;l from standstill by start circuit 20, the stator phase windings A, B and C are se~uentially energized and later deenergized in response to the phase displaced alternating current 2~ potential waveforms induced in the stator phase windings A, ~ and C to produce a rotating magnetic field that sustains rotor 8 rotation.
Referring to the start circuit 20, the circuit combination including ~orton operational amplifier circuit 25, input resistors 26 and 27 and the feedback network including the parallel combina-tion of resistor Z4 and series connected capacitor 2
3,~3~i9~7 and resistor 29 comprise a conventional monostable multivibrator circuit. As is well known in the art, the monostable multivibrator circuit normally operates in a stable state; may be triggered to an alternate state for a predetermined duration of time as estab-lished by an associated timing network and spontaneous-ly returns to the original stable state upon the ter-mination of the predetermined time duration. As the minus (-) input terminal of ~orton operational amplirier circuit 25 is connected to the positive polarity output terminal o~ the supply potential source through input resistor 26, the output signal of Norton ampliier circuit 25 upon junction 30 is substantially ground potential while this monostable multivibrator circuit is in the normal stable state. Upon the initial appli-cation of supply potential by electrically closing movable contact 11 of switch 10 to stationary contact 12, all of the capacitors of the circuit are discharged, consequently, an arbitrary phase winding A, B or C is generally energized and ~PN transistor 32 is not con-ductive. With NPN transistor 32 not conducting, capacitor 33 charges across the supply potential source through charging resistor 34. When capacitor 33 has charged to a direct current potential level of a magnitude sufficient to supply more curxent throu~h input resistor 27 to the plus (-~) input terminal o~
~orton operational amplifier cixcuit 25 than is supplied by the supply potential source to the minus (-) input terminal thereof throu~h input resistor 26, the rnonostable multivibrator circuit is triggered to the alternate state in which the output signal thereof upon junction 30 rises to a potential level approxi-mately two diode drops less than that of the supply potential. While the monostable multi~ib.rator circuit is in the alternate state, the output direct current potential signal pulse upon junction 30 supplies base-emitter drive current to NPN transistor 32 throughresistor 36. This drive current triggers NPN transistor 32 conductive through the collector-emitter electrodes to discharge capacitor 33. Additionally, the monostable multivibrator circuit output signal pulse upon junction 30 is applied to and supplies current through diode 37, resistor 38 and lead 39 to the plus (~) input terminal of Norton operational amplifier circuit 40 of commuta-tion circuit 21 supplies current through diode 41, resistor 42 and lead 43 to the minus (-) input texminal of Norton operational amplifier circuit 50 of commuta-tion circuit 22, supplies charge current for capacitor 44 through charging resistor 45 and supplies current through diode 46, resistor ~7 and lead 48 to the minus (-) input terminal of Norton operational amplifier circuit 60 of commutation circuit 23. The flow of current throuyh diode 37, resistor 38 and lead 39 into the plus (~) input terminal of ~orton operational ampli-fier circuit 40 forces the triggering of this device to the condition in which the output signal thereofupon junction 51 is of a le~el substantially equal to supply potential; the flow of current thxough diode 41, resistor 42 and lead 43 into the minus (-~ input ter-minal of Norton operational amplifier circuit 50 forcesthe triggering of this device to the condition in which the output signal thereof upon ~unction 52 is substan-tially ground potential: the flow of current through diode 46, resistor 47 and lead 48 into the minus (-) input terminal of Norton operational amplifier circuit 60 forces the triggering of this device to the condi-tion in which the output signal thereof upon junction :53 is substantially ground potential and the flow of charge current through capacitor 44 and resistor 45 charge~ capacitor 44 to a potential level equal to approximately two diode drops less than that or the supply potential with the ~unction between capacitor 44 and resistor 45 being approximately one diode drop above ground potential. The positive polarity poten-tial signal upon junction 51 of commutation circuit 21supplies base-emitter drive current through resistor 54 to the NPN transistor Darlington pair 15 including an emitter resistor 56 to trigger this ~PN transistox Darlington pair conductive through the current carrying elements thereof. Upon the conduction of NPN transis-tor Darlington pair 15, the previously described stator phase winding A energizing circuit is completed and may be traced from the positive polarity output terminal o ~3~ 7 battery 3, throuyh lead 9, closed contacts 11 and 12 of switch 10, node ~, phase winding A, lead 1~, the current carrying elements of NPN transistor ~arlington pair 15 and point of reference or ground potential 5 to the negative polarity output terminal of battery 3. As substantially ground potential is present upon junc-tions 52 and 53, the individual energizing circuits for phase windings B and C are not completed at this time, consequently, these phase windings are not energized.
While the monostable multivibrator circuit of start circuit 20 is in the alternate state, rotor 8 aligns with the magnetic field produced by energized stator phase winding A and settles in this aligned position.
Therefore, the duration of time that the monostable multivibrator circuit of start circuit 20 remains in the a]ternate state is determined by ~he period of time necessary for rotor 8 to align with the magnetic field produced by energized stator phase winding A. In the actual embodiment, this time period is of the order of 0.3 of a second. At the conclusion of the timing period as determined by the RC time constant of timing capacitor 28 and resistor 29 in the feedback circuit of Norton operational amplifier circuit 25 o the mono-stable multivibrator circuit of start circuit 20, this monostable multivibrator circuit spontaneously reverts to the stable condition of operation in which the output signal thereof upon junction 30 is of substantially ground potential. With a substantially ground potential ~l36~7 signal upon junction 30, timing capacitor 28 discharges through diode 55 to reset staxt circuit 20. As the potential across capacitor 44 can not change instantan-eously when the signal upon ~unction 30 goes to sub-stantially ground potential, the potential upon thejunction between capacitor 44 and resistor 45 goes negative by an amount equal to the reduction in poten-tial upon junction 30. ~or example, with a 12 volt direct current supply potential sourca, the potential upon junction 30 is of the order of 11 volts and the potential upon the junction between capacitor 44 and resistor 45 is of the order of 0.5 volt while the monostable multivibrator circuit of start circuit 20 is in the alternate state. When this monostable multi-vibrator circuit reverts to the stable state, thepotential upon junction 30 goes from 11 volts to approx-imately 0.5 volt and the potential upon the junction between capacitor 44 and resistor 45 goes to the order , of negative 10.5 volts. As a consequence, current is drawn from the minus (-) input terminal of ~orton oper-ational amplifier circuit 50 of commutation circuit 22 throu~h lead 43 and resistor 45 into capacitor 44 to discharge this device. The duxation of this signal pulse is established b~ the RC time constant of resistor 45 and capacitor 44 and is applied to the minus (-) inpu~
terminal of Norton operational amplifier circuit 50. As a result of this flow of current out of the minus (-) input ter~inal of Norton operational amplifier cixcuit 1~3~7 ~0, this device abruptly switches to the condition in which the output signal thereof upon junction 52 i5 of a magnitude substantially e~ual to supply potential.
This positive polarity potential signal upon junction 52 supplies base-emitter drive current through resistor 57 to the NPN transistor Darlington pair 17 including an emitter resistor 58 to trigger this NPN transistor ~arlington pair conductive through the current carrying elements thereof. Upon the conduction of NPN transistor Darlington pair 17, the previously described statox phase winding ~ energizing circuit is completed and may be traced from the positi~e polarity output terminal of battery 3, through lead 9, closed contacts 11 and 12 of switch 10, node N, stator phase winding B, lead 16, the current carrying elements of NP~ transistor Darlington pair 17 and point of reference or ground potential 5 to the negative polarity output terminal of battery 3.
Upon the energization of stator phase winding B, the resultant magnetic field produced by energized stator phase windings A and B is to the left, as viewing Figure 1, of that produced by energized stator phase winding A.
This shift of stator magnetic field initiates rotation of rotor 8 in a counterclockwise direction at a speed greater than the minimum commutation speed. Start circuit 20, therefore, efects the initiation of rotor 8 rotation from standstill at a speed greater than minimum commutation speed. For a start o~ rotor 8 xotation in a clockwise direction, the energization of 1136~i~7 stator phase winding C rather than stator phase winding B may be forced after rotor 8 has aligned with the magnetic field produced by energized stator phase winding A . This may be effected by connecting the combination of series connected capacitor 44 and resis-tor 45 to the minus (-) input terminal of Norton operational amplifier circuit 60 of commutation circuit 23~ As will be brought out later is this speciica-tion, the system o~ this invention operates to sustain rotor 8 rotation after the initiation of rotor 8 rota-tion from standstill.
From the foregoing description, it is appar-ent that start circuit 20 includes a monostable multi-vibrator circuit that produces a first electrical output signal pulse of a predetermined duration a~
established by the RC time constant of timing capacitor 28 and resistor 29 upon the application of supply potential and a capacitor 44 and a resistor 45 that , produces a second opposite polarity electrical output signal pulse of a predetermined duration as established by the RC time constant of capacitor 44 and resistor 4S upon the termination of the first output signal pulse. In a manner to be later explained, start cir-cuit 20 is disabled while rotor 8 rotation is sustained by the operation oE the system of this invention.
While rotor 8 is rotating, the magnetic field of rot~ting rotor 8 induces alternating current poten-tial waveforms in stator phase windings A, B and c i97 that are phase displaced ~rom each other by 120 elec-trical degrees and are superimposed upon the direct current potential level of the supply potential souxce as illustrated by the curve of Figure 2A wherein the supply potential source potential level is referenced by the notation B+. These induced potential waveforms are of a frequency and amplitude directly proportional to the rotational speed of rotor 8. However, in a manner to be later explained, the NPN transistor Darlington pairs 15, 17 and 19 are conductive part of the time and not conductive part of the time. While NP~ transistor Darlington pair 15 is not conductive, the potential level upon junction 63 is substantially egual to the sum of the alternating current potential waveform induced in stator phase winding A by the rotor 8 magnetic field and the potential level of the supply potential source and while ~P~ transistor Darlington pair 15 is conductive, the potential level upon junc-tion 63 is substantially ground, as illustrated by the curve of Figure 2B. While ~P~ transistor Darlington pair 17 is not conductive, the potential level upon junction 64 is substantially equal to the sum of the alternating current potential waveform induced in stator phase winding B by the rotor 8 magnetic field and the potential level of the supply potential source and wh.ile NPN transistor Darlington pair 17 i5 conductive, the potential level upon junction 64 is substantially 1~3~69 ~
ground, as illustrated by the curve of Figure 2C.
While NP~ transis-tor Darlington pair 19 is not conduc-tive, the potential level upon junction 65 is substan-tia;ly egual to the sum of the alternating current potential waveform induced in stator phase winding C
by the rotor 8 ma~netic field and the potential level of the supply potential source and while ~PN transistor Darlington pair 19 is conductive, the potential level upon junction 65 i5 substantially ground, as illustra-ted ~y the curve of Figure 2D.
Commutation of ~PN transistor Darlington pairs 15, 17 and 19 is achieved by sensing the poten-tial level of the stator phase windings A, B and C.
This commutation is effected by commutation circuits 21, 22 and 23 that are responsive to the phase dis-placed potential waveforms that are induced in stator phase windings A, B and C by the rotating magnetic field of rotor 8. The potential level of stator phase winding A appears upon junction 63 and is filtered by resistor 67, diode 68, capacitor 69 and diode 70. The potential level of stator phase winding ~ appears upon junction 64 and is filtered by resistor 71, diode 72, capacitor 73 and diode 74~ The potential level o.
stator phase winding C appears upon junction 65 and is filtered by resistor 75, diode 76, capacitor 77 and diode 78. In addition, it is the function of diodes 70, 74 and 78 to prevent the potential upon respecti~e ~13~6g7 junctions 81, 82 and 83 from increasing to a potential level greater than one diode drop above the level of the supply potential. The combination of resistor 67, diode 68 and capacitor 69 functions as a voltage peak follower circuit whereby the charge upon capacitor 69 follows the change of potential level upon junction 63;
the combination of resistor 71, diode 72 and capacitor 73 functions as a voltage peak follower circuit whereby the charge upon capacitor 73 follows the change of potential level upon junction 64; and the combination of resistor 75, diode 76 and capacitor 77 functions as a voltage peak follower circuit whereby the charge upon capacitor 77 follows the change of potential level upon junction 65.
In each of the curves of Figure 2, the supply potential level is referenced by the notation B+.
Referring to Figure 2, upon the initiation at time To of rotor 8 rotation in a counterclocXwise direction at a speed greater than the minimum commutation speed in a manner hereinabove explained with reference to start circuit 20, the potential level upon each o junctions 63 and 64 is substantially ground, as illustrated by respective curves 2B and 2C, for the reason that both NPN transistor Darlington pairs 15 and 17 are conduc-tive through the current carrying elements thereof andthe potential upon junction 65 is of substantially supply potential for the reason that transistor Darling-ton pair 19 is not conductive through the current 1~
1~66'~7 carrying elements thereof, as illustrated by curve 2D.
As rotor 8 rotates between times To and Tl o~
Figure 2, the signal upon each of junctions 63 and 64 remains at substantially ground potential, as illustrated by respective curves 2B and 2C, and the alternating cur-rent potential waveform induced in phase winding C by the magnetic field of rotating rotor 8 increases in a positive going direction from the supply potential level and appears upon junction 65, as illustrated by curve 2~.
This increasing potential upon junction 65 charges capacitor 86 o~ commutation circuit 21 through lead 84 and resistor 85. When, at time Tl, capacitor 86 has charged to a direct current potential level o~ a magni-tude sufficient to supply more current through input resistor 87 to the minus (-) input terminal of ~orton operational ampli~ier circuit 40 than is supplied to the plus (+) input terminal thereof through input resistor 88 from the positive polarity output terminal o~ the supply potential source, Norton operational amplifier circuit 40 is abruptly triggered to the condition in which the output signal thereof upon junction 51 is of substantially ground potential. With a substantially ground potential signal upon junction 51, NP~ transistor Darlington pair 15 is triggered not conductive to inter-rupt the previously described stator phase ~inding ~energizing circuit. Upon the interruption of this ener-gizing circuit, the alternating currenk potential wave-form induced in phase winding ~ by ~he magnetic field of 20rotating rotor 8 is superimposed upon the direct current supply potential and appears upon ]unction 63, as illus-trated by the curve 2B.
As rotor 8 rotates between times Tl and T2, the alternating current potential waveform induced in phase winding A by the magnetic field of rota-ting rotor 8 that appears upon junction 63 passes through B+ from a negative to a positive polarity direction and further increases in a positive going direction toward the maxi-mum positive polarity level, as illustrated by curve 2B;the signal upon junction 6~ remains at substantially ground potential as ~P~ transistor Darlington pair 17 is still conductive, as illustrated by curve 2C; and the alternating current potential waveform induced i.n phase winding C by the magnetic field of rota-tiny rotor 8 that appears upon junction 65 increases to and passes through the maximum positive polarity level and decreases in a negative going direction through B~, as illustrated by eurve 2D. The potential waveform upon ~unetion 65 is followed by a corresponding eharge upon capacitor 77.
When~ at time T2, the charge upon capacitor 77 has decreased to a direct current potential level of a magnitude that is insufficient to supply more eurrent through input resistor 97 to the minus (-) input terminal of ~orton operational ampli-Eier circuit 60 than is sup-plled to the plus (+) input terminal thereof through input resistor 98 from the positive polarity output terminal of the supply potential source~ Norton 13 3~697 operational amplifier eircuit 60 is abruptly triggered to the condition in which the output signal thereo:E upon junetion 53 is o-f a positive polarity potential level substantially equal to the supply potential level. This positive polari'cy potential signal upon junction 53 sup-plies base-emitter drive current throua,h resistor 99 to NPN transistor Darlington pair 19, including an e~nitter resistor 59, to trigger this transistor Darlington pai.r eonductive throu~h the current earrying element~ thereo~
~0 to eomplete the previously described stator phase winding C energizing eireuit and the potential signal upon june-tion 65 goes to substantially ground potential, as illustrated by eurve 2D.
As rotor 8 rotates between times T~ and T3, the alternating eurrent potential waveform induced in phase winding A by the magnetie field o~ rotating rotor 8 that appears upon junetion 63 continues to increase in a posi-tive going direction toward the maximum positive polarity level, as illustrated by eurve 2B; the signal upon junc-tion 64 remains at substantially ground potential as NP~transistor Darlington pair 17 is still eonductive, as illustrated by curve 2C; and the signal upon junction 65 remains at substantially ground potential as NPN transis-tor Darlington pair 19 is still conductive, as illustrated by eurve 2D. The increasing potential level upon junction 63 hetween times T2 and T3 charges capaeitor 91 o~ co~mu-tation eircuit 22 through lead 89 and resistor 90. When, at time T3, eapacitor 91 has eha.rged -to a dixect eurrent ~13~7 potential level oE a magnitude suLficient to supply more current through input resistor 92 to -the minus (-) input terminal of ~orton operational amplifier circuit 50 than is supplied to the plus (~) input terminal thereo~
5 through input resistor 93 fxom the positive polarity output terminal of the supply potential source, ~orton operational amplifier circuit 50 is abruptly triggered to the condition in which the output signal thereof upon junction 52 is o substantially ground potential. With a substantially ground potential signal upon junction 52, NPN transistor Darlington pair 17 is triggered not con-ductive to interrupt the previously described stator phase winding B energizing circuit and capacltor 86 of commutation circuit 21 discharges through diode 94, lead 96 and the emitter-collector electrodes of PNP
transistor 95. Upon the interruption of the stator phase winding B energizing circuit, the alternating current potential wave~orm induced in phase winding B
by the magnetic field of rotating rotor 8 is super- , imposed upon the direct current supply potential and appears upon junction 64, as illustrated by curve 2C.
As rotor 8 rotates between times T3 and Ta~
the alternating current potential waveform induced in phase winding B by the magnetic field of rotating rotor 8 that appears upon junction 64 passes through B+ from a negative to a positive polarity direction and further increases in a positive going direction toward the maxi-mum pos:tive polaxity level, as illustrated by curve 2C, 113~ 7 the signal upon junction 55 rema:Lns at substantially ground potential as NPN transis-tor Darlington pair 19 is still conductive, as illustrated by curve 2D; and the alternating current potential waveform induced in phase winding A by the magnetic ~ield of rotating rotor 8 that appears upon junction 63 increases to and passes through the maximum positive polarity level and de-creases in a negative going direction through B+, as illustrated by curve 2B. The potential waveform upon junction 63 is followed by a corresponding charge upon capacitor 69. When, at time T4, the charge upon capacitor 69 has decreased to a direct current poten-tial level of a magnitude that is insufficient to supply more current through input resistor 110 to the minus (-) input terminal of Norton operational amplifier circuit 40 thal; is suppl'ed to the plus (~) input terminal thereof through input resistor 88 from the positive polarity output terminal o~ the supply potential source, Norton operational amplifier circuit 40 is abruptly triggered to the condition in which the output signal thereof upon junction 51 is o~ a positive polarity potential level substantially equal to the supply potential level. This positive polarity potential signal upon junction 51 supplies base-emitter drive current through resistor 54 to NPN transistor Darling-ton pair 15 to trigger this transistor Darlington pair conductive through the current carrying elements thercof to complete the prcviousl~ described stator phase ~3~6~ !7 winding ~ energizing circuit and the potential signal upon junction 63 goes to substantially c~rourld poten-tial, as illustrated by curve 2B.
As rotor 8 rotates between times T4 and T5, the alternating current potential waveform induced in phase winding B by the magnetic field of rotating rotor 8 that appears upon junction 64 continues to increase in a positive going direction toward the maximum posi-tive polarity level, as illustrated by curve 2C the signal upon junction 65 remains at substantially ground potential as ~P~ transistor Darlington pair 19 is still conductive, as il.lustrated by curve 2D; and the signal upon junction 63 remains at substantially ground poten-tial as ~PN transistor Darlington pair 15 is still conductive, as illustrated by curve 2B. The increas-ing potential level u.pon junction 64 between times T4 and T5 charges capacitor 100 of commutation circuit 23 through lead 101 and resistor 102. When, at time T5, capacitor 100 has charged to a direct current potential level of a magnitude sufficient to supply more current through input resistor 103 to the minus (-) input terminal of ~orton operational amplifier circuit 60 than is supplied to the plus (+) input terminal thereof through input resistor 9~ from the positive polarity output terminal of the supply potential source, Norton operational amplifier circuit 60 is abruptly triggered to the con~ition in ~hich the output signal thereo-f upon junction 53 is of substantially ground potential.
~3~ 7' With a substantially ground potential signal upon junction 53, NP~ transistor Darlington pair 19 is triggered not conductive to interrupt the previously described stator phase winding C energizing circuit and capacitor 91 of commutation circuit 22 discharges through diode 104, lead 105 and the emi-tter-collector electrodes of PNP transistor 106. Upon the interrup-tion o:E the stator phase winding C energizing circuit, -the alternating current potential waveEorm induced in phase winding C by the magnetic field o~ rotatiny rotor 8 is superimposed upon the direct current supply poten-tial and appears upon junction 6S, as illustra-ted by curve 2D.
As rotor 8 rotates between times T5 and T6, the alternating current potential waveiorm induced in phase winding C by the magnetic ~.ield of rotating -otor 8 that appears upon junction 65 passes through B+ from a negative to a positive polarity direction and further increases in a positive going direction toward the maxi- , mum positive polarity level, as illustrated by curve 2D;
the signal upon junction 63 remains at substantially ground potential as ~P~ transistor Darlington pair 15 is still conductive, as illustrated by curve 2B, and the alternating current poten-tial waveEorm induced in phase winding B by the magnetic field o~ rotati.ng rotor 8 that appears upon junction 64 inc:reases to and passe.s through the maxlmum positive polarity level and ae-creases in a neyative going direction throuyh B-~, as 113~69~7 illustrated by curve 2C. The potential waveform upon junction 64 is follo-~ed by a corresponding ch~rge upon capacitor 73. When, at time T6, the charge upon capaci~
tor 73 has decreased to a direct current potential level oE a magnitude that is insufficient to supply more current through input resistor 121 to the minus (-) input terminal of ~orton operational amplifier circuit 50 than is supplied to the plus (~) input terminal thereof through input resiscor 93 from the positive polarity outpu-t terminal of the supply potential source, Norton operational ampli~ier circuit 50 is abruptly triggered to the condition in which the output signal thereof upon junction 52 is o~ a positive polarity potential level substantially equal to the supply potential level. This positive polarity potential signal upon junction 52 supplies base-emitter drive current through resistor 57 to ~P~ transistor Darling-ton pair 17 to trigger this transistor Darlington pair conductive through the current carrying elements thereof to complete the previously described stator phase winding B energizing circuit and the potential signal upon junction 64 goes to substantially qround potential, as illustrated by curve 2C.
As rotor 8 rotates between times T6 and T7, -the alternating current potential waveform induced in phase winding C by che magnetic field of rotating rotor 8 that appears upon juncti.on 65 continues to increase in a positive going direct;on toward the maximum 1~3~ 7 positive polarity level, as illustrated by curve 2D
the signal upon junction 63 remains at substantially ground potential as NPN transistor Darlington pai,r 15 is still conductive, as illustrated by curve 2B; and the signal upon junction 64 remains at substantially ground potent.ial as NPN transistor Darlington pair 17 is still conductive, as illustrated by curve 2C. The increasing potential level upon junction 65 between times T6 and T7 charges capacitor 86 of commutation circuit 21 through lead 84 and resistor 85. ~hen, at time T7, capacitor ~6 has charged to a direct current potential level o a magnitude sufficient to supply more current through input resistor 87 to the minus (-) input terminal of Norton operational amplifier circuit 40 than is supplied to the plus (~) i.nput terminal thereof through input resistor 8~ ~rom the positive polarity output terminal of the supply potential source, Norton operational amplifier circuit 40 is abruptly triggered to the condition in which the output signal thereof upon junction 51 is of substanti-ally ground potential. With a substantially ground potential signal upon junction 51, ~PN transistor Darlington pair 15 is triggered not conductive to interrupt the previously described stator phase winding A energizing circuit ana capacitor 100 of comrnutation circuit 23 discharges through diode 112, lead 115 and the ernit-ter-collector electrodes of PNP
1~3~ 7 trans.istor 120. Upon the interruption of the stator phase winding A energizing circuit, the alternating current potential waveform induced in phase winding ~ by the magnetic field of rotating rotor 8 is super-imposed upon the direct current supply potential andappears upo~ junction 63, as illustrated by curve 2B.
The cycle of events just described repeats so long as the application of su~ply potential is maintained through switch lO. Referring to Figure 2, after initial rotor start from standstill and beginning with time T2, stator phase winding C, stator phase winding A and stator phase winding B
are sequentially energized in that order repeatedly.
This seauential stator phase winding energi7ation produces a rotating magnetic field in a manner well known in the art that sustains rotor rotation. For rotor rotation in the opposite direction, the sequence of stator phase winding energization would be reversed by reversing the connection of the terminal end opposite node ~ of any two of leads 14, 16 and 18.
It is apparent from the foregoing descrip-tion that each of commutation circuits 21, 22 and 23 ~.~36~i97 corresponds to a respective stator phase winding A, B
and C and that these commutation circuits are responsive to the alternating current phase displaced potential waveforms induced in stator phase windings A, ~ and C
for sustaining rotor 8 rotation after initial start from standstill by sequentially completing and later interrupting the respective individual stator phase winding energizing circuits that results in a rotating magnetic field.
Each of commutation circuits 21, 22 and 23 includes a Norton operational amplifier circuit and an ~PM transistor Darlington pair. Each combination of Norton operational amplifier circuit 40 and NP~ tran-sistor Darlington pair 15 of commutation circuit 21, ~orton operation amplifier circuit 5~ and NPN transis-tor Darlington pair 17 of commutation circuit 22 and Norton operational amplifier circuit 60 and ~P~ tran-sistor Darlington pair l9 is an electrically operable switching arrangement that is capable of being operated ~, to first and second operating conditions in response to the application thereto of electrical signals of a value less than and greater than a predetermined magni-tude and is effective to complete and interrupt the stator phase winding to which each corresponds when in the first and second operating conditions, respectively.
The switch point of each is determined by the supply potential level and the ohmic value o respective input resistors 88, 93 and 98 that determines the predeter-1~3~697 mined magnitude that the applied electrical signals must be less than and greater than. When the electri-cal signal applied to these swi.tching arrangements is of a level less than the predetermined magnitude, the applied electrical signal supplies less current to the minus (-) input terminal of the ~orton operational amplifier circuit than is supplied to the plus (~) input terminal, consequently, the switching arrangement is triggered to the operating condition in which ~he stator phase winding energizing circuit for the stator phase winding to which it corresponds is completed and when the applied electrical signal is of a level greater than the predetermined magn.itude, the applied signal supplies more current into the m.inus (-) input terminal of the Norton operational amplifier circuit than is supplied to the plus (~) input terminal, con-se~uently, the switching arrangement is triggered to the operating condition in which the stator phase winding energizing circuit for the stator phase winding to which it corresponds is interrupted. The potential waveform induced in stator phase winding A is applied to the minus (-~ input terminal of Norton operational amplifier circuit 40 of the corresponding switching arrangement through resistor 67, diode 68, capacitor 25 69 and resistor 110. The potential waveform induced in stator phase winding B is applied to the minus (-) input terminal of Norton operational amplifier circuit 50 of the corresponding switching arrangement through 69~
resistor 71, diode 72, capacitor 73 and resistor 121.
The potential waveform induced in stator phase winding C is applied to the minus ~-) input terminal of ~orton operational amplifier circuit 60 of the corresponding switching arrangement through resistor 75, diode 76, capacitox 77 and resistor 97. The potential waveform induced in stator phase winding A is applied to the minus (-) input terminal of Norton operational ampli-fier circuit 50 of the switching arrangement that corresponds to another stator pha.se winding B through lead 89, resistor 90, capacitor 91 and resistor 92.
The potential waveform induced in stator phase winding B is applied to the minus (-) input terminal of ~orton operational amplifier circuit 6Q of the switching arrangement that corresponds to another stator phase winding C through lead lOl, resistor 102, capacitor 100 and resistor 103. The potential waveform induced in stator phase winding C is applied to the minus ~-) input terminal of Norton operational amplifier circuit 40 of the switching arrangement that corresponds to another stator phase winding A through lead 84, resistor 85, capacitor 86 and resistor 87.
The combination of resistor 85 and capacitor 86 of commutation circuit 21 delays the application of the potential waveform induced in stator phase winding C to the minus (-) input terminal of Norton operational amplifier circuit 40 of commutation circuit 21: the combination of resistor 90 and capacitor 91 delays the 1~3~6~7 application of the potential waveform induced in stator phase winding ~ to the minus (-) input terrninal of Norton opera~ional amplifier circuit 50 of commutation circuit 22 and the cor~ination of resistor 102 and capacitor 100 delays the application of the potential waveform induced in stator phase winding B to the minus (-) input terminal of ~orton operational amplifier cir-cuit 60 of commutation circuit 23. By changing the delay introduced by these circuits, the period o con-duction of each of ~P~ transistor Darlington pairs 15,17 and 19 may be selected. As a result of the delay introduced by these resistor-capacitor cor~inations, each stator phase winding is deenergized at a time after the next stator phase winding in the seguence is ener-1~ gized as determined by this delay. These resistor-capacitor co~binations are so designed that each of capacitors 86, 91 and 100 charge through respective resistors 85, 90 and 102 at a xate that increases with the amplitude of the potential waveform induced in the respective stator phase winding to which each is con-nected. Conseguently, these resistor-capacitor cor~inations introduce a variable delay that is deter-mined by the motor speed, the lower the motor speed, the longer the delay period, and vice versa.
In a manner hereinabove explained in detail, while the drive system o this invention is sustaining rotor 8 rotation in response to the phase displaced potential waveforms induced in stator phase windings A, 1~36697 B and C, Norton operational amplifier circuit 60 is triggered to the condition in which the output signal thereof upon junction 53 is of a positive polarit~ and o a magnitude substantially equal to supply potential during each negative half cycle of the potential wave-form induced in stator phase winding C and is triggered to the condition in which the output signal thereor is substantially ground potential during each positive half cycle of the potential waveform induced in stator phase winding C. This signal is applied through lead 122, resistor 123 and coupling capacitor 124 to the base electrode of ~P~ transistor 32. While this signal is of a positive polarity, base-emitter drive current is supplied thereby to ~P~ transistor 32 to trigger this device conductive through the collector-emitter elec-trodes to provide a discharge path for capaci~or 33 during each negative half cycle of the potential waveform induced in stator phase winding C. While this signal is of ground potential, coupling capacitor 124 discharges through diode 125. The RC time constant of capacitor 33 and charging resistor 34 is so arranged that capacitor 33 does not charge to a sufficient potential level to efect the triggering of Norton operational amplifier circuit 25 between successive negative polarity half cycles of the potential waveform induced in phase windingC. Therefore, 50 long as the system of this invention is sustaining roto.r rotation in response to the potential wavefo~ns induced in the stator phase windings, start ~3ti~97 circuit 20 is maintained disabled. Zener diodes 126, 127 and 12B protect respective ~P~ transistor DarlingtOn pairs against possibly destructive high voltage transi-ents.
~hile a preferred embodiment o~ the present invention has been shown and described, it will be obvious to those skilled in the art that various modifi-cations and substitu~ions may be made without departing from the spirit of the invention which i5 to be limited only within the scope o the appended claims.
~orton operational amplifier cixcuit 25 than is supplied by the supply potential source to the minus (-) input terminal thereof throu~h input resistor 26, the rnonostable multivibrator circuit is triggered to the alternate state in which the output signal thereof upon junction 30 rises to a potential level approxi-mately two diode drops less than that of the supply potential. While the monostable multi~ib.rator circuit is in the alternate state, the output direct current potential signal pulse upon junction 30 supplies base-emitter drive current to NPN transistor 32 throughresistor 36. This drive current triggers NPN transistor 32 conductive through the collector-emitter electrodes to discharge capacitor 33. Additionally, the monostable multivibrator circuit output signal pulse upon junction 30 is applied to and supplies current through diode 37, resistor 38 and lead 39 to the plus (~) input terminal of Norton operational amplifier circuit 40 of commuta-tion circuit 21 supplies current through diode 41, resistor 42 and lead 43 to the minus (-) input texminal of Norton operational amplifier circuit 50 of commuta-tion circuit 22, supplies charge current for capacitor 44 through charging resistor 45 and supplies current through diode 46, resistor ~7 and lead 48 to the minus (-) input terminal of Norton operational amplifier circuit 60 of commutation circuit 23. The flow of current throuyh diode 37, resistor 38 and lead 39 into the plus (~) input terminal of ~orton operational ampli-fier circuit 40 forces the triggering of this device to the condition in which the output signal thereofupon junction 51 is of a le~el substantially equal to supply potential; the flow of current thxough diode 41, resistor 42 and lead 43 into the minus (-~ input ter-minal of Norton operational amplifier circuit 50 forcesthe triggering of this device to the condition in which the output signal thereof upon ~unction 52 is substan-tially ground potential: the flow of current through diode 46, resistor 47 and lead 48 into the minus (-) input terminal of Norton operational amplifier circuit 60 forces the triggering of this device to the condi-tion in which the output signal thereof upon junction :53 is substantially ground potential and the flow of charge current through capacitor 44 and resistor 45 charge~ capacitor 44 to a potential level equal to approximately two diode drops less than that or the supply potential with the ~unction between capacitor 44 and resistor 45 being approximately one diode drop above ground potential. The positive polarity poten-tial signal upon junction 51 of commutation circuit 21supplies base-emitter drive current through resistor 54 to the NPN transistor Darlington pair 15 including an emitter resistor 56 to trigger this ~PN transistox Darlington pair conductive through the current carrying elements thereof. Upon the conduction of NPN transis-tor Darlington pair 15, the previously described stator phase winding A energizing circuit is completed and may be traced from the positive polarity output terminal o ~3~ 7 battery 3, throuyh lead 9, closed contacts 11 and 12 of switch 10, node ~, phase winding A, lead 1~, the current carrying elements of NPN transistor ~arlington pair 15 and point of reference or ground potential 5 to the negative polarity output terminal of battery 3. As substantially ground potential is present upon junc-tions 52 and 53, the individual energizing circuits for phase windings B and C are not completed at this time, consequently, these phase windings are not energized.
While the monostable multivibrator circuit of start circuit 20 is in the alternate state, rotor 8 aligns with the magnetic field produced by energized stator phase winding A and settles in this aligned position.
Therefore, the duration of time that the monostable multivibrator circuit of start circuit 20 remains in the a]ternate state is determined by ~he period of time necessary for rotor 8 to align with the magnetic field produced by energized stator phase winding A. In the actual embodiment, this time period is of the order of 0.3 of a second. At the conclusion of the timing period as determined by the RC time constant of timing capacitor 28 and resistor 29 in the feedback circuit of Norton operational amplifier circuit 25 o the mono-stable multivibrator circuit of start circuit 20, this monostable multivibrator circuit spontaneously reverts to the stable condition of operation in which the output signal thereof upon junction 30 is of substantially ground potential. With a substantially ground potential ~l36~7 signal upon junction 30, timing capacitor 28 discharges through diode 55 to reset staxt circuit 20. As the potential across capacitor 44 can not change instantan-eously when the signal upon ~unction 30 goes to sub-stantially ground potential, the potential upon thejunction between capacitor 44 and resistor 45 goes negative by an amount equal to the reduction in poten-tial upon junction 30. ~or example, with a 12 volt direct current supply potential sourca, the potential upon junction 30 is of the order of 11 volts and the potential upon the junction between capacitor 44 and resistor 45 is of the order of 0.5 volt while the monostable multivibrator circuit of start circuit 20 is in the alternate state. When this monostable multi-vibrator circuit reverts to the stable state, thepotential upon junction 30 goes from 11 volts to approx-imately 0.5 volt and the potential upon the junction between capacitor 44 and resistor 45 goes to the order , of negative 10.5 volts. As a consequence, current is drawn from the minus (-) input terminal of ~orton oper-ational amplifier circuit 50 of commutation circuit 22 throu~h lead 43 and resistor 45 into capacitor 44 to discharge this device. The duxation of this signal pulse is established b~ the RC time constant of resistor 45 and capacitor 44 and is applied to the minus (-) inpu~
terminal of Norton operational amplifier circuit 50. As a result of this flow of current out of the minus (-) input ter~inal of Norton operational amplifier cixcuit 1~3~7 ~0, this device abruptly switches to the condition in which the output signal thereof upon junction 52 i5 of a magnitude substantially e~ual to supply potential.
This positive polarity potential signal upon junction 52 supplies base-emitter drive current through resistor 57 to the NPN transistor Darlington pair 17 including an emitter resistor 58 to trigger this NPN transistor ~arlington pair conductive through the current carrying elements thereof. Upon the conduction of NPN transistor Darlington pair 17, the previously described statox phase winding ~ energizing circuit is completed and may be traced from the positi~e polarity output terminal of battery 3, through lead 9, closed contacts 11 and 12 of switch 10, node N, stator phase winding B, lead 16, the current carrying elements of NP~ transistor Darlington pair 17 and point of reference or ground potential 5 to the negative polarity output terminal of battery 3.
Upon the energization of stator phase winding B, the resultant magnetic field produced by energized stator phase windings A and B is to the left, as viewing Figure 1, of that produced by energized stator phase winding A.
This shift of stator magnetic field initiates rotation of rotor 8 in a counterclockwise direction at a speed greater than the minimum commutation speed. Start circuit 20, therefore, efects the initiation of rotor 8 rotation from standstill at a speed greater than minimum commutation speed. For a start o~ rotor 8 xotation in a clockwise direction, the energization of 1136~i~7 stator phase winding C rather than stator phase winding B may be forced after rotor 8 has aligned with the magnetic field produced by energized stator phase winding A . This may be effected by connecting the combination of series connected capacitor 44 and resis-tor 45 to the minus (-) input terminal of Norton operational amplifier circuit 60 of commutation circuit 23~ As will be brought out later is this speciica-tion, the system o~ this invention operates to sustain rotor 8 rotation after the initiation of rotor 8 rota-tion from standstill.
From the foregoing description, it is appar-ent that start circuit 20 includes a monostable multi-vibrator circuit that produces a first electrical output signal pulse of a predetermined duration a~
established by the RC time constant of timing capacitor 28 and resistor 29 upon the application of supply potential and a capacitor 44 and a resistor 45 that , produces a second opposite polarity electrical output signal pulse of a predetermined duration as established by the RC time constant of capacitor 44 and resistor 4S upon the termination of the first output signal pulse. In a manner to be later explained, start cir-cuit 20 is disabled while rotor 8 rotation is sustained by the operation oE the system of this invention.
While rotor 8 is rotating, the magnetic field of rot~ting rotor 8 induces alternating current poten-tial waveforms in stator phase windings A, B and c i97 that are phase displaced ~rom each other by 120 elec-trical degrees and are superimposed upon the direct current potential level of the supply potential souxce as illustrated by the curve of Figure 2A wherein the supply potential source potential level is referenced by the notation B+. These induced potential waveforms are of a frequency and amplitude directly proportional to the rotational speed of rotor 8. However, in a manner to be later explained, the NPN transistor Darlington pairs 15, 17 and 19 are conductive part of the time and not conductive part of the time. While NP~ transistor Darlington pair 15 is not conductive, the potential level upon junction 63 is substantially egual to the sum of the alternating current potential waveform induced in stator phase winding A by the rotor 8 magnetic field and the potential level of the supply potential source and while ~P~ transistor Darlington pair 15 is conductive, the potential level upon junc-tion 63 is substantially ground, as illustrated by the curve of Figure 2B. While ~P~ transistor Darlington pair 17 is not conductive, the potential level upon junction 64 is substantially equal to the sum of the alternating current potential waveform induced in stator phase winding B by the rotor 8 magnetic field and the potential level of the supply potential source and wh.ile NPN transistor Darlington pair 17 i5 conductive, the potential level upon junction 64 is substantially 1~3~69 ~
ground, as illustrated by the curve of Figure 2C.
While NP~ transis-tor Darlington pair 19 is not conduc-tive, the potential level upon junction 65 is substan-tia;ly egual to the sum of the alternating current potential waveform induced in stator phase winding C
by the rotor 8 ma~netic field and the potential level of the supply potential source and while ~PN transistor Darlington pair 19 is conductive, the potential level upon junction 65 i5 substantially ground, as illustra-ted ~y the curve of Figure 2D.
Commutation of ~PN transistor Darlington pairs 15, 17 and 19 is achieved by sensing the poten-tial level of the stator phase windings A, B and C.
This commutation is effected by commutation circuits 21, 22 and 23 that are responsive to the phase dis-placed potential waveforms that are induced in stator phase windings A, B and C by the rotating magnetic field of rotor 8. The potential level of stator phase winding A appears upon junction 63 and is filtered by resistor 67, diode 68, capacitor 69 and diode 70. The potential level of stator phase winding ~ appears upon junction 64 and is filtered by resistor 71, diode 72, capacitor 73 and diode 74~ The potential level o.
stator phase winding C appears upon junction 65 and is filtered by resistor 75, diode 76, capacitor 77 and diode 78. In addition, it is the function of diodes 70, 74 and 78 to prevent the potential upon respecti~e ~13~6g7 junctions 81, 82 and 83 from increasing to a potential level greater than one diode drop above the level of the supply potential. The combination of resistor 67, diode 68 and capacitor 69 functions as a voltage peak follower circuit whereby the charge upon capacitor 69 follows the change of potential level upon junction 63;
the combination of resistor 71, diode 72 and capacitor 73 functions as a voltage peak follower circuit whereby the charge upon capacitor 73 follows the change of potential level upon junction 64; and the combination of resistor 75, diode 76 and capacitor 77 functions as a voltage peak follower circuit whereby the charge upon capacitor 77 follows the change of potential level upon junction 65.
In each of the curves of Figure 2, the supply potential level is referenced by the notation B+.
Referring to Figure 2, upon the initiation at time To of rotor 8 rotation in a counterclocXwise direction at a speed greater than the minimum commutation speed in a manner hereinabove explained with reference to start circuit 20, the potential level upon each o junctions 63 and 64 is substantially ground, as illustrated by respective curves 2B and 2C, for the reason that both NPN transistor Darlington pairs 15 and 17 are conduc-tive through the current carrying elements thereof andthe potential upon junction 65 is of substantially supply potential for the reason that transistor Darling-ton pair 19 is not conductive through the current 1~
1~66'~7 carrying elements thereof, as illustrated by curve 2D.
As rotor 8 rotates between times To and Tl o~
Figure 2, the signal upon each of junctions 63 and 64 remains at substantially ground potential, as illustrated by respective curves 2B and 2C, and the alternating cur-rent potential waveform induced in phase winding C by the magnetic field of rotating rotor 8 increases in a positive going direction from the supply potential level and appears upon junction 65, as illustrated by curve 2~.
This increasing potential upon junction 65 charges capacitor 86 o~ commutation circuit 21 through lead 84 and resistor 85. When, at time Tl, capacitor 86 has charged to a direct current potential level o~ a magni-tude sufficient to supply more current through input resistor 87 to the minus (-) input terminal of ~orton operational ampli~ier circuit 40 than is supplied to the plus (+) input terminal thereof through input resistor 88 from the positive polarity output terminal o~ the supply potential source, Norton operational amplifier circuit 40 is abruptly triggered to the condition in which the output signal thereof upon junction 51 is of substantially ground potential. With a substantially ground potential signal upon junction 51, NP~ transistor Darlington pair 15 is triggered not conductive to inter-rupt the previously described stator phase ~inding ~energizing circuit. Upon the interruption of this ener-gizing circuit, the alternating currenk potential wave-form induced in phase winding ~ by ~he magnetic field of 20rotating rotor 8 is superimposed upon the direct current supply potential and appears upon ]unction 63, as illus-trated by the curve 2B.
As rotor 8 rotates between times Tl and T2, the alternating current potential waveform induced in phase winding A by the magnetic field of rota-ting rotor 8 that appears upon junction 63 passes through B+ from a negative to a positive polarity direction and further increases in a positive going direction toward the maxi-mum positive polarity level, as illustrated by curve 2B;the signal upon junction 6~ remains at substantially ground potential as ~P~ transistor Darlington pair 17 is still conductive, as illustrated by curve 2C; and the alternating current potential waveform induced i.n phase winding C by the magnetic field of rota-tiny rotor 8 that appears upon junction 65 increases to and passes through the maximum positive polarity level and decreases in a negative going direction through B~, as illustrated by eurve 2D. The potential waveform upon ~unetion 65 is followed by a corresponding eharge upon capacitor 77.
When~ at time T2, the charge upon capacitor 77 has decreased to a direct current potential level of a magnitude that is insufficient to supply more eurrent through input resistor 97 to the minus (-) input terminal of ~orton operational ampli-Eier circuit 60 than is sup-plled to the plus (+) input terminal thereof through input resistor 98 from the positive polarity output terminal of the supply potential source~ Norton 13 3~697 operational amplifier eircuit 60 is abruptly triggered to the condition in which the output signal thereo:E upon junetion 53 is o-f a positive polarity potential level substantially equal to the supply potential level. This positive polari'cy potential signal upon junction 53 sup-plies base-emitter drive current throua,h resistor 99 to NPN transistor Darlington pair 19, including an e~nitter resistor 59, to trigger this transistor Darlington pai.r eonductive throu~h the current earrying element~ thereo~
~0 to eomplete the previously described stator phase winding C energizing eireuit and the potential signal upon june-tion 65 goes to substantially ground potential, as illustrated by eurve 2D.
As rotor 8 rotates between times T~ and T3, the alternating eurrent potential waveform induced in phase winding A by the magnetie field o~ rotating rotor 8 that appears upon junetion 63 continues to increase in a posi-tive going direction toward the maximum positive polarity level, as illustrated by eurve 2B; the signal upon junc-tion 64 remains at substantially ground potential as NP~transistor Darlington pair 17 is still eonductive, as illustrated by curve 2C; and the signal upon junction 65 remains at substantially ground potential as NPN transis-tor Darlington pair 19 is still conductive, as illustrated by eurve 2D. The increasing potential level upon junction 63 hetween times T2 and T3 charges capaeitor 91 o~ co~mu-tation eircuit 22 through lead 89 and resistor 90. When, at time T3, eapacitor 91 has eha.rged -to a dixect eurrent ~13~7 potential level oE a magnitude suLficient to supply more current through input resistor 92 to -the minus (-) input terminal of ~orton operational amplifier circuit 50 than is supplied to the plus (~) input terminal thereo~
5 through input resistor 93 fxom the positive polarity output terminal of the supply potential source, ~orton operational amplifier circuit 50 is abruptly triggered to the condition in which the output signal thereof upon junction 52 is o substantially ground potential. With a substantially ground potential signal upon junction 52, NPN transistor Darlington pair 17 is triggered not con-ductive to interrupt the previously described stator phase winding B energizing circuit and capacltor 86 of commutation circuit 21 discharges through diode 94, lead 96 and the emitter-collector electrodes of PNP
transistor 95. Upon the interruption of the stator phase winding B energizing circuit, the alternating current potential wave~orm induced in phase winding B
by the magnetic field of rotating rotor 8 is super- , imposed upon the direct current supply potential and appears upon junction 64, as illustrated by curve 2C.
As rotor 8 rotates between times T3 and Ta~
the alternating current potential waveform induced in phase winding B by the magnetic field of rotating rotor 8 that appears upon junction 64 passes through B+ from a negative to a positive polarity direction and further increases in a positive going direction toward the maxi-mum pos:tive polaxity level, as illustrated by curve 2C, 113~ 7 the signal upon junction 55 rema:Lns at substantially ground potential as NPN transis-tor Darlington pair 19 is still conductive, as illustrated by curve 2D; and the alternating current potential waveform induced in phase winding A by the magnetic ~ield of rotating rotor 8 that appears upon junction 63 increases to and passes through the maximum positive polarity level and de-creases in a negative going direction through B+, as illustrated by curve 2B. The potential waveform upon junction 63 is followed by a corresponding charge upon capacitor 69. When, at time T4, the charge upon capacitor 69 has decreased to a direct current poten-tial level of a magnitude that is insufficient to supply more current through input resistor 110 to the minus (-) input terminal of Norton operational amplifier circuit 40 thal; is suppl'ed to the plus (~) input terminal thereof through input resistor 88 from the positive polarity output terminal o~ the supply potential source, Norton operational amplifier circuit 40 is abruptly triggered to the condition in which the output signal thereof upon junction 51 is o~ a positive polarity potential level substantially equal to the supply potential level. This positive polarity potential signal upon junction 51 supplies base-emitter drive current through resistor 54 to NPN transistor Darling-ton pair 15 to trigger this transistor Darlington pair conductive through the current carrying elements thercof to complete the prcviousl~ described stator phase ~3~6~ !7 winding ~ energizing circuit and the potential signal upon junction 63 goes to substantially c~rourld poten-tial, as illustrated by curve 2B.
As rotor 8 rotates between times T4 and T5, the alternating current potential waveform induced in phase winding B by the magnetic field of rotating rotor 8 that appears upon junction 64 continues to increase in a positive going direction toward the maximum posi-tive polarity level, as illustrated by curve 2C the signal upon junction 65 remains at substantially ground potential as ~P~ transistor Darlington pair 19 is still conductive, as il.lustrated by curve 2D; and the signal upon junction 63 remains at substantially ground poten-tial as ~PN transistor Darlington pair 15 is still conductive, as illustrated by curve 2B. The increas-ing potential level u.pon junction 64 between times T4 and T5 charges capacitor 100 of commutation circuit 23 through lead 101 and resistor 102. When, at time T5, capacitor 100 has charged to a direct current potential level of a magnitude sufficient to supply more current through input resistor 103 to the minus (-) input terminal of ~orton operational amplifier circuit 60 than is supplied to the plus (+) input terminal thereof through input resistor 9~ from the positive polarity output terminal of the supply potential source, Norton operational amplifier circuit 60 is abruptly triggered to the con~ition in ~hich the output signal thereo-f upon junction 53 is of substantially ground potential.
~3~ 7' With a substantially ground potential signal upon junction 53, NP~ transistor Darlington pair 19 is triggered not conductive to interrupt the previously described stator phase winding C energizing circuit and capacitor 91 of commutation circuit 22 discharges through diode 104, lead 105 and the emi-tter-collector electrodes of PNP transistor 106. Upon the interrup-tion o:E the stator phase winding C energizing circuit, -the alternating current potential waveEorm induced in phase winding C by the magnetic field o~ rotatiny rotor 8 is superimposed upon the direct current supply poten-tial and appears upon junction 6S, as illustra-ted by curve 2D.
As rotor 8 rotates between times T5 and T6, the alternating current potential waveiorm induced in phase winding C by the magnetic ~.ield of rotating -otor 8 that appears upon junction 65 passes through B+ from a negative to a positive polarity direction and further increases in a positive going direction toward the maxi- , mum positive polarity level, as illustrated by curve 2D;
the signal upon junction 63 remains at substantially ground potential as ~P~ transistor Darlington pair 15 is still conductive, as illustrated by curve 2B, and the alternating current poten-tial waveEorm induced in phase winding B by the magnetic field o~ rotati.ng rotor 8 that appears upon junction 64 inc:reases to and passe.s through the maxlmum positive polarity level and ae-creases in a neyative going direction throuyh B-~, as 113~69~7 illustrated by curve 2C. The potential waveform upon junction 64 is follo-~ed by a corresponding ch~rge upon capacitor 73. When, at time T6, the charge upon capaci~
tor 73 has decreased to a direct current potential level oE a magnitude that is insufficient to supply more current through input resistor 121 to the minus (-) input terminal of ~orton operational amplifier circuit 50 than is supplied to the plus (~) input terminal thereof through input resiscor 93 from the positive polarity outpu-t terminal of the supply potential source, Norton operational ampli~ier circuit 50 is abruptly triggered to the condition in which the output signal thereof upon junction 52 is o~ a positive polarity potential level substantially equal to the supply potential level. This positive polarity potential signal upon junction 52 supplies base-emitter drive current through resistor 57 to ~P~ transistor Darling-ton pair 17 to trigger this transistor Darlington pair conductive through the current carrying elements thereof to complete the previously described stator phase winding B energizing circuit and the potential signal upon junction 64 goes to substantially qround potential, as illustrated by curve 2C.
As rotor 8 rotates between times T6 and T7, -the alternating current potential waveform induced in phase winding C by che magnetic field of rotating rotor 8 that appears upon juncti.on 65 continues to increase in a positive going direct;on toward the maximum 1~3~ 7 positive polarity level, as illustrated by curve 2D
the signal upon junction 63 remains at substantially ground potential as NPN transistor Darlington pai,r 15 is still conductive, as illustrated by curve 2B; and the signal upon junction 64 remains at substantially ground potent.ial as NPN transistor Darlington pair 17 is still conductive, as illustrated by curve 2C. The increasing potential level upon junction 65 between times T6 and T7 charges capacitor 86 of commutation circuit 21 through lead 84 and resistor 85. ~hen, at time T7, capacitor ~6 has charged to a direct current potential level o a magnitude sufficient to supply more current through input resistor 87 to the minus (-) input terminal of Norton operational amplifier circuit 40 than is supplied to the plus (~) i.nput terminal thereof through input resistor 8~ ~rom the positive polarity output terminal of the supply potential source, Norton operational amplifier circuit 40 is abruptly triggered to the condition in which the output signal thereof upon junction 51 is of substanti-ally ground potential. With a substantially ground potential signal upon junction 51, ~PN transistor Darlington pair 15 is triggered not conductive to interrupt the previously described stator phase winding A energizing circuit ana capacitor 100 of comrnutation circuit 23 discharges through diode 112, lead 115 and the ernit-ter-collector electrodes of PNP
1~3~ 7 trans.istor 120. Upon the interruption of the stator phase winding A energizing circuit, the alternating current potential waveform induced in phase winding ~ by the magnetic field of rotating rotor 8 is super-imposed upon the direct current supply potential andappears upo~ junction 63, as illustrated by curve 2B.
The cycle of events just described repeats so long as the application of su~ply potential is maintained through switch lO. Referring to Figure 2, after initial rotor start from standstill and beginning with time T2, stator phase winding C, stator phase winding A and stator phase winding B
are sequentially energized in that order repeatedly.
This seauential stator phase winding energi7ation produces a rotating magnetic field in a manner well known in the art that sustains rotor rotation. For rotor rotation in the opposite direction, the sequence of stator phase winding energization would be reversed by reversing the connection of the terminal end opposite node ~ of any two of leads 14, 16 and 18.
It is apparent from the foregoing descrip-tion that each of commutation circuits 21, 22 and 23 ~.~36~i97 corresponds to a respective stator phase winding A, B
and C and that these commutation circuits are responsive to the alternating current phase displaced potential waveforms induced in stator phase windings A, ~ and C
for sustaining rotor 8 rotation after initial start from standstill by sequentially completing and later interrupting the respective individual stator phase winding energizing circuits that results in a rotating magnetic field.
Each of commutation circuits 21, 22 and 23 includes a Norton operational amplifier circuit and an ~PM transistor Darlington pair. Each combination of Norton operational amplifier circuit 40 and NP~ tran-sistor Darlington pair 15 of commutation circuit 21, ~orton operation amplifier circuit 5~ and NPN transis-tor Darlington pair 17 of commutation circuit 22 and Norton operational amplifier circuit 60 and ~P~ tran-sistor Darlington pair l9 is an electrically operable switching arrangement that is capable of being operated ~, to first and second operating conditions in response to the application thereto of electrical signals of a value less than and greater than a predetermined magni-tude and is effective to complete and interrupt the stator phase winding to which each corresponds when in the first and second operating conditions, respectively.
The switch point of each is determined by the supply potential level and the ohmic value o respective input resistors 88, 93 and 98 that determines the predeter-1~3~697 mined magnitude that the applied electrical signals must be less than and greater than. When the electri-cal signal applied to these swi.tching arrangements is of a level less than the predetermined magnitude, the applied electrical signal supplies less current to the minus (-) input terminal of the ~orton operational amplifier circuit than is supplied to the plus (~) input terminal, consequently, the switching arrangement is triggered to the operating condition in which ~he stator phase winding energizing circuit for the stator phase winding to which it corresponds is completed and when the applied electrical signal is of a level greater than the predetermined magn.itude, the applied signal supplies more current into the m.inus (-) input terminal of the Norton operational amplifier circuit than is supplied to the plus (~) input terminal, con-se~uently, the switching arrangement is triggered to the operating condition in which the stator phase winding energizing circuit for the stator phase winding to which it corresponds is interrupted. The potential waveform induced in stator phase winding A is applied to the minus (-~ input terminal of Norton operational amplifier circuit 40 of the corresponding switching arrangement through resistor 67, diode 68, capacitor 25 69 and resistor 110. The potential waveform induced in stator phase winding B is applied to the minus (-) input terminal of Norton operational amplifier circuit 50 of the corresponding switching arrangement through 69~
resistor 71, diode 72, capacitor 73 and resistor 121.
The potential waveform induced in stator phase winding C is applied to the minus ~-) input terminal of ~orton operational amplifier circuit 60 of the corresponding switching arrangement through resistor 75, diode 76, capacitox 77 and resistor 97. The potential waveform induced in stator phase winding A is applied to the minus (-) input terminal of Norton operational ampli-fier circuit 50 of the switching arrangement that corresponds to another stator pha.se winding B through lead 89, resistor 90, capacitor 91 and resistor 92.
The potential waveform induced in stator phase winding B is applied to the minus (-) input terminal of ~orton operational amplifier circuit 6Q of the switching arrangement that corresponds to another stator phase winding C through lead lOl, resistor 102, capacitor 100 and resistor 103. The potential waveform induced in stator phase winding C is applied to the minus ~-) input terminal of Norton operational amplifier circuit 40 of the switching arrangement that corresponds to another stator phase winding A through lead 84, resistor 85, capacitor 86 and resistor 87.
The combination of resistor 85 and capacitor 86 of commutation circuit 21 delays the application of the potential waveform induced in stator phase winding C to the minus (-) input terminal of Norton operational amplifier circuit 40 of commutation circuit 21: the combination of resistor 90 and capacitor 91 delays the 1~3~6~7 application of the potential waveform induced in stator phase winding ~ to the minus (-) input terrninal of Norton opera~ional amplifier circuit 50 of commutation circuit 22 and the cor~ination of resistor 102 and capacitor 100 delays the application of the potential waveform induced in stator phase winding B to the minus (-) input terminal of ~orton operational amplifier cir-cuit 60 of commutation circuit 23. By changing the delay introduced by these circuits, the period o con-duction of each of ~P~ transistor Darlington pairs 15,17 and 19 may be selected. As a result of the delay introduced by these resistor-capacitor cor~inations, each stator phase winding is deenergized at a time after the next stator phase winding in the seguence is ener-1~ gized as determined by this delay. These resistor-capacitor co~binations are so designed that each of capacitors 86, 91 and 100 charge through respective resistors 85, 90 and 102 at a xate that increases with the amplitude of the potential waveform induced in the respective stator phase winding to which each is con-nected. Conseguently, these resistor-capacitor cor~inations introduce a variable delay that is deter-mined by the motor speed, the lower the motor speed, the longer the delay period, and vice versa.
In a manner hereinabove explained in detail, while the drive system o this invention is sustaining rotor 8 rotation in response to the phase displaced potential waveforms induced in stator phase windings A, 1~36697 B and C, Norton operational amplifier circuit 60 is triggered to the condition in which the output signal thereof upon junction 53 is of a positive polarit~ and o a magnitude substantially equal to supply potential during each negative half cycle of the potential wave-form induced in stator phase winding C and is triggered to the condition in which the output signal thereor is substantially ground potential during each positive half cycle of the potential waveform induced in stator phase winding C. This signal is applied through lead 122, resistor 123 and coupling capacitor 124 to the base electrode of ~P~ transistor 32. While this signal is of a positive polarity, base-emitter drive current is supplied thereby to ~P~ transistor 32 to trigger this device conductive through the collector-emitter elec-trodes to provide a discharge path for capaci~or 33 during each negative half cycle of the potential waveform induced in stator phase winding C. While this signal is of ground potential, coupling capacitor 124 discharges through diode 125. The RC time constant of capacitor 33 and charging resistor 34 is so arranged that capacitor 33 does not charge to a sufficient potential level to efect the triggering of Norton operational amplifier circuit 25 between successive negative polarity half cycles of the potential waveform induced in phase windingC. Therefore, 50 long as the system of this invention is sustaining roto.r rotation in response to the potential wavefo~ns induced in the stator phase windings, start ~3ti~97 circuit 20 is maintained disabled. Zener diodes 126, 127 and 12B protect respective ~P~ transistor DarlingtOn pairs against possibly destructive high voltage transi-ents.
~hile a preferred embodiment o~ the present invention has been shown and described, it will be obvious to those skilled in the art that various modifi-cations and substitu~ions may be made without departing from the spirit of the invention which i5 to be limited only within the scope o the appended claims.
Claims (5)
1. A commutatorless direct current motor drive system for use with direct current motors of the type having a stator including a plurality of phase windings that may be individually energized by an applied supply potential through respective individual stator phase winding energizing circuits arranged for electrical connection across an external supply poten-tial source and a permanent magnet rotor arranged to be rotated in magnetic coupling relationship with the stator phase windings whereby upon rotor rotation, the rotor magnetic field induces alternating current potential waveforms in the stator phase windings that are phase displaced from each other by the number of electrical degrees determined by the number of stator phases, comprising:
means for initiating rotor rotation from standstill whereby said phase displaced potential waveforms are initially induced in said stator phase windings;
means connected to said external supply potential source for producing a reference signal; and means responsive to said phase displaced potential waveforms induced in said stator phase windings for sustaining rotor rotation by sequen-tially completing and later interrupting said respective individual stator phase winding ener-gizing circuits, said means including switching means connected to each said stator phase winding for effecting the completion of the said stator phase winding energizing circuit for the said stator phase winding to which it is connected in response to each negative going portion of the said potential waveform induced in that stator phase winding attaining a level that has a predetermined relationship to said ref-erence signal and for effecting the interruption of this energizing circuit in response to a predetermined potential level of the said potential waveform in-duced in another one of said stator phase windings whereby, after initiation of rotor rotation from standstill, said stator phase windings may be sequen-tially energized and later deenergized in response to said phase displaced potential waveforms induced in said stator phase windings to produce a rotating magnetic field that sustains rotor rotation.
means for initiating rotor rotation from standstill whereby said phase displaced potential waveforms are initially induced in said stator phase windings;
means connected to said external supply potential source for producing a reference signal; and means responsive to said phase displaced potential waveforms induced in said stator phase windings for sustaining rotor rotation by sequen-tially completing and later interrupting said respective individual stator phase winding ener-gizing circuits, said means including switching means connected to each said stator phase winding for effecting the completion of the said stator phase winding energizing circuit for the said stator phase winding to which it is connected in response to each negative going portion of the said potential waveform induced in that stator phase winding attaining a level that has a predetermined relationship to said ref-erence signal and for effecting the interruption of this energizing circuit in response to a predetermined potential level of the said potential waveform in-duced in another one of said stator phase windings whereby, after initiation of rotor rotation from standstill, said stator phase windings may be sequen-tially energized and later deenergized in response to said phase displaced potential waveforms induced in said stator phase windings to produce a rotating magnetic field that sustains rotor rotation.
2. A commutatorless direct current motor drive system for use with direct current motors of the type having a stator including a plurality of phase windings that may be individually energized by an applied supply potential through respective individual stator phase winding energizing circuits arranged for electrical connection across an ex-ternal supply potential source and a permanent magnet rotor arranged to be rotated in magnetic coupling relationship with the stator phase windings whereby upon rotor rotation, the rotor magnetic field in-duces alternating current potential waveforms in the stator phase windings that are phase displaced from each other by the number of electrical degrees determined by the number of stator phases comprising:
means for initiating rotor rotation from standstill whereby said phase displaced potential waveforms are initially induced in said stator phase windings;
means connected to said external supply potential source for producing a reference signal;
an electrically operable switching arrange-ment connected to each of said stator phase windings that is capable of being operated to first and second operating conditions in response to the application thereto of electrical signals of a value less than and greater than that of said reference signal and being effective to complete and interrupt the said stator phase winding energizing circuit for the said stator phase winding to which it is connected when in said first and second operating conditions, re-spectively;
means for applying the said potential wave-form induced in each of said stator phase windings to the said switching arrangement connected thereto for actuating the said switching arrangement to the operating condition in which the completion of the said stator phase winding energizing circuit for the said stator phase winding to which said switching arrangement is connected is effected during each negative going portion of the induced potential wave-form; and means for applying the said potential wave-form induced in each of said stator phase windings to a said switching arrangement that is connected to another said stator phase winding for actuating the said switching arrangement to which it is applied to the operating condition in which the interruption of the said stator phase winding energizing circuit for the stator phase winding to which said switching arrangement is connected is effected during each positive going portion of the induced potential wave-form whereby, after initiation of rotor rotation from standstill, said stator phase windings may be sequen-tially energized and later deenergized in response to said phase displaced potential waveforms induced in said stator phase windings to produce a rotating magnetic field that sustains rotor rotation.
means for initiating rotor rotation from standstill whereby said phase displaced potential waveforms are initially induced in said stator phase windings;
means connected to said external supply potential source for producing a reference signal;
an electrically operable switching arrange-ment connected to each of said stator phase windings that is capable of being operated to first and second operating conditions in response to the application thereto of electrical signals of a value less than and greater than that of said reference signal and being effective to complete and interrupt the said stator phase winding energizing circuit for the said stator phase winding to which it is connected when in said first and second operating conditions, re-spectively;
means for applying the said potential wave-form induced in each of said stator phase windings to the said switching arrangement connected thereto for actuating the said switching arrangement to the operating condition in which the completion of the said stator phase winding energizing circuit for the said stator phase winding to which said switching arrangement is connected is effected during each negative going portion of the induced potential wave-form; and means for applying the said potential wave-form induced in each of said stator phase windings to a said switching arrangement that is connected to another said stator phase winding for actuating the said switching arrangement to which it is applied to the operating condition in which the interruption of the said stator phase winding energizing circuit for the stator phase winding to which said switching arrangement is connected is effected during each positive going portion of the induced potential wave-form whereby, after initiation of rotor rotation from standstill, said stator phase windings may be sequen-tially energized and later deenergized in response to said phase displaced potential waveforms induced in said stator phase windings to produce a rotating magnetic field that sustains rotor rotation.
3. A commutatorless direct current motor drive system for use with direct current motors of the type having a stator including a plurality of phase windings that may be individually energized by an applied supply potential through respective individual stator phase winding energizing circuits arranged for electrical connection across an ex-ternal supply potential source and a permanent magnet rotor arranged to be rotated in magnetic coupling relationship with the stator phase windings whereby upon rotor rotation, the rotor magnetic field induces alternating current potential waveforms in the stator phase windings that are phase displaced from each other by the number of electrical degrees determined by the number of stator phases comprising:
means for initiating rotor rotation from standstill whereby said phase displaced potential waveforms are initially induced in said stator phase windings;
means connected to said external supply potential source for producing a reference signal;
an electrically operable switching arrange-ment connected to each of said stator phase windings that is capable of being operated to first and second operating conditions in response to the appli-cation thereto of respective electrical signals of a value less than and greater than that of said reference signal and being effective to complete and interrupt the said stator phase winding ener-gizing circuit for the said stator phase winding to which it is connected when in said first and second operating conditions, respectively;
means for applying the said potential wave-form induced in each of said stator phase windings to the said switching arrangement connected thereto for actuating the said switching arrangement to the operating condition in which the completion of the said stator phase winding energizing circuit for the said stator phase winding to which said switching arrangement is connected is effected during each negative going portion of the induced potential wave-form; and means including variable delay circuit means for applying the said potential waveform induced in each of said stator phase windings to a said switching arrangement that is connected to another said stator phase winding for actuating the said switching arrange-ment to which it is applied to the operating condition in which the interruption of the said stator phase winding energizing circuit for the stator phase wind-ing to which said switching arrangement is connected is effected during each positive going portion of the induced potential waveform whereby, after initiation of rotor rotation from standstill, said stator phase windings may be sequentially energized and later deenergized in response to said phase displaced potential waveforms induced in said stator phase windings to produce a rotating magnetic field that sustains rotor rotation.
means for initiating rotor rotation from standstill whereby said phase displaced potential waveforms are initially induced in said stator phase windings;
means connected to said external supply potential source for producing a reference signal;
an electrically operable switching arrange-ment connected to each of said stator phase windings that is capable of being operated to first and second operating conditions in response to the appli-cation thereto of respective electrical signals of a value less than and greater than that of said reference signal and being effective to complete and interrupt the said stator phase winding ener-gizing circuit for the said stator phase winding to which it is connected when in said first and second operating conditions, respectively;
means for applying the said potential wave-form induced in each of said stator phase windings to the said switching arrangement connected thereto for actuating the said switching arrangement to the operating condition in which the completion of the said stator phase winding energizing circuit for the said stator phase winding to which said switching arrangement is connected is effected during each negative going portion of the induced potential wave-form; and means including variable delay circuit means for applying the said potential waveform induced in each of said stator phase windings to a said switching arrangement that is connected to another said stator phase winding for actuating the said switching arrange-ment to which it is applied to the operating condition in which the interruption of the said stator phase winding energizing circuit for the stator phase wind-ing to which said switching arrangement is connected is effected during each positive going portion of the induced potential waveform whereby, after initiation of rotor rotation from standstill, said stator phase windings may be sequentially energized and later deenergized in response to said phase displaced potential waveforms induced in said stator phase windings to produce a rotating magnetic field that sustains rotor rotation.
4. A commutatorless direct current motor drive system for use with direct current motors of the type having a stator including a plurality of phase windings that may be individually energized by an applied supply potential through respective individual stator phase winding energizing circuits arranged for electrical connection across an external supply potential source and a permanent magnet rotor arranged to be rotated in magnetic coupling relation-ship with the stator phase windings whereby upon rotor rotation, the rotor magnetic field induces alternating current potential waveforms in the stator phase windings that are phase displaced from each other by the number of electrical degrees determined by the number of stator phases comprising:
means for initiating rotor rotation from standstill whereby said phase displaced potential waveforms are initially induced in said stator phase windings, said means including means for producing a first electrical signal pulse of a predetermined duration upon the application of supply potential and a second opposite polarity electrical signal pulse of a predetermined duration upon the termination of said first output signal pulse;
means connected to said external supply potential source for producing a reference signal;
an electrically operable switching arrange-ment connected to each of said stator phase windings that is capable of being operated to first and second operating conditions in response to the application thereto of respective electrical signals of a value less than and greater than that of said reference signal and being effective to complete and interrupt the said stator phase winding energizing circuit for the said stator phase winding to which it is con-nected when in said first and second operating conditions, respectively;
means for applying said first output signal pulse of said rotor rotation initiating means to a selected one of said switching arrangements in such a manner as to operate said switching arrangement to the operating condition in which it is effective to complete the said phase winding energizing circuit for the said phase winding to which it is connected and to each other one of said switching arrangements in such a manner as to operate these said switching arrangements to the operating condition in which each is effective to interrupt the said stator phase winding energizing circuit for the said stator phase winding to which it is connected;
means for applying said second output signal pulse of said rotor rotation initiating means to another selected one of said switching arrangements in such a manner as to operate said switching arrange-ment to the operating condition in which it is effec-tive to complete the said phase winding energizing circuit for the said phase winding to which it is connected to initiate rotor rotation;
means for applying the said potential wave-form induced in each of said stator phase windings to the said switching arrangement connected thereto for actuating the said switching arrangement to the operating condition in which the completion of the said stator phase winding energizing circuit for the said stator phase winding to which said switching arrangement is connected is effected during each negative going portion of the induced potential wave-form;
means for applying the said potential wave-form induced in each of said stator phase windings to a said switching arrangement that is connected to another said stator phase winding for actuating the said switching arrangement to which it is applied to the operating condition in which the interruption of the said stator phase winding energizing circuit for the stator phase winding to which said switching arrangement is connected is effected during each positive going portion of the induced potential wave-form whereby, after initiation of rotor rotation from standstill, said stator phase windings may be sequentially energized and later deenergized in response to said phase displaced potential waveforms induced in said stator phase windings to produce a rotating magnetic field that sustains rotor rotation;
and means for disabling said rotor rotation initiating means while said rotor is rotating in response to said phase displaced potential waveforms.
means for initiating rotor rotation from standstill whereby said phase displaced potential waveforms are initially induced in said stator phase windings, said means including means for producing a first electrical signal pulse of a predetermined duration upon the application of supply potential and a second opposite polarity electrical signal pulse of a predetermined duration upon the termination of said first output signal pulse;
means connected to said external supply potential source for producing a reference signal;
an electrically operable switching arrange-ment connected to each of said stator phase windings that is capable of being operated to first and second operating conditions in response to the application thereto of respective electrical signals of a value less than and greater than that of said reference signal and being effective to complete and interrupt the said stator phase winding energizing circuit for the said stator phase winding to which it is con-nected when in said first and second operating conditions, respectively;
means for applying said first output signal pulse of said rotor rotation initiating means to a selected one of said switching arrangements in such a manner as to operate said switching arrangement to the operating condition in which it is effective to complete the said phase winding energizing circuit for the said phase winding to which it is connected and to each other one of said switching arrangements in such a manner as to operate these said switching arrangements to the operating condition in which each is effective to interrupt the said stator phase winding energizing circuit for the said stator phase winding to which it is connected;
means for applying said second output signal pulse of said rotor rotation initiating means to another selected one of said switching arrangements in such a manner as to operate said switching arrange-ment to the operating condition in which it is effec-tive to complete the said phase winding energizing circuit for the said phase winding to which it is connected to initiate rotor rotation;
means for applying the said potential wave-form induced in each of said stator phase windings to the said switching arrangement connected thereto for actuating the said switching arrangement to the operating condition in which the completion of the said stator phase winding energizing circuit for the said stator phase winding to which said switching arrangement is connected is effected during each negative going portion of the induced potential wave-form;
means for applying the said potential wave-form induced in each of said stator phase windings to a said switching arrangement that is connected to another said stator phase winding for actuating the said switching arrangement to which it is applied to the operating condition in which the interruption of the said stator phase winding energizing circuit for the stator phase winding to which said switching arrangement is connected is effected during each positive going portion of the induced potential wave-form whereby, after initiation of rotor rotation from standstill, said stator phase windings may be sequentially energized and later deenergized in response to said phase displaced potential waveforms induced in said stator phase windings to produce a rotating magnetic field that sustains rotor rotation;
and means for disabling said rotor rotation initiating means while said rotor is rotating in response to said phase displaced potential waveforms.
5. A commutatorless direct current motor drive system for use with direct current motors of the type having a stator including a plurality of phase windings that may be individually energized by an applied supply potential through respective individual stator phase winding energizing circuits arranged for electrical connection across an external supply potential source and a permanent magnet rotor arranged to be rotated in magnetic coupling relation-ship with the stator phase windings whereby upon rotor rotation, the rotor magnetic field induces alternating current potential waveforms in the stator phase windings that are phase displaced from each other by the number of electrical degrees determined by the number of stator phases comprising:
means for initiating rotor rotation from standstill whereby said phase displaced potential waveforms are initially induced in said stator phase windings;
means connected to said external supply potential source for producing a reference signal;
means responsive to said phase displaced potential waveforms induced in said stator phase windings for sustaining rotor rotation by sequen-tially completing and later interrupting said respective individual stator phase winding ener-gizing circuits, said means including switching means connected to each said stator phase winding and means for applying to the said switching means connected to any said stator phase winding both the said potential waveform induced in the said stator phase winding to which said switching means is connected and the said potential waveform induced in another said stator phase winding with said switching means being so arranged as to be operative to effect the completion of the said stator phase winding ener-gizing circuit for the said stator phase winding to which it is connected in response to each negative going portion of the said potential waveform induced in that stator phase winding attaining a level that has a predetermined relationship to said reference signal and to effect the interruption of this ener-gizing circuit in response to a predetermined potential level during each positive going portion of the said potential waveform induced in said another said stator phase winding whereby, after initiation of rotor rotation from standstill, said stator phase windings may be sequentially energized and later deenergized in response to said phase displaced potential waveforms induced in said stator phase windings to produce a rotating magnetic field that sustains rotor rotation; and means for disabling said rotor rotation initiating means while said rotor is rotating in response to said phase displaced potential wave-forms.
means for initiating rotor rotation from standstill whereby said phase displaced potential waveforms are initially induced in said stator phase windings;
means connected to said external supply potential source for producing a reference signal;
means responsive to said phase displaced potential waveforms induced in said stator phase windings for sustaining rotor rotation by sequen-tially completing and later interrupting said respective individual stator phase winding ener-gizing circuits, said means including switching means connected to each said stator phase winding and means for applying to the said switching means connected to any said stator phase winding both the said potential waveform induced in the said stator phase winding to which said switching means is connected and the said potential waveform induced in another said stator phase winding with said switching means being so arranged as to be operative to effect the completion of the said stator phase winding ener-gizing circuit for the said stator phase winding to which it is connected in response to each negative going portion of the said potential waveform induced in that stator phase winding attaining a level that has a predetermined relationship to said reference signal and to effect the interruption of this ener-gizing circuit in response to a predetermined potential level during each positive going portion of the said potential waveform induced in said another said stator phase winding whereby, after initiation of rotor rotation from standstill, said stator phase windings may be sequentially energized and later deenergized in response to said phase displaced potential waveforms induced in said stator phase windings to produce a rotating magnetic field that sustains rotor rotation; and means for disabling said rotor rotation initiating means while said rotor is rotating in response to said phase displaced potential wave-forms.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/029,312 US4262236A (en) | 1979-04-11 | 1979-04-11 | Commutatorless direct current motor drive system |
| US029,312 | 1979-04-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1136697A true CA1136697A (en) | 1982-11-30 |
Family
ID=21848384
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000344905A Expired CA1136697A (en) | 1979-04-11 | 1980-02-01 | Commutatorless direct current motor drive system |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4262236A (en) |
| AU (1) | AU534956B2 (en) |
| CA (1) | CA1136697A (en) |
| DE (1) | DE3013550A1 (en) |
| FR (1) | FR2454217A1 (en) |
| GB (1) | GB2047027B (en) |
Families Citing this family (28)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4262237A (en) * | 1979-06-08 | 1981-04-14 | General Motors Corporation | Commutatorless direct current motor drive system |
| US4394610A (en) * | 1981-08-07 | 1983-07-19 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Adaptive reference voltage generator for firing angle control of line-commutated inverters |
| US4403177A (en) * | 1981-08-17 | 1983-09-06 | Motorola, Inc. | Brushless three phase direct current motor control circuit |
| JPS58172994A (en) * | 1982-04-02 | 1983-10-11 | Sony Corp | Brushless motor |
| US4495450A (en) * | 1982-12-29 | 1985-01-22 | Sanyo Electric Co., Ltd. | Control device for brushless motor |
| US4532461A (en) * | 1983-11-01 | 1985-07-30 | Kollmorgen Technologies Corporation | Rotor position sensor error detection |
| DE3345554A1 (en) * | 1983-12-16 | 1985-08-29 | Teldix Gmbh, 6900 Heidelberg | DC motor without a commutator, for driving an optical deflector |
| US4588933A (en) * | 1984-09-13 | 1986-05-13 | Motorola, Inc. | Brushless direct current motor control system with protection circuitry |
| US4928042A (en) * | 1986-03-22 | 1990-05-22 | Robert Bosch Gmbh | Circuit arrangement for operating a multi-phase synchronous motor on a direct-voltage system |
| US4678973A (en) * | 1986-10-07 | 1987-07-07 | General Motors Corporation | Sensorless starting control for a brushless DC motor |
| US4922169A (en) * | 1988-10-04 | 1990-05-01 | Miniscribe Corporation | Method and apparatus for driving a brushless motor |
| BR8901539A (en) * | 1989-03-27 | 1990-10-30 | Brasil Compressores Sa | PROCESS AND ELECTRONIC CIRCUIT FOR CONTROLLING CURRENT MOTOR CONTROL WITHOUT BRUSHES |
| US5041768A (en) * | 1989-04-12 | 1991-08-20 | Motorola, Inc. | Polyphase motor control system |
| DE4090927B4 (en) * | 1989-06-01 | 2006-09-21 | Papst Licensing Gmbh & Co. Kg | Incorporated position sensor for collectorless DC motor - uses evaluation of currents fed through motor inductances |
| WO1990015473A1 (en) * | 1989-06-01 | 1990-12-13 | Papst-Motoren Gmbh & Co. Kg | Motor or position transducer |
| JPH0834711B2 (en) * | 1990-08-18 | 1996-03-29 | 日本ビクター株式会社 | Method of detecting rotor stop position in brushless DC motor without position detector |
| NZ280025A (en) * | 1990-12-19 | 1997-12-19 | Fisher & Paykel | Speed control of multiphase electronically controlled motor |
| IT1249839B (en) * | 1991-10-15 | 1995-03-28 | Magneti Marelli Spa | LINEAR CONTROL CIRCUIT IN FEEDBACK FOR A BRUSHLESS MOTOR WITH A HALF-WAVE POLYPHASE. |
| DE4213371A1 (en) * | 1992-04-23 | 1993-10-28 | Swf Auto Electric Gmbh | Commutation device for permanent-magnet brushless dc motor - has four relay windings in series with diodes and rest contacts in operation of switch banks supplying paired stator coils |
| US5367234A (en) * | 1993-08-26 | 1994-11-22 | Ditucci Joseph | Control system for sensorless brushless DC motor |
| US6297603B1 (en) * | 1994-02-28 | 2001-10-02 | Stmicroelectronics, Inc. | Circuit and method to avoid high current spikes in stator windings |
| EP0780033B1 (en) * | 1994-09-07 | 2002-01-02 | Itt Automotive Electrical Systems, Inc. | Method and apparatus for minimizing torque ripple in a dc brushless motor using phase current overlap |
| DE4435346A1 (en) * | 1994-10-01 | 1996-04-04 | Schlafhorst & Co W | Operating method for converter-fed permanently excited rotor machine with unipolar stator winding supply |
| DE4438569C2 (en) * | 1994-10-28 | 1998-09-24 | Bosch Gmbh Robert | Method and circuit arrangement for starting up an electronically commutated DC motor |
| FR2743223B1 (en) * | 1995-12-29 | 1998-03-27 | Valeo Electronique | METHOD AND DEVICE FOR CONTROLLING A SYNCHRONOUS MOTOR, ESPECIALLY A MOTOR VEHICLE |
| US6570361B1 (en) * | 1999-02-22 | 2003-05-27 | Borealis Technical Limited | Rotating induction apparatus |
| CA2598172C (en) * | 2005-02-25 | 2014-05-20 | Nova Chemicals Inc. | Lightweight compositions and articles containing such |
| JP4708483B2 (en) * | 2008-03-18 | 2011-06-22 | 株式会社デンソー | Synchronous motor drive device |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1976463A (en) * | 1933-08-02 | 1934-10-09 | Gen Electric | Electric valve converting system and exctiation apparatus therefor |
| US2644916A (en) * | 1951-02-06 | 1953-07-07 | Gen Electric | Electronic motor and commutating means therefor |
| DE1224824B (en) * | 1963-08-02 | 1966-09-15 | Siemens Ag | Circuit arrangement for brushless direct current miniature motors |
| US3569806A (en) * | 1968-10-08 | 1971-03-09 | Harrison D Brailsford | Starting arrangement for solid-state commutated motor |
| DE2012571C3 (en) * | 1970-03-17 | 1979-04-26 | Gebr. Buehler Nachfolger Gmbh, 8500 Nuernberg | Brushless DC motor |
| US3611081A (en) * | 1970-04-06 | 1971-10-05 | Sperry Rand Corp | Counter emf commutated self-starting brushless d.c. motor |
| DE2328315A1 (en) * | 1973-06-04 | 1974-12-12 | Standard Elektrik Lorenz Ag | CIRCUIT ARRANGEMENT FOR OPERATING AN ELECTRONICALLY CONTROLLED, COLLECTORLESS DC MOTOR WITH ELECTRONIC STARTER |
| JPS5633953B2 (en) * | 1973-10-30 | 1981-08-06 | ||
| DE2428718C3 (en) * | 1974-06-14 | 1979-09-06 | Teldix Gmbh, 6900 Heidelberg | Brushless DC motor |
| DE2455442A1 (en) * | 1974-11-22 | 1976-05-26 | Standard Elektrik Lorenz Ag | Automatic starting circuit for electronically-commutated DC motor - has interconnected starting transistors which are coupled to controls of switches |
| DE2517420A1 (en) * | 1975-04-19 | 1976-10-28 | Teldix Gmbh | Brushless DC motor with inductive commutation for open-end spinning - has rotor which is fitted with conducting ring or cage and which has auxiliary stator winding |
| US4162435A (en) * | 1976-10-05 | 1979-07-24 | General Electric Company | Method and apparatus for electronically commutating a direct current motor without position sensors |
-
1979
- 1979-04-11 US US06/029,312 patent/US4262236A/en not_active Expired - Lifetime
-
1980
- 1980-02-01 CA CA000344905A patent/CA1136697A/en not_active Expired
- 1980-03-27 GB GB8010261A patent/GB2047027B/en not_active Expired
- 1980-04-03 AU AU57192/80A patent/AU534956B2/en not_active Ceased
- 1980-04-09 DE DE19803013550 patent/DE3013550A1/en active Granted
- 1980-04-11 FR FR8008138A patent/FR2454217A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| DE3013550A1 (en) | 1980-10-30 |
| GB2047027A (en) | 1980-11-19 |
| AU534956B2 (en) | 1984-02-23 |
| AU5719280A (en) | 1980-10-16 |
| FR2454217A1 (en) | 1980-11-07 |
| FR2454217B1 (en) | 1984-09-07 |
| US4262236A (en) | 1981-04-14 |
| DE3013550C2 (en) | 1989-05-18 |
| GB2047027B (en) | 1983-03-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1136697A (en) | Commutatorless direct current motor drive system | |
| CA1136698A (en) | Commutatorless direct current motor drive system | |
| US5254914A (en) | Position detection for a brushless DC motor without Hall effect devices using a mutual inductance detection method | |
| US4746844A (en) | Control and operation of brushless continuous torque toroid motor | |
| US4230976A (en) | Brushless, permanent magnet d-c motor with improved commutation control | |
| US5231338A (en) | Controlling a multiphase brushless motor without position sensors for the rotor, using a system of digital filtering | |
| JPS62173999A (en) | Commutating circuit of brushless dc motor | |
| US4827196A (en) | Motor control arrangement | |
| US3980933A (en) | Control circuit for variable reluctance motor | |
| US4409524A (en) | Arrangement for controlling the driving and braking current of a brushless D.C. motor | |
| US4282472A (en) | Digital generation and control of variable phase-on motor energization | |
| Wilson et al. | DC machine with solid-state commutation | |
| US3453512A (en) | Brushless dc motor | |
| JPS62502826A (en) | Brushless motor control circuit | |
| US3308362A (en) | Synchronous motor control circuit | |
| US3185910A (en) | Magnetic switch-scr for motor speed control system | |
| Panda et al. | Switched reluctance motor drive without direct rotor position sensing | |
| US3541408A (en) | Speed control circuit for brushless dc motor | |
| Bahlmann | A full-wave motor drive IC based on the back-EMF sensing principle | |
| Binns et al. | Implicit rotor position sensing using search coils for a self-commutating permanent magnet drive system | |
| US3395328A (en) | Direct current commutation system for brushless electrical motors | |
| US3671826A (en) | Stepping motor driver | |
| US3449654A (en) | Direct current commutation system for brushless electrical motors | |
| Kavanagh et al. | Innovative current sensing for brushless dc drives | |
| US3381192A (en) | Motor control circuitry responsive to a rotor position sensing arrangement |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |