WO1997012258A1 - Transponder containing measuring circuit - Google Patents

Transponder containing measuring circuit Download PDF

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Publication number
WO1997012258A1
WO1997012258A1 PCT/NL1996/000375 NL9600375W WO9712258A1 WO 1997012258 A1 WO1997012258 A1 WO 1997012258A1 NL 9600375 W NL9600375 W NL 9600375W WO 9712258 A1 WO9712258 A1 WO 9712258A1
Authority
WO
WIPO (PCT)
Prior art keywords
circuit
transponder
sensor
time
measuring circuit
Prior art date
Application number
PCT/NL1996/000375
Other languages
French (fr)
Dutch (nl)
Inventor
Willem Johannes Eradus
Original Assignee
Instituut Voor Milieu- En Agritechniek (Imag-Dlo)
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Instituut Voor Milieu- En Agritechniek (Imag-Dlo) filed Critical Instituut Voor Milieu- En Agritechniek (Imag-Dlo)
Priority to AU71470/96A priority Critical patent/AU7147096A/en
Publication of WO1997012258A1 publication Critical patent/WO1997012258A1/en

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
    • G01S13/75—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems using transponders powered from received waves, e.g. using passive transponders, or using passive reflectors
    • G01S13/751—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems using transponders powered from received waves, e.g. using passive transponders, or using passive reflectors wherein the responder or reflector radiates a coded signal
    • G01S13/758—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems using transponders powered from received waves, e.g. using passive transponders, or using passive reflectors wherein the responder or reflector radiates a coded signal using a signal generator powered by the interrogation signal
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K1/00—Details of thermometers not specially adapted for particular types of thermometer
    • G01K1/02—Means for indicating or recording specially adapted for thermometers
    • G01K1/022—Means for indicating or recording specially adapted for thermometers for recording

Definitions

  • the invention relates to a transponder provided with: a receiving circuit for receiving interrogation signals and electro- magnetic field energy, energy storage means for storing the received electromagnetic field energy and for delivering power to the transponder, interrogation signal processing means for detecting the interrogation signal, a measuring circuit coupled to one or more sensors for measuring the value of one or more ambient parameters, a transmitting circuit which, after reception of an interrogation signal, transmits the parameter value(s) measured by the measuring circuit.
  • a transponder is described, for example, in US Patent Publica- tion US-5,073,781.
  • This transponder functions in such a way that, whenever an interrogation signal is received, electromagnetic energy is drawn from the interrogation field and is stored in the energy storage means, which are constructed as a capacitor. As soon as the capacitor is completely charged, the interrogation signal processing means are activated and after recognition of the interrogation signal they activate the measuring circuit with which an external ambient parameter value, for example the current temperature, is measured by means of the sensor coupled to it. The trans ⁇ mitting circuit, which first of all transmits an identification signal and then the measured parameter value is then also activated. Provided said transponder is situated in the interrogation field and therefore receives interrogation signals and high-frequency electromagnetic field energy, the measuring circuit can also be activated to measure and transmit the current ambient parameter value.
  • the energy from the capacitor will be used up after a relatively short time and the transponder therefore becomes com ⁇ pletely passive. With this transponder, it is therefore possible to carry out measurements only at times at which the transponder is situated in the interrogation field and an interrogation signal is therefore received.
  • a device known per se with which measured values can be generated which are independent of the occurrence of an interrogation signal is described in US Patent Publication US-4,865,044.
  • Said device contains a clock generator, a time-determining circuit, a code generator, a tempera ⁇ ture measuring circuit and a transmitter.
  • Said known device is furthermore provided with a battery with which the various circuits in the device are supplied.
  • said known device is furthermore provided with a time-determining circuit with which the code generator, the temperature measuring device and the transmitter are activated only briefly at predetermined times in order to measure and transmit the temperature at the respective times. In the intervening periods, only the clock-pulse generator is active for switching a clock mechanism or counter mechanism until the subsequent predetermined time is reached.
  • a further disadvantage of said known device is formed by the fact that the range of the transmitter is relatively limited.
  • the range of the transmitter is relatively limited.
  • this can encounter practical drawbacks.
  • the object of the invention is therefore to provide a transponder of the type mentioned in the introduction, which transponder has an infinite service life (disregarding wear and ageing phenomena) and with which measured values can also be obtained at times which are situated between the times at which the transponder enters an interrogation field.
  • a transponder of the type mentioned in the introduction in that it is furthermore provided with a time-determining circuit which activates the measuring circuit at predetermined times to carry out one or more measurements of the said ambient parameter(s) , - the measurement circuit is provided with a memory in which a number of measured parameter values can be stored, and the energy storage means have sufficient capacity to supply power within a predetermined period to the time-determining circuit in order to keep it in operation during said period and also to supply power to the measuring circuit insofar as it is activated within the said period by the time-determining circuit.
  • FIG. 1 shows a block diagram of the transponder known from the prior art.
  • FIG. 2 shows a block diagram of the transponder according to the invention.
  • FIG. 1 shows diagrammatically in the form of a block diagram a transponder such as is known from the above-mentioned prior art.
  • Said transponder comprises in its generality a receiving circuit 10, energy storage means 12, an interrogation signal processing circuit 14, a measur ⁇ ing circuit 16 which is coupled to a sensor 18 for measuring an ambient parameter, and a transmitting circuit 20.
  • the receiving circuit 10 essentially comprises a tuned circuit com- posed of the diagrammatically indicated combination of a coil 24 and a capacitor 22, which circuit is tuned to the frequency at which the interro ⁇ gation signal is generated. If the receiving circuit 10 receives an inter ⁇ rogation signal in the form of modulated high-frequency electromagnetic field energy, this signal will, on the one hand, be passed to the energy storage means 12 and will also be passed to an interrogation signal pro ⁇ cessing circuit 14. The high-frequency electromagnetic field energy in the interrogation signal is used in the storage means 12 to charge an energy reservoir which is designed as a capacitor. The energy collected in said energy reservoir is then used, at least temporarily, to supply the signal processing circuit 14, the measuring circuit 16 with associated sensor 18 and the transmitting circuit 20.
  • the interrogation signal processing circuit 14 will become active and will be able to detect the interrogation signal in the received high-frequency electromagnetic field energy. As soon as the interrogation signal is detected, the signal processing circuit 14 delivers an activation signal to the measuring circuit 16 which, in response to said signal, detects a measured value of the sensor 18. The detected measured value is trans ⁇ mitted from the measuring circuit 16 to the transmitting circuit 20, which has also been activated in the meantime by the signal processing circuit 14. Finally the transmitting circuit 20 ensures that the detected measured value is transmitted in a high-frequency signal train to the external interrogating station.
  • the oscillatory circuit which is also present in the receiving circuit 10 to transmit said signal, as is assumed in Figure 1, but, on the other hand, use can also be made of a separate oscillatory circuit, which is not shown in the figure.
  • a measurement is carried out only after reception of an interrogation signal transmitted by an external interrogation station and the respective measured value is transmitted to the interrogation sta ⁇ tion immediately thereafter. If the transponder is situated outside the sphere of influence of the interrogation station, the energy storage means (the capacitor 12) are discharged and the transponder is inactive.
  • transponder one embodi- ment of which is illustrated diagrammatically in the form of a block dia ⁇ gram in Figure 2.
  • Said transponder comprises the receiving circuit 30 which contains within it the oscillatory circuit having coil 26 and capacitor 28, the energy storage means 32, the interrogation signal pro- cessing circuit 34, the measuring circuit 36 with associated sensor 38, and the transmitting circuit 40.
  • the transponder from Figure 2 comprises, in addition, a memory 42 and a time-determining circuit 44.
  • the energy storage means 32 are designed in such a way that its capacity is sufficient also to be able to carry out measurements between two interrogation signals and to store the measured values found in the memory, as will be explained in greater detail below.
  • the interrogation signal processing circuit 34 is put into operation and the interrogation signal is detected.
  • the other circuits such as the transmitting circuit 40 and the memory 42, are activated.
  • the memory 42 contains one or more measured values and these are now supplied sequentially to the transmitting circuit 40 and transmitted to the interrogation station after modulation in a suit ⁇ able high-frequency signal.
  • the storage means 32 are provided in this transponder with a chemi ⁇ cally inactive capacitor or a chemically active battery or storage battery.
  • the storage means have sufficient capacity to be able to store a relatively large quantity of energy with which, as will be further described below, the time-determining circuit 44 and, insofar as necessary, also the measuring circuit 36 and possibly the memory 42 can always be supplied until the receipt of a subsequent interrogation signal.
  • time-determining circuit 44 contains, inter alia, a clock circuit and a clock-pulse generator, with which pulses are delivered to the clock circuit.
  • a signal with which the measuring circuit 36 with associated sensor 38 and the memory 42 are temporarily activated is generated by the time-determining circuit after termination of a predetermined period.
  • the measuring circuit 36 then generates, on the basis of the signal received by the sensor 38, a measured value and said measured value is stored in the memory 42.
  • both the measuring circuit 36 with associated sensor 38 and the memory 42 are again inactivated and the time-determining circuit 44 begins to measure a subsequent predeter ⁇ mined period. During said period, energy is therefore used up only by the time-determining circuit 44.
  • a mea ⁇ surement is again carried out and the measured value obtained is stored in the memory, etc. This takes place just until the transponder enters the interrogation field of an interrogation station. As soon as that happens, the storage means are recharged and the various circuits in the transponder are activated.
  • the memory 42 is read out and the measurement data stored in it and collected in the period after the preceding interrogation signal are transmitted to the interrogation station.
  • the time-determining circuit can be designed in such a way that a signal is generated to carry out a measure ⁇ ment and to store the measured value obtained in the memory at predeter- mined programmed-m times or in a predetermined sequence of different periods.
  • the measuring circuit 36 or at least a part of it in operation during fairly long periods or even continuously. That is the case, for example, for integrating measurements, such as the measurement of movements.
  • the measuring circuit, or at least that part of it which has to remain switched on, can generally be designed in such a way that its power consumption is very low.
  • the memory 42 a type in which the information remains present even if the supply voltage fails so that the memory has to be activated only during the storage of new measured values or during the reading-out of measured values.
  • the energy which is stored in the storage means 32 is sufficient to be able to bridge fairly long periods between the interrogation signals without the voltage to the time-determm- mg means falling off. Because the charging of a discharged storage capacitor or a discharged battery or storage battery may take a relatively long time and because it is not always possible to bring the transponder within the interrogation field during this required time, it is preferable to dimension the energy storage means so that their capacity is sufficient to allow the transponder to function correctly even n "worst case" situ ⁇ ations. This achieves the result that, even in the case where the energy storage means are not completely recharged every time, a reliable and reg- ular series of measured values is nevertheless obtained.
  • an inter ⁇ rogation station can be installed, for example, in the vicinity of the milking machine so that the charge in the energy storage means of the transponder is topped up during each milking session, which requires a certain time.
  • An interrogation station can also be installed in the vicin ⁇ ity of the feeding points so that the charge in the energy storage means of the transponder is topped up each time an animal visits the feeding point.
  • the transponder is used for pigs, the above-mentioned situations do not occur.
  • the freedom of movement of pigs is often more limited and it is possible, for example, to make use of an interroga ⁇ tion station which is linked to a ring-conductor-type aerial in the pigsty so that the transponder will always be in the interrogation field for a relatively long time and the periods in which the transponder is not in the interrogation field are relatively short.
  • the capacity of the storage means in the transponder can be selected as rela ⁇ tively low.
  • transponders are described in which the transponder is provided with a single sensor.
  • a plurality of sen ⁇ sors for measuring various parameters, for example a first sensor for measuring temperature and a second sensor for measuring movements.
  • the time-determining circuit also to be provided with a selection circuit which indicates at each set or programmed clock time or after each specified period which sensor(s) has(have) to be activated in order to measure the respective current parameter value and store it in the memory.

Abstract

Transponder provided with: a receiving circuit for receiving interrogation signals and electromagnetic field energy, energy storage means for storing the received electromagnetic field energy and for delivering power to the transponder, interrogation signal processing means for detecting the interrrogation signal, a measuring circuit coupled to one or more sensors for measuring the value of one or more external ambient parameters, and a transmitting circuit which, after reception of an interrogation signal, transmits the parameter value(s) measured by the measuring circuit. The transponder is furthermore provided with a time-determining circuit which activates the measuring circuit at predetermined times to carry out one or more measurements of the said ambient parameter(s). The measuring circuit is provided with a memory in which a number of measured parameter values can be stored. The energy storage means have sufficient capacity to supply power within a predetermined period to the time-determining circuit in order to keep it in operation during said period and also to supply power to the measuring circuit if it is activated within said period by the time-determining circuit.

Description

Transponder containing measuring circuit
The invention relates to a transponder provided with: a receiving circuit for receiving interrogation signals and electro- magnetic field energy, energy storage means for storing the received electromagnetic field energy and for delivering power to the transponder, interrogation signal processing means for detecting the interrogation signal, a measuring circuit coupled to one or more sensors for measuring the value of one or more ambient parameters, a transmitting circuit which, after reception of an interrogation signal, transmits the parameter value(s) measured by the measuring circuit. Such a transponder is described, for example, in US Patent Publica- tion US-5,073,781. This transponder functions in such a way that, whenever an interrogation signal is received, electromagnetic energy is drawn from the interrogation field and is stored in the energy storage means, which are constructed as a capacitor. As soon as the capacitor is completely charged, the interrogation signal processing means are activated and after recognition of the interrogation signal they activate the measuring circuit with which an external ambient parameter value, for example the current temperature, is measured by means of the sensor coupled to it. The trans¬ mitting circuit, which first of all transmits an identification signal and then the measured parameter value is then also activated. Provided said transponder is situated in the interrogation field and therefore receives interrogation signals and high-frequency electromagnetic field energy, the measuring circuit can also be activated to measure and transmit the current ambient parameter value. If the transponder leaves the interrogation field, the energy from the capacitor will be used up after a relatively short time and the transponder therefore becomes com¬ pletely passive. With this transponder, it is therefore possible to carry out measurements only at times at which the transponder is situated in the interrogation field and an interrogation signal is therefore received.
Circuits which operate in a similar manner and also become active only if they come within the sphere of influence of an interrogating sta¬ tion are described in Patent Publications US-4,075,632, US-5,053,774, US-5,252,962, EP-0,395, 188, EP-0,554,955, DE-3,219,558, DE-3,932,428, DE- 3,922,556 and GB-2,258,588. From the various publications mentioned above it is evident that sensors of various types can be used, for example for measuring tempera¬ ture, pressure, light, force, torsion etc. Biosensors can also be used to measure pH, glucose content and the like. Furthermore, it is also possible to use combinations of sensors to determine consecutively or simultaneously the values of a number of parameters.
In many situations it is desirable not only to obtain measured values at those instants at which the transponder is situated within an interroga¬ tion field, but also to obtain measured values which relate to other times. A device known per se with which measured values can be generated which are independent of the occurrence of an interrogation signal is described in US Patent Publication US-4,865,044. Said device contains a clock generator, a time-determining circuit, a code generator, a tempera¬ ture measuring circuit and a transmitter. Said known device is furthermore provided with a battery with which the various circuits in the device are supplied. In order to make the service life of the battery as long as possible, said known device is furthermore provided with a time-determining circuit with which the code generator, the temperature measuring device and the transmitter are activated only briefly at predetermined times in order to measure and transmit the temperature at the respective times. In the intervening periods, only the clock-pulse generator is active for switching a clock mechanism or counter mechanism until the subsequent predetermined time is reached.
One of the disadvantages of said known transponder is the fact that a battery has to be present and, despite all attempts to allow the device as a whole to function at as low a power as possible, said battery neverthe¬ less has a limited service life. In US-4,865,044, a service life is men¬ tioned which varies from six months to 2.1 years, depending on the embodi¬ ment. In many cases, however, a much longer service life will be desir- able. If, for example, a transponder is used to monitor the body tempera¬ ture of animals, account will have to be taken of the expected life of the respective animal, which may be much longer. If the service life of the transponder is shorter than the life of the animal, it is consequently necessary either to replace the transponder as a whole or to replace the battery of the transponder.
A further disadvantage of said known device is formed by the fact that the range of the transmitter is relatively limited. In one embodi¬ ment, mention is made of a range of 50 feet (approximately 15 metres), which implies that, depending on the field of application, a large number of receivers sited in a relatively spread-out manner is necessary to be able to receive all the signals transmitted by the respective device. In practice, this can encounter practical drawbacks. The object of the invention is therefore to provide a transponder of the type mentioned in the introduction, which transponder has an infinite service life (disregarding wear and ageing phenomena) and with which measured values can also be obtained at times which are situated between the times at which the transponder enters an interrogation field. This object is achieved by a transponder of the type mentioned in the introduction in that it is furthermore provided with a time-determining circuit which activates the measuring circuit at predetermined times to carry out one or more measurements of the said ambient parameter(s) , - the measurement circuit is provided with a memory in which a number of measured parameter values can be stored, and the energy storage means have sufficient capacity to supply power within a predetermined period to the time-determining circuit in order to keep it in operation during said period and also to supply power to the measuring circuit insofar as it is activated within the said period by the time-determining circuit.
The invention will be explained in greater detail below by reference to the accompanying figures.
Figure 1 shows a block diagram of the transponder known from the prior art.
Figure 2 shows a block diagram of the transponder according to the invention.
Figure 1 shows diagrammatically in the form of a block diagram a transponder such as is known from the above-mentioned prior art. Said transponder comprises in its generality a receiving circuit 10, energy storage means 12, an interrogation signal processing circuit 14, a measur¬ ing circuit 16 which is coupled to a sensor 18 for measuring an ambient parameter, and a transmitting circuit 20.
The receiving circuit 10 essentially comprises a tuned circuit com- posed of the diagrammatically indicated combination of a coil 24 and a capacitor 22, which circuit is tuned to the frequency at which the interro¬ gation signal is generated. If the receiving circuit 10 receives an inter¬ rogation signal in the form of modulated high-frequency electromagnetic field energy, this signal will, on the one hand, be passed to the energy storage means 12 and will also be passed to an interrogation signal pro¬ cessing circuit 14. The high-frequency electromagnetic field energy in the interrogation signal is used in the storage means 12 to charge an energy reservoir which is designed as a capacitor. The energy collected in said energy reservoir is then used, at least temporarily, to supply the signal processing circuit 14, the measuring circuit 16 with associated sensor 18 and the transmitting circuit 20.
As soon as sufficient energy is present in the capacitor 12, the interrogation signal processing circuit 14 will become active and will be able to detect the interrogation signal in the received high-frequency electromagnetic field energy. As soon as the interrogation signal is detected, the signal processing circuit 14 delivers an activation signal to the measuring circuit 16 which, in response to said signal, detects a measured value of the sensor 18. The detected measured value is trans¬ mitted from the measuring circuit 16 to the transmitting circuit 20, which has also been activated in the meantime by the signal processing circuit 14. Finally the transmitting circuit 20 ensures that the detected measured value is transmitted in a high-frequency signal train to the external interrogating station. Depending on the circuit, use can be made of the oscillatory circuit which is also present in the receiving circuit 10 to transmit said signal, as is assumed in Figure 1, but, on the other hand, use can also be made of a separate oscillatory circuit, which is not shown in the figure. With such circuits, a measurement is carried out only after reception of an interrogation signal transmitted by an external interrogation station and the respective measured value is transmitted to the interrogation sta¬ tion immediately thereafter. If the transponder is situated outside the sphere of influence of the interrogation station, the energy storage means (the capacitor 12) are discharged and the transponder is inactive.
For many applications, there is a need for a transponder with which it is possible to carry out measurements between two consecutive interroga¬ tion signals.
The invention now meets this need with the transponder, one embodi- ment of which is illustrated diagrammatically in the form of a block dia¬ gram in Figure 2. Said transponder comprises the receiving circuit 30 which contains within it the oscillatory circuit having coil 26 and capacitor 28, the energy storage means 32, the interrogation signal pro- cessing circuit 34, the measuring circuit 36 with associated sensor 38, and the transmitting circuit 40. Up to this point, there is similarity to the transponder illustrated in Figure 1. However, the transponder from Figure 2 comprises, in addition, a memory 42 and a time-determining circuit 44. Furthermore, the energy storage means 32 are designed in such a way that its capacity is sufficient also to be able to carry out measurements between two interrogation signals and to store the measured values found in the memory, as will be explained in greater detail below.
When an interrogation signal is received, energy is drawn from the high-frequency electromagnetic field in the same way as described above for the transponder of Figure 1 and said energy is used to charge the energy storage means 32. As soon as sufficient energy has been charged into the storage means, the interrogation signal processing circuit 34 is put into operation and the interrogation signal is detected. In response to the latter, the other circuits, such as the transmitting circuit 40 and the memory 42, are activated. The memory 42 contains one or more measured values and these are now supplied sequentially to the transmitting circuit 40 and transmitted to the interrogation station after modulation in a suit¬ able high-frequency signal. The storage means 32 are provided in this transponder with a chemi¬ cally inactive capacitor or a chemically active battery or storage battery. In each case, the storage means have sufficient capacity to be able to store a relatively large quantity of energy with which, as will be further described below, the time-determining circuit 44 and, insofar as necessary, also the measuring circuit 36 and possibly the memory 42 can always be supplied until the receipt of a subsequent interrogation signal.
After termination of the interrogation signal and after the trans¬ mission of the measured values stored in the memory 42, a large part of the transponder will be inactivated, with the exception of the time-determining circuit 44. Said time-determining circuit 44 contains, inter alia, a clock circuit and a clock-pulse generator, with which pulses are delivered to the clock circuit. In a simple embodiment, a signal with which the measuring circuit 36 with associated sensor 38 and the memory 42 are temporarily activated is generated by the time-determining circuit after termination of a predetermined period. The measuring circuit 36 then generates, on the basis of the signal received by the sensor 38, a measured value and said measured value is stored in the memory 42. Then both the measuring circuit 36 with associated sensor 38 and the memory 42 are again inactivated and the time-determining circuit 44 begins to measure a subsequent predeter¬ mined period. During said period, energy is therefore used up only by the time-determining circuit 44. At the end of the subsequent period, a mea¬ surement is again carried out and the measured value obtained is stored in the memory, etc. This takes place just until the transponder enters the interrogation field of an interrogation station. As soon as that happens, the storage means are recharged and the various circuits in the transponder are activated. After recognition of the interrogation signal in the recog¬ nition circuit 34, the memory 42 is read out and the measurement data stored in it and collected in the period after the preceding interrogation signal are transmitted to the interrogation station.
In a more advanced embodiment, the time-determining circuit can be designed in such a way that a signal is generated to carry out a measure¬ ment and to store the measured value obtained in the memory at predeter- mined programmed-m times or in a predetermined sequence of different periods.
Depending on the parameter to be measured it may be necessary to keep not only the time-determining circuit 44, but also the measuring circuit 36 or at least a part of it in operation during fairly long periods or even continuously. That is the case, for example, for integrating measurements, such as the measurement of movements. The measuring circuit, or at least that part of it which has to remain switched on, can generally be designed in such a way that its power consumption is very low.
It is furthermore preferable to use for the memory 42 a type in which the information remains present even if the supply voltage fails so that the memory has to be activated only during the storage of new measured values or during the reading-out of measured values.
In the above, it has been assumed that the energy which is stored in the storage means 32 is sufficient to be able to bridge fairly long periods between the interrogation signals without the voltage to the time-determm- mg means falling off. Because the charging of a discharged storage capacitor or a discharged battery or storage battery may take a relatively long time and because it is not always possible to bring the transponder within the interrogation field during this required time, it is preferable to dimension the energy storage means so that their capacity is sufficient to allow the transponder to function correctly even n "worst case" situ¬ ations. This achieves the result that, even in the case where the energy storage means are not completely recharged every time, a reliable and reg- ular series of measured values is nevertheless obtained.
If the transponder is used, for example, for dairy cattle, an inter¬ rogation station can be installed, for example, in the vicinity of the milking machine so that the charge in the energy storage means of the transponder is topped up during each milking session, which requires a certain time. An interrogation station can also be installed in the vicin¬ ity of the feeding points so that the charge in the energy storage means of the transponder is topped up each time an animal visits the feeding point.
If the transponder is used for pigs, the above-mentioned situations do not occur. On the other hand, the freedom of movement of pigs is often more limited and it is possible, for example, to make use of an interroga¬ tion station which is linked to a ring-conductor-type aerial in the pigsty so that the transponder will always be in the interrogation field for a relatively long time and the periods in which the transponder is not in the interrogation field are relatively short. Under those circumstances, the capacity of the storage means in the transponder can be selected as rela¬ tively low.
In the above, several embodiments of transponders are described in which the transponder is provided with a single sensor. However, within the scope of the invention, it is also possible to use a plurality of sen¬ sors for measuring various parameters, for example a first sensor for measuring temperature and a second sensor for measuring movements. Because not all the sensors need to be active at the same times, it is preferable in that case for the time-determining circuit also to be provided with a selection circuit which indicates at each set or programmed clock time or after each specified period which sensor(s) has(have) to be activated in order to measure the respective current parameter value and store it in the memory.

Claims

PC17NL96/003758Claims
1. Transponder provided with: a receiving circuit for receiving interrogation signals and electro¬ magnetic field energy, - energy storage means for storing the received electromagnetic field energy and for delivering power to the transponder, interrogation signal processing means for detecting the interrogation signal, a measuring circuit coupled to one or more sensors for measuring the value of one or more external ambient parameters, and a transmitting circuit which, after reception of an interrogation signal transmits the parameter value(s) measured by the measuring circuit, characterized in that the transponder is furthermore provided with a time-determin- ing circuit which activates the measuring circuit at predetermined times to carry out one or more measurements of the said ambient parameter(s) , in that the measuring circuit is provided with a memory in which a number of measured parameter values can be stored, and in that the energy storage means have sufficient capacity to supply power within a predetermined period to the time-determining circuit in order to keep it in operation during said period and also to supply power to the measuring circuit insofar as it is activated within the said period by the time-determining circuit.
2. Transponder according to Claim 1, characterized in that the energy storage means are provided with a chemically inactive energy storage element such as a capacitor.
3. Transponder according to Claim 1, characterized in that the energy storage means are provided with a chemically active energy storage element such as a battery or storage battery.
4. Transponder according to Claim 1, 2 or 3, characterized in that the time-determining circuit is provided with a clock which can be set or pro¬ grammed to activate the measuring circuit at the set or programmed clock times.
5. Transponder according to Claim 1, 2 or 3, characterized in that the time-determining circuit is provided with a period measuring circuit which can be set or programmed to activate the measuring circuit always after a certain period.
6. Transponder according to one of Claims 4 or 5, characterized in that the transponder is provided with two or more sensors and in that the time- determining circuit is also provided with a selection circuit which indi¬ cates at each set or programmed clock time or after each specified period which sensor(s) has(have) to be activated in order to measure the respect- ive current parameter value and store it in the memory.
7. Transponder according to one of the preceding claims, characterized in that the sensor or one of the sensors is a temperature sensor.
8. Transponder according to one of the preceding Claims 1-6, character¬ ized in that the sensor or one of the sensors is a pressure sensor.
9. Transponder according to one of the preceding Claims 1-6, character¬ ized in that the sensor or one of the sensors is a humidity sensor.
10. Transponder according to one of the preceding Claims 1-6, character¬ ized in that the sensor or one of the sensors is an electrochemical sensor for measuring, for example, pH, glucose content or the like.
11. Transponder according to one of the preceding Claims 1-6, character¬ ized in that the sensor or one of the sensors is a movement sensor.
*****
PCT/NL1996/000375 1995-09-26 1996-09-26 Transponder containing measuring circuit WO1997012258A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU71470/96A AU7147096A (en) 1995-09-26 1996-09-26 Transponder containing measuring circuit

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL1001295 1995-09-26
NL1001295A NL1001295C2 (en) 1995-09-26 1995-09-26 Transponder with measuring circuit.

Publications (1)

Publication Number Publication Date
WO1997012258A1 true WO1997012258A1 (en) 1997-04-03

Family

ID=19761632

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NL1996/000375 WO1997012258A1 (en) 1995-09-26 1996-09-26 Transponder containing measuring circuit

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AU (1) AU7147096A (en)
NL (1) NL1001295C2 (en)
WO (1) WO1997012258A1 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2763127A1 (en) * 1997-05-12 1998-11-13 France Etat DISPOSABLE PROBE THERMOMETER
NL1009175C2 (en) * 1998-05-15 1999-11-16 Leuven K U Res & Dev Apparatus and method for observing and collecting quantities of mobile bodies.
WO2000043802A1 (en) * 1999-01-21 2000-07-27 Siemens Aktiengesellschaft Configuration for producing a response signal carrying a piece of information and method for the remote inquiry of such a configuration
GB2425691A (en) * 2005-04-29 2006-11-01 Hewlett Packard Development Co Activating an RF transponder sensor to make and hold measurements
DE102005037582A1 (en) * 2005-08-09 2007-02-22 Siemens Ag Locatable and energy self-sufficient backscatter transponder for the acquisition of measured variables
DE102006022933A1 (en) * 2006-05-15 2007-11-22 Bpw Bergische Achsen Kg Transponder and reader linear distance measuring method, involves evaluating field strength of signal response by forming received signal strength indicator-value, and generating linear distance information from indicator-value
FR2915909A1 (en) * 2007-05-11 2008-11-14 Thurot Philippe Jean Louis Waste e.g. municipal solid waste, sorting-composting installation for producing waste compost, has recycling unit resending neutralized liquor and dust loaded liquor to compaction case/tube, where sent liquor is controllable

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US4033186A (en) * 1976-08-06 1977-07-05 Don Bresie Method and apparatus for down hole pressure and temperature measurement
US4109527A (en) * 1976-10-26 1978-08-29 The Dow Chemical Company Device for measuring pH and temperature of a liquid, which includes a memory
WO1984000869A1 (en) * 1982-08-09 1984-03-01 Cornell Res Foundation Inc Remote passive identification system
EP0301127A1 (en) * 1987-07-31 1989-02-01 Texas Instruments Deutschland Gmbh Transponder arrangement
WO1993008451A1 (en) * 1991-10-18 1993-04-29 Sensitech, Inc. Disposable electronic monitor device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4033186A (en) * 1976-08-06 1977-07-05 Don Bresie Method and apparatus for down hole pressure and temperature measurement
US4109527A (en) * 1976-10-26 1978-08-29 The Dow Chemical Company Device for measuring pH and temperature of a liquid, which includes a memory
WO1984000869A1 (en) * 1982-08-09 1984-03-01 Cornell Res Foundation Inc Remote passive identification system
EP0301127A1 (en) * 1987-07-31 1989-02-01 Texas Instruments Deutschland Gmbh Transponder arrangement
US5053774A (en) * 1987-07-31 1991-10-01 Texas Instruments Deutschland Gmbh Transponder arrangement
WO1993008451A1 (en) * 1991-10-18 1993-04-29 Sensitech, Inc. Disposable electronic monitor device

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2763127A1 (en) * 1997-05-12 1998-11-13 France Etat DISPOSABLE PROBE THERMOMETER
EP0878696A1 (en) * 1997-05-12 1998-11-18 Etat-Francais représenté par le Délégué Général pour L'Armement Thermometer with a disposable probe
NL1009175C2 (en) * 1998-05-15 1999-11-16 Leuven K U Res & Dev Apparatus and method for observing and collecting quantities of mobile bodies.
EP0956811A1 (en) * 1998-05-15 1999-11-17 K.U. Leuven Research & Development Device and method for monitoring and collecting data from mobile bodies
WO2000043802A1 (en) * 1999-01-21 2000-07-27 Siemens Aktiengesellschaft Configuration for producing a response signal carrying a piece of information and method for the remote inquiry of such a configuration
GB2425691A (en) * 2005-04-29 2006-11-01 Hewlett Packard Development Co Activating an RF transponder sensor to make and hold measurements
DE102005037582A1 (en) * 2005-08-09 2007-02-22 Siemens Ag Locatable and energy self-sufficient backscatter transponder for the acquisition of measured variables
DE102006022933A1 (en) * 2006-05-15 2007-11-22 Bpw Bergische Achsen Kg Transponder and reader linear distance measuring method, involves evaluating field strength of signal response by forming received signal strength indicator-value, and generating linear distance information from indicator-value
FR2915909A1 (en) * 2007-05-11 2008-11-14 Thurot Philippe Jean Louis Waste e.g. municipal solid waste, sorting-composting installation for producing waste compost, has recycling unit resending neutralized liquor and dust loaded liquor to compaction case/tube, where sent liquor is controllable

Also Published As

Publication number Publication date
AU7147096A (en) 1997-04-17
NL1001295C2 (en) 1997-03-28

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