CA1132276A - Telephone device - Google Patents
Telephone deviceInfo
- Publication number
- CA1132276A CA1132276A CA300,862A CA300862A CA1132276A CA 1132276 A CA1132276 A CA 1132276A CA 300862 A CA300862 A CA 300862A CA 1132276 A CA1132276 A CA 1132276A
- Authority
- CA
- Canada
- Prior art keywords
- pulse
- prohibited
- telephone
- telephone line
- train
- 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
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/66—Substation equipment, e.g. for use by subscribers with means for preventing unauthorised or fraudulent calling
- H04M1/677—Preventing the dialling or sending of predetermined telephone numbers or selected types of telephone numbers, e.g. long distance numbers
Abstract
ABSTRACT
A device for connecting to a telephone line to render a telephone incapable of originating prohibited calls has a computer with a memory and capable of being programmed with one or more digits or sets or digits which are intended to be prohibited and adapted to compare the dialled pulses with thone of the prohibited digit or digits and to originate an allow function or a prohibit function accordingly, and circuit terminating means for connection across the telephone line,connected to the computer and adapted upon receipt of the allow function or the prohibit function to leave the line unterminated or to terminate the line respectively
A device for connecting to a telephone line to render a telephone incapable of originating prohibited calls has a computer with a memory and capable of being programmed with one or more digits or sets or digits which are intended to be prohibited and adapted to compare the dialled pulses with thone of the prohibited digit or digits and to originate an allow function or a prohibit function accordingly, and circuit terminating means for connection across the telephone line,connected to the computer and adapted upon receipt of the allow function or the prohibit function to leave the line unterminated or to terminate the line respectively
Description
1~3Z'~76 The present invention relate~ to a deviee for connection to a telephone li~e to render a ~elephone ~hereon incapable of originating certain prohibited calls.
The obJect of the invention i9 to provide an improved device, of this nature, which may be connected in parallel across the ~wo wires of the telephone line, without xegard to polarity~ and which terminates the telephone line only for a short predete~mined period of time and only immediately upon occurrence o~ a dialling pu]Lse, whereafter the telephone line is again left unterminated~ whereby there is no interference with company lines and apparatus.
Acoording to the present invention a telephone device comprises:-(i~ a computer including a memory and capable of beingprogrammed with one or more digits or sets of digi$s which are intended to be prohibit0d, said computer being adapted to compare the dialled pulses with those of the prohibi~ed digit or digits, and to originate an "allow~ function or a "prohibit" function accordingly;
(ii) circuit terminating means, for connection across the telephone line, connected to the computer and adapted, upon receipt of said ~allow" function or said "prohibit"
function, to leave the line unterminated, or to terminate the lin~, respectively~
In a preferred arrangement, the computer includes means for conditioning the dialled pulses received ~rom the telephone line, means ~or detecting the train of dialled pulses, means for counting the dialled pulse train, and reject logic
The obJect of the invention i9 to provide an improved device, of this nature, which may be connected in parallel across the ~wo wires of the telephone line, without xegard to polarity~ and which terminates the telephone line only for a short predete~mined period of time and only immediately upon occurrence o~ a dialling pu]Lse, whereafter the telephone line is again left unterminated~ whereby there is no interference with company lines and apparatus.
Acoording to the present invention a telephone device comprises:-(i~ a computer including a memory and capable of beingprogrammed with one or more digits or sets of digi$s which are intended to be prohibit0d, said computer being adapted to compare the dialled pulses with those of the prohibi~ed digit or digits, and to originate an "allow~ function or a "prohibit" function accordingly;
(ii) circuit terminating means, for connection across the telephone line, connected to the computer and adapted, upon receipt of said ~allow" function or said "prohibit"
function, to leave the line unterminated, or to terminate the lin~, respectively~
In a preferred arrangement, the computer includes means for conditioning the dialled pulses received ~rom the telephone line, means ~or detecting the train of dialled pulses, means for counting the dialled pulse train, and reject logic
- 2 -:. ;.. :: . :
. ,-.
. ~ . . :.
. .
~ ::' -~ .
~3~'76 responsive to the counting means for producing an output signal ~or controlling the circuit terminating means.
In order that the nature o~ the invention m~y be readily ascertained7 an embo~iment o~ device in accordance therewith is hereina~ter particularly described with rererence to the figures o~ the accompanying drawings, wherein:
Fig.l is a block circuit diagram o~ the device;
Fig.2 is a circuit diagram of a power supply unit;
Fig.3 is n circuit diagram o~ a dial pulse conditioner;
Fig.4 is a circuit diagram of an "on~hook" detector;
Fig.5 is a circuit diagram o~ a coincidence gate;
Fig.6 is a circuit diagram of a memory latch assembly and logic;
Fig.7 is a diagram of a terminating circuit.
Referring to Fig.l~ there is shown a block circuit diagram of the telephone device intended ~or connecting across the two wires of a telephone line. Terminals "T" ~or connec~ion to the telephone line in either polarity, are connected to the device through diodes "R". All units are powered by a power supply A (fig.2) having connections ~Vcc and -Vcc for a battery~ A gas protector llpn is connected in parallel across the input. One Terminal "T" is connected to the input of a dial pulse conditioner B~ the output o~ which passes to a dial pulse counter F having outputs connected to a coincidence gate J. Another output of the dial pUlS& conditioner B passes to a dial pulse train detector C, from ~hich an output is connected through a dial pulse train counter G to other inputs of the coincidence gate J.
.
"
. . .
;22~6 Outputs ~rom the dial pulse conditioner B and the dial pulse train detector C also pass to an on~hoolc de~ec tor D
~rom which a first output passes to the dial pulse train counter G for "0" re-set, and to a memory latches and logic unit K for resetting.
A further connection is ma~e between the output of the dial pulse train detector C and ~m end-of-train detector E~
and from there to an end~of~lool~ detector H ha~ing its output connected to the dial pulse counter F for IIOtl xeset purposes.
Another connection is made between the output of the end-o~-train detector E and the coincidence gate J, The output of the dial pulse conditioner B is also taken to the coincidence gate J and to the memory latches and logic K.
Outputs from the coincidence gate J are taken to the memory latches and logic K, and an output of the latter passes to unit L which is an 88 millisecond one-shot re-triggerable positive-edge trigger. Output from unit L passes to a terminating circuit M~ and also to the input o~ the "on-hook"
detector D. The terminating circuit M has its inputs connected respecti~ely to the $elephone wire terminals "T".
The dial pulse train detector C is a 20~ millisecond one-shot re-~riggerable positive-edge trigger.
The end-of-train detector E is l-millisecond one-shot re-triggerable positive-edge trigger.
The dial p~lse counter F~ and the dial pulse train counter G are both counters of the kind known commercially under the designation "4017".
The end-of-look detector H is a l-millisecond one-shot re-triggerable negatiYe-edge trigger.
~he one-shot trigger units may be the kind known -- 4 ~
, ~. . .
7~i commercially under the designatio~ "4528 duals"~
The circuit terminating means are installed across the telephone line such that termination o~ the line, resulting from the dialling o~ a prohibited signal, makes the calling o~ that prohibited num~er impossible.
The derice, when conne~ted across any telephone line, renders all telephones on that line incapable of ~aking prohibited callsJ e.g. long distance calls or information calls. ~here there are a number of telephones OII a line and it is desired to permit otherwise prohibited calls to be made only from a certain selected telephone or telephone there may be provided switching means located at each such privileged telephoneg or otherwise convenienkly~ ~or temporarîly disconnecting the device or rendering it non-operative.
The device has only two terminals which can be connected across the telephone li~e in either polarity and anywhere along the telephone line, a~d the device per~orms its ~unctions without the need of external power other than a small drain from the telephone line itsel~.
By way o~ stration of operation o~ the device, telephvne dial pulses open the telephone line for 66 milliseconds for each pulse, interspersed with terminat on of the line for 44 milliseconds between pulses. In the case of a "zeron being dialled~ ~it being assumed that a zero at the com~encement denotes a prohibitable call), the device of this învention senses the tenth pulse starting~ and immediately terminates the line ~or 88 milliseconds, thus eliminating the tsnth pulse, and the prohibited nwmber "zero" as a ~irst digit.
, .
~3L32~
Any subsequent dlal pulses are likewise eliminated until the unit senses an "on hook" condition (an open state lo~ger than 88 milliseconds3, upon which the device re~sets its memories.
In the case of the number ~41~1 (again assumed to denote a prohibitable call) being dialled ~irs~, all subsequent dialled pulses are ~horted out or eliminated until the ~on hook" condition ls sensed. This is correct in the conte~t o~ there being no seven digit telephone numbers commencing with "41~.
In the cass o~ direct-dial long distance numbers, e.g~
"1" followed by seven or ten digits, the second, third and fourth digi~s are registered. If these digits are ~8"~
"O" and "O", (denoting certain long-distance call~ not chargeable to $he caller) all eight or eleven digits are allowed. If the second, third and fourth digits are not "8n, "O" and "O", every dialled pulse a~ter the seventh digit is elimina$ed or shorted out, until the "on hookl9 condition is sensed.
. ,-.
. ~ . . :.
. .
~ ::' -~ .
~3~'76 responsive to the counting means for producing an output signal ~or controlling the circuit terminating means.
In order that the nature o~ the invention m~y be readily ascertained7 an embo~iment o~ device in accordance therewith is hereina~ter particularly described with rererence to the figures o~ the accompanying drawings, wherein:
Fig.l is a block circuit diagram o~ the device;
Fig.2 is a circuit diagram of a power supply unit;
Fig.3 is n circuit diagram o~ a dial pulse conditioner;
Fig.4 is a circuit diagram of an "on~hook" detector;
Fig.5 is a circuit diagram o~ a coincidence gate;
Fig.6 is a circuit diagram of a memory latch assembly and logic;
Fig.7 is a diagram of a terminating circuit.
Referring to Fig.l~ there is shown a block circuit diagram of the telephone device intended ~or connecting across the two wires of a telephone line. Terminals "T" ~or connec~ion to the telephone line in either polarity, are connected to the device through diodes "R". All units are powered by a power supply A (fig.2) having connections ~Vcc and -Vcc for a battery~ A gas protector llpn is connected in parallel across the input. One Terminal "T" is connected to the input of a dial pulse conditioner B~ the output o~ which passes to a dial pulse counter F having outputs connected to a coincidence gate J. Another output of the dial pUlS& conditioner B passes to a dial pulse train detector C, from ~hich an output is connected through a dial pulse train counter G to other inputs of the coincidence gate J.
.
"
. . .
;22~6 Outputs ~rom the dial pulse conditioner B and the dial pulse train detector C also pass to an on~hoolc de~ec tor D
~rom which a first output passes to the dial pulse train counter G for "0" re-set, and to a memory latches and logic unit K for resetting.
A further connection is ma~e between the output of the dial pulse train detector C and ~m end-of-train detector E~
and from there to an end~of~lool~ detector H ha~ing its output connected to the dial pulse counter F for IIOtl xeset purposes.
Another connection is made between the output of the end-o~-train detector E and the coincidence gate J, The output of the dial pulse conditioner B is also taken to the coincidence gate J and to the memory latches and logic K.
Outputs from the coincidence gate J are taken to the memory latches and logic K, and an output of the latter passes to unit L which is an 88 millisecond one-shot re-triggerable positive-edge trigger. Output from unit L passes to a terminating circuit M~ and also to the input o~ the "on-hook"
detector D. The terminating circuit M has its inputs connected respecti~ely to the $elephone wire terminals "T".
The dial pulse train detector C is a 20~ millisecond one-shot re-~riggerable positive-edge trigger.
The end-of-train detector E is l-millisecond one-shot re-triggerable positive-edge trigger.
The dial p~lse counter F~ and the dial pulse train counter G are both counters of the kind known commercially under the designation "4017".
The end-of-look detector H is a l-millisecond one-shot re-triggerable negatiYe-edge trigger.
~he one-shot trigger units may be the kind known -- 4 ~
, ~. . .
7~i commercially under the designatio~ "4528 duals"~
The circuit terminating means are installed across the telephone line such that termination o~ the line, resulting from the dialling o~ a prohibited signal, makes the calling o~ that prohibited num~er impossible.
The derice, when conne~ted across any telephone line, renders all telephones on that line incapable of ~aking prohibited callsJ e.g. long distance calls or information calls. ~here there are a number of telephones OII a line and it is desired to permit otherwise prohibited calls to be made only from a certain selected telephone or telephone there may be provided switching means located at each such privileged telephoneg or otherwise convenienkly~ ~or temporarîly disconnecting the device or rendering it non-operative.
The device has only two terminals which can be connected across the telephone li~e in either polarity and anywhere along the telephone line, a~d the device per~orms its ~unctions without the need of external power other than a small drain from the telephone line itsel~.
By way o~ stration of operation o~ the device, telephvne dial pulses open the telephone line for 66 milliseconds for each pulse, interspersed with terminat on of the line for 44 milliseconds between pulses. In the case of a "zeron being dialled~ ~it being assumed that a zero at the com~encement denotes a prohibitable call), the device of this învention senses the tenth pulse starting~ and immediately terminates the line ~or 88 milliseconds, thus eliminating the tsnth pulse, and the prohibited nwmber "zero" as a ~irst digit.
, .
~3L32~
Any subsequent dlal pulses are likewise eliminated until the unit senses an "on hook" condition (an open state lo~ger than 88 milliseconds3, upon which the device re~sets its memories.
In the case of the number ~41~1 (again assumed to denote a prohibitable call) being dialled ~irs~, all subsequent dialled pulses are ~horted out or eliminated until the ~on hook" condition ls sensed. This is correct in the conte~t o~ there being no seven digit telephone numbers commencing with "41~.
In the cass o~ direct-dial long distance numbers, e.g~
"1" followed by seven or ten digits, the second, third and fourth digi~s are registered. If these digits are ~8"~
"O" and "O", (denoting certain long-distance call~ not chargeable to $he caller) all eight or eleven digits are allowed. If the second, third and fourth digits are not "8n, "O" and "O", every dialled pulse a~ter the seventh digit is elimina$ed or shorted out, until the "on hookl9 condition is sensed.
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A device for connection to a telephone line to render a telephone incapable of originating prohibited calls comprising:
(a) dial pulse detector means for detecting the presence of dialling pulses;
(b) first pulse counter means coupled to said telephone line for counting the number of dialling pulses received;
(c) second pulse counter means for counting the number of pulse trains detected by said pulse detector means;
(d) end of train detector means for detecting the end of a pulse train;
(e) gating means for receiving the outputs of the first and second pulse counters when the end of a pulse train is detected by the end of train detector means;
(f) memory and logic means for receiving the output from the gating means to determine the identity of the pulse information and to provide a signal indicative of the presence of a prohibited number, (g) termination means responsive to said signal to terminate the passage of dialling pulses wherever a prohibited number is detected, and (h) a monostable multivibrator connected between the memory and logic means and the termination means to provide a signal for said termination means for a predetermined time period.
(a) dial pulse detector means for detecting the presence of dialling pulses;
(b) first pulse counter means coupled to said telephone line for counting the number of dialling pulses received;
(c) second pulse counter means for counting the number of pulse trains detected by said pulse detector means;
(d) end of train detector means for detecting the end of a pulse train;
(e) gating means for receiving the outputs of the first and second pulse counters when the end of a pulse train is detected by the end of train detector means;
(f) memory and logic means for receiving the output from the gating means to determine the identity of the pulse information and to provide a signal indicative of the presence of a prohibited number, (g) termination means responsive to said signal to terminate the passage of dialling pulses wherever a prohibited number is detected, and (h) a monostable multivibrator connected between the memory and logic means and the termination means to provide a signal for said termination means for a predetermined time period.
2. A device according to claim 1 wherein said gating means comprise a plurality of NAND gates.
3. A device according to claim 1 wherein said memory and logic means comprises a plurality of bistable elements connected to inputs of NAND gates.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA300,862A CA1132276A (en) | 1978-04-11 | 1978-04-11 | Telephone device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA300,862A CA1132276A (en) | 1978-04-11 | 1978-04-11 | Telephone device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1132276A true CA1132276A (en) | 1982-09-21 |
Family
ID=4111203
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA300,862A Expired CA1132276A (en) | 1978-04-11 | 1978-04-11 | Telephone device |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1132276A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1985000716A1 (en) * | 1983-07-21 | 1985-02-14 | Malca Pty. Ltd. | Telephone trunk barring device |
| US5200995A (en) * | 1990-12-24 | 1993-04-06 | Gaukel John J | Universal outgoing call restriction circuit |
| US5898756A (en) * | 1995-10-13 | 1999-04-27 | Zoom Telephonics, Inc. | Parallel-connected dialing signal transmission-inhibiting device for data transfer over a telephone link |
-
1978
- 1978-04-11 CA CA300,862A patent/CA1132276A/en not_active Expired
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1985000716A1 (en) * | 1983-07-21 | 1985-02-14 | Malca Pty. Ltd. | Telephone trunk barring device |
| US5200995A (en) * | 1990-12-24 | 1993-04-06 | Gaukel John J | Universal outgoing call restriction circuit |
| US5898756A (en) * | 1995-10-13 | 1999-04-27 | Zoom Telephonics, Inc. | Parallel-connected dialing signal transmission-inhibiting device for data transfer over a telephone link |
| US6711238B1 (en) | 1995-10-13 | 2004-03-23 | Zoom Telephonics, Inc. | Parallel-connected dialing signal transmission inhibiting device for data transfer over a telephone link |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |