EP0538624A1 - Arrangement for galvanically isolated transmission of measuring and control signals - Google Patents

Arrangement for galvanically isolated transmission of measuring and control signals Download PDF

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Publication number
EP0538624A1
EP0538624A1 EP92115976A EP92115976A EP0538624A1 EP 0538624 A1 EP0538624 A1 EP 0538624A1 EP 92115976 A EP92115976 A EP 92115976A EP 92115976 A EP92115976 A EP 92115976A EP 0538624 A1 EP0538624 A1 EP 0538624A1
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EP
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Prior art keywords
pulse
voltage
capacitor
charging
measuring
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EP92115976A
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German (de)
French (fr)
Inventor
Günter von zur Gathen
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ABB Training Center GmbH and Co KG
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Hartmann and Braun AG
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    • G—PHYSICS
    • G08—SIGNALLING
    • G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
    • G08C17/00—Arrangements for transmitting signals characterised by the use of a wireless electrical link
    • G08C17/04—Arrangements for transmitting signals characterised by the use of a wireless electrical link using magnetically coupled devices

Definitions

  • the invention relates to an arrangement for the isolated transmission of measurement and control signals between a transducer and an evaluation circuit via a magnetic transmitter according to the preamble of the claim.
  • a device for transmitting measurement signals in which measurement signals in digital form are galvanically decoupled from an active measurement sensor to a measuring device and signals from the measuring device to the measurement sensor - preferably over greater distances - are transmitted, which at the same time Power supply to the sensor.
  • the edge-coded signals from the measuring device to the sensor are used as a clock signal.
  • the clock signals sent from the measuring device to the measuring sensor are voltage-dependent, while the signals from the measuring sensor to the measuring device are connected in a current-dependent manner.
  • the measuring device and transducer are coupled to each other via a transmitter and a two-wire line. Circuit means for coding or decoding the measurement signal are always required.
  • DE-PS 29 49 075 shows an arrangement for electrically isolated transmission of measurement signals, in which charging pulses induced in the secondary winding of a transformer feed a charging circuit with a diode and a capacitor.
  • the charging voltage at the capacitor serves as the supply voltage for a pulse distance modulator.
  • DE-OS 27 33 875 describes remote feeding of remote receivers of remote control devices which are controlled in time-division multiplex cycles.
  • a power supply pulse is transmitted in the first part of the cycle, while the information pulses are transmitted in the remaining cycle time.
  • the power supply pulse also serves to synchronize the transmitter and receiver.
  • the object of the invention is to provide an arrangement which is suitable for the floating transmission of measurement and control signals with a transmitter and which cooperates with a pulse modulator on the signal-generating side, which receives its supply voltage from pulse groups from the signal processing side of the transmitter.
  • the circuitry for coding and decoding the measurement signal is to be minimized on the condition that the time period for the transmission of the individual pulse groups is shorter than the time period for the transmission of the measurement signals.
  • a triggerable pulse duration modulator As a pulse modulator for converting a DC voltage into a pulse, the pulse duration of which corresponds to the amplitude of the measurement voltage, a triggerable pulse duration modulator is suitable, the precise functioning of which is explained in patent application DE 39 00 179.
  • a capacitor on the secondary side of a transformer continuously supplies the pulse modulator with the necessary supply voltage.
  • the capacitor draws its charge in such a way that an AC voltage in the form of charge pulses is applied to the primary winding of the transformer, which a pulse generator generates from an auxiliary voltage. If the current consumption of the pulse modulator is sufficiently small, only a few charge pulses are sufficient to charge the capacitor to a voltage level necessary for the operation of the pulse modulator.
  • the time during which the pulse generator does not emit any charge pulses is used to induce a measurement-dependent pulse generated by the pulse modulator from the secondary side to an evaluation circuit on the primary side of the transmitter.
  • the evaluation circuit determines the duration of the measurement pulses, which is a measure of the amplitude of the DC voltage supplied to the pulse modulator.
  • the direct voltage U M emitted by a sensor is fed to a pulse modulator PDM, which converts the respective amplitude value of U M into a measuring pulse S2, the duration of which is proportional to the amplitude value of U M and as the measuring time T M referred to as.
  • the measuring pulse S2 is at the output A2 of the Pulse modulator PDM available.
  • a line 14 connects the output A2 to the switching input of a switch 12, which can be a semiconductor switch.
  • the pulse modulator PDM also has a voltage input 4, a trigger input E2, an input 2 for a reference voltage U0 and an input 3 for a reference voltage U REF .
  • a triggerable pulse duration modulator as described in German patent application DE 39 00 179 is used as the pulse modulator PDM.
  • the start of a conversion of the direct voltage U M into a measuring pulse S2 is triggered by a pulse at the trigger input E2.
  • the three input voltages U0, U REF and U M are successively applied to the pulse modulator PDM via internal changeover switches.
  • the reference voltage Uimp which is determined in the exemplary embodiment by the potential of the reference point 18, is used to generate a zero pulse for establishing the zero point.
  • the modulation sensitivity of the pulse modulator PDM is measured, ie the measuring time T M is determined as a function of U REF.
  • a connection of the capacitor C1 is at the voltage input 4 of the pulse modulator PDM; its charging voltage continuously supplies the pulse modulator PDM with the necessary supply voltage and feeds a reference voltage source, not shown, at which the input voltage U REF is set.
  • the capacitor C1 obtains its charge from pulse groups, the charge pulses P, which are fed into the primary winding 9 of the transformer U, the secondary winding 10 of which is connected to a terminal of the capacitor C1 via a rectifier D1.
  • a capacitor C2 is also charged with the charging current pulses P induced in the secondary winding 10 via a rectifier D2.
  • the secondary side 10 of the transformer U, the pulse modulator PDM, the switch 12 and the capacitor C1 are each connected to a reference point 18 with one connection.
  • a pulse generator I with a voltage input 5, with a pulse output 6 and with a trigger input 7, and an evaluation circuit 15 with a voltage input 8, with a trigger input E1, further trigger inputs E N and with a pulse output A1.
  • the pulse generator I, the evaluation circuit 15 and the primary winding 9 of the transformer U are each connected with a connection to a reference point 11 which differs in potential from the reference point 18 on the secondary side of the transformer.
  • An auxiliary voltage U H supplies the pulse generator I at its voltage input 5 and the evaluation circuit 15 at the voltage input 8 with the required operating voltage.
  • FIG. 1 The mode of operation of the exemplary embodiment shown in FIG. 1 is explained on the basis of the pulse diagram shown in FIG. 2. It shows the charging current pulses P present at the output 6 of the pulse generator I in relation to the measuring pulse S2 generated by the pulse modulator PDM at the output A2 and the control signal S1 induced in the primary winding 9 and fed via a line 17 to the trigger input E1 of the evaluation circuit 15.
  • the evaluation circuit 15 activates at intervals T of, for example, 100 ms via the output A1, the line 16 and the trigger input 7, the pulse generator I, which feeds charging current pulses P into the primary winding 9 of the transformer U for the period t of, for example, 10 ms.
  • the upper curve in FIG. 2 shows the time course of the charging current pulses P, which are repeated cyclically at a distance T.
  • the time T - t between the end of the last pulse and the beginning of the new pulse is used for the measured value transmission in such a way that a measured value-dependent signal of the pulse modulator PDM is transmitted from the secondary side to the primary side of the transmitter U.
  • the evaluation circuit 15 detects this signal and evaluates its time dependence.
  • the pulse modulator PDM is triggered at the input E2 with the first pulse P1 of the charging current pulses P transmitted to the secondary side; a line 13 connects the free connection of the secondary winding 10 to the input E2.
  • the pulse modulator PDM switches to measuring mode and delivers the measuring pulse S2 at the output A2, the length of which is the measuring time T M , which is a measure of the amplitude of the direct voltage U M to be measured.
  • the middle curve in FIG. 2 shows the time course of a measuring pulse S2 at the output A2 of the pulse modulator PDM.
  • the voltage at output A2 changes from, for example, 10 volts to zero volts.
  • This voltage jump reaches the switching input of the switch 12 via a line 14, which becomes conductive so that the capacitor C2 can discharge via the secondary winding 10.
  • This discharging process causes a control signal S1 in the primary winding 9, which reaches the trigger input E1 of the evaluation circuit 15 via a line 17.
  • the lower curve in FIG. 2 shows the time course of the control signal S1 at the trigger input E1; the control signal S1 to appear after the time T M to the end of the measuring pulse S2, with its time interval depends on the beginning of the measuring time T M of the amplitude of the DC voltage U M.
  • the evaluation circuit 15 determines the time that elapses between the first pulse P1 of the charging current pulses and the arrival of the control signal S1 at its trigger input E1. This time corresponds to the measuring time T M and is a measure of the amplitude of the DC voltage U M to be determined.
  • timing counting circuits are suitable in which the measurement is based on the counting of unit pulses. Timer functions of microcontrollers can also be used as a counter circuit.
  • the evaluation circuit 15 contains a time circuit, not shown, which determines the duration t of the charging current pulses P in accordance with the relationship t ⁇ T M ⁇ T. This condition ensures that a sufficient number of charging current pulses for the maintenance of the charging of the capacitors C1 and C2 is emitted from the pulse generator I to the primary winding and that, on the other hand, the time period between the charging current pulses is sufficiently long for the measured value transmission.
  • the evaluation circuit is equipped with further trigger inputs E n , which are prepared for receiving further control signals.
  • the arrangement shown is thus suitable for processing multichannel measuring arrangements, only one evaluation circuit with n counting functions being required for n measuring channels. If all n measuring arrangements are supplied with the same charging current pulses, a pulse generator with an auxiliary voltage is sufficient.
  • FIG. 3 shows a circuit variant of the arrangement according to FIG. 1, in which the capacitor C2 draws its charge via a tap 19 of the secondary winding 10. Via the tap 19, the control pulse S1 generates a larger pulse amplitude as a result of the more favorable transmission ratio of the transformer U in the primary winding 9, so that the control pulse S1 can be detected more easily.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Arrangements For Transmission Of Measured Signals (AREA)

Abstract

The invention relates to an arrangement for the floating transmission of measurement and control signals between a measurement converter and an evaluation circuit, via a magnetic transformer, in the case of which measurement signals are transmitted in one direction from the measurement converter to the evaluation circuit, and the supply voltage which is required to operate the measurement converter is transmitted in the other direction. A pulse modulator is used as the measurement converter, to which a DC voltage is supplied in order to produce voltages pulses whose pulse duration depends on the amplitude of the DC voltage. A pulse transmitter (I) produces charging-current pulses (P), which are supplied to the primary winding (9) of the transformer (Ü), at time intervals (T) and with a predetermined time duration (t). The charging-current pulses (P) which are induced in the secondary winding (10) of the transformer (Ü) supply a first charging circuit, having a rectifier (D1) and a capacitor (C1), as well as a second charging circuit, having a rectifier (D2) and a capacitor (C2). The charging voltage on the first capacitor (C1) is used as the supply voltage for the pulse modulator (PDM). <IMAGE>

Description

Die Erfindung betrifft Anordnung zur potentialgetrennten Übertragung von Meß- und Steuersignalen zwischen einem Meßumformer und einer Auswerteschaltung über einen magnetischen Übertrager nach dem Oberbegriff des Patentanspruches.The invention relates to an arrangement for the isolated transmission of measurement and control signals between a transducer and an evaluation circuit via a magnetic transmitter according to the preamble of the claim.

Aus der DE-OS 34 10 752 ist eine Vorrichtung zur Übertragung von Meßsignalen bekannt, bei dem von einem aktiven Meßwertaufnehmer Meßsignale in digitaler Form galvanisch entkoppelt zu einem Meßgerät und Signale vom Meßgerät zum Meßwertaufnehmer - vorzugsweise über größere Entfernungen - übertragen werden, die zugleich zur Spannungsversorgung des Meßwertaufnehmer dienen. Die flanken-codierten Signale vom Meßgerät zum Meßwertaufnehmer werden als Taktsignal verwendet. Zur Trennung der unterschiedlichen Signale sind die vom Meßgerät zum Meßwertaufnehmer gesandten Taktsignale spannungsabhängig, während die Signale vom Meßwertaufnehmer zum Meßgerät stromabhängig geschaltet sind. Meßgerät und Meßwertaufnehmer sind über je einen Übertrager und eine zweiadrige Leitung miteinander gekoppelt. Hierbei sind stets Schaltungsmittel zur Codierung oder Decodierung des Meßsignales efforderlich.From DE-OS 34 10 752 a device for transmitting measurement signals is known, in which measurement signals in digital form are galvanically decoupled from an active measurement sensor to a measuring device and signals from the measuring device to the measurement sensor - preferably over greater distances - are transmitted, which at the same time Power supply to the sensor. The edge-coded signals from the measuring device to the sensor are used as a clock signal. To separate the different signals, the clock signals sent from the measuring device to the measuring sensor are voltage-dependent, while the signals from the measuring sensor to the measuring device are connected in a current-dependent manner. The measuring device and transducer are coupled to each other via a transmitter and a two-wire line. Circuit means for coding or decoding the measurement signal are always required.

Aus der DE-OS 37 26 837 ist eine Anordnung zur zweiseitigen potentialgetrennten Übertragung von Signalen über einen Trennübertrager bekannt, bei der von der signalverarbeitenden Seite Steuersignale über den Trennübertrager auf die signalerzeugende Seite übertragen werden, die die analogen Informationssignale in einen codierten Impuls umsetzen. Zur Signalübertragung werden Modulationsverfahren mit Modulator und Demodulator eingesetzt, wobei in einer Richtung gleichzeitig Energie zur Versorgung der signalverarbeitenden Schaltungsteile mit übertragen werden.From DE-OS 37 26 837 an arrangement for double-sided electrically isolated transmission of signals via an isolating transformer is known, in which control signals are transmitted from the signal processing side via the isolating transformer to the signal-generating side, which convert the analog information signals into a coded pulse. Modulation methods with modulator and demodulator are used for signal transmission, energy being simultaneously transmitted in one direction to supply the signal-processing circuit parts.

Die DE-PS 29 49 075 zeigt eine Anordnung zur potentialgetrennten Übertragung von Meßsignalen, bei der in der Sekundärwicklung eines Übertragers induzierte Ladepulse eine Ladeschaltung mit einer Diode und einem Kondensator speisen. Die Ladespannung am Kondensator dient als Speisespannung für einen Pulsabstandsmodulator.DE-PS 29 49 075 shows an arrangement for electrically isolated transmission of measurement signals, in which charging pulses induced in the secondary winding of a transformer feed a charging circuit with a diode and a capacitor. The charging voltage at the capacitor serves as the supply voltage for a pulse distance modulator.

In der DE-OS 27 33 875 ist eine Fernspeisung von entfernt liegenden Empfängern von Fernsteuereinrichtungen beschrieben, die in Zeitmultiplex-Zyklen gesteuert werden. Ein Stromversorgungsimpuls wird im ersten Teil des Zyklus übertragen, während die Informationsimpulse in der restlichen Zykluszeit zur Übertragung kommen. Der Stromversorgungsimpuls dient auch zur Synchronisation von Sender und Empfänger.DE-OS 27 33 875 describes remote feeding of remote receivers of remote control devices which are controlled in time-division multiplex cycles. A power supply pulse is transmitted in the first part of the cycle, while the information pulses are transmitted in the remaining cycle time. The power supply pulse also serves to synchronize the transmitter and receiver.

Ausgehend von der in der DE-OS 37 26 837 beschriebenen Übertragungsanordnung besteht die Aufgabe der Erfindung darin, eine Anordnung zu schaffen, die zur potentialfreien Übertragung von Meß- und Steuersignalen mit einem Übertrager geeignet ist und die auf der signalerzeugenden Seite mit einem Pulsmodulator zusammenarbeitet, der seine Speisespannung aus Impulsgruppen von der signalverarbeitenden Seite des Übertragers erhält. Der Schaltungsaufwand zur Codierung und Decodierung des Meßsignales ist zu minimieren unter der Bedingung, daß die Zeitdauer für die Übertragung der einzelnen Impulsgruppen kleiner als die Zeitdauer für die Übertragung der Meßsignale ist.Starting from the transmission arrangement described in DE-OS 37 26 837, the object of the invention is to provide an arrangement which is suitable for the floating transmission of measurement and control signals with a transmitter and which cooperates with a pulse modulator on the signal-generating side, which receives its supply voltage from pulse groups from the signal processing side of the transmitter. The circuitry for coding and decoding the measurement signal is to be minimized on the condition that the time period for the transmission of the individual pulse groups is shorter than the time period for the transmission of the measurement signals.

Diese Aufgabe wird in Verbindung mit den Merkmalen des Oberbegriffes erfindungsgemäß durch die im Kennzeichen des Anspruches 1 angegebenen Merkmale gelöst.This object is achieved in connection with the features of the preamble according to the invention by the features specified in the characterizing part of claim 1.

Als Pulsmodulator zur Umsetzung einer Gleichspannung in einen Impuls, dessen Pulsdauer der Amplitude der Meßspannung entspricht, eignet sich ein triggerbarer Pulsdauermodulator, dessen genaue Funktionsweise in der Patentanmeldung DE 39 00 179 erläutert ist.As a pulse modulator for converting a DC voltage into a pulse, the pulse duration of which corresponds to the amplitude of the measurement voltage, a triggerable pulse duration modulator is suitable, the precise functioning of which is explained in patent application DE 39 00 179.

Ein Kondensator auf der Sekundärseite eines Übertragers versorgt den Pulsmodulator kontinuierlich mit der notwendigen Speisespannung. Der Kondensator bezieht seine Ladung derart, daß die Primärwicklung des Übertragers mit einer Wechselspannung in der Form von Ladungsimpulsen beaufschlagt wird, die ein Impulsgeber aus einer Hilfspannung generiert. Ist der Stromverbrauch des Pulsmodulators ausreichend klein, dann genügen nur wenige Ladungsimpulse, um den Kondensator auf eine für den Betrieb des Pulsmodulators notwendigen Spannungspegel aufzuladen.A capacitor on the secondary side of a transformer continuously supplies the pulse modulator with the necessary supply voltage. The capacitor draws its charge in such a way that an AC voltage in the form of charge pulses is applied to the primary winding of the transformer, which a pulse generator generates from an auxiliary voltage. If the current consumption of the pulse modulator is sufficiently small, only a few charge pulses are sufficient to charge the capacitor to a voltage level necessary for the operation of the pulse modulator.

Die Zeit, in der der Impulsgeber keine Ladungsimpulse abgibt, wird genutzt, einen vom Pulsmodulator erzeugten meßwertabhängigen Impuls von der Sekundärseite zu einer Auswerteschaltung auf der Primärseite des Übertragers zu induzieren. Die Auswerteschaltung ermittelt die zeitliche Dauer der Meßimpulse, die ein Maß für die Amplitude der dem Pulsmodulator zugeführten Gleichspannung ist.The time during which the pulse generator does not emit any charge pulses is used to induce a measurement-dependent pulse generated by the pulse modulator from the secondary side to an evaluation circuit on the primary side of the transmitter. The evaluation circuit determines the duration of the measurement pulses, which is a measure of the amplitude of the DC voltage supplied to the pulse modulator.

Die Erfindung wird anhand eines in der Zeichnung dargestellten Ausführungsbeispieles näher erläutert.The invention is explained in more detail using an exemplary embodiment shown in the drawing.

Es zeigen

Fig. 1
das Blockschaltbild einer Anordnung zur potentialgetrennten Übertragung von Meß- und Steuersignalen mit einem Übertrager und
Fig. 2
den zeitlichen Verlauf der in der Anordnung nach Fig. 1 auftretenden Ladungs-, Meß- und Steuerimpulse und
Fig. 3
eine Schaltungsvariante der Anordnung nach Fig. 1.
Show it
Fig. 1
the block diagram of an arrangement for electrically isolated transmission of measurement and control signals with a transformer and
Fig. 2
the time course of the charge, measurement and control pulses occurring in the arrangement of FIG. 1 and
Fig. 3
2 shows a circuit variant of the arrangement according to FIG. 1.

In der Anordnung nach Fig. 1 wird die von einem nicht dargestellten Sensor abgegebene Gleichspannung UM einem Pulsmodulator PDM zugeführt, der den jeweiligen Amplitudenwert von UM in einen Meßimpuls S2 umsetzt, dessen Dauer proportional zum Amplitudenwert von UM ist und als Meßzeit TM bezeichnet wird. Der Meßimpuls S2 steht am Ausgang A2 des Pulsmodulators PDM zur Verfügung. Eine Leitung 14 verbindet den Ausgang A2 mit dem Schalteingang eines Schalters 12, der ein Halbleiterschalter sein kann. Der Pulsmodulator PDM besitzt ferner einen Spannungseingang 4, einen Triggereingang E2, einen Eingang 2 für eine Bezugsspannung U₀ sowie einen Eingang 3 für eine Referenzspannung UREF.In the arrangement according to FIG. 1, the direct voltage U M emitted by a sensor (not shown) is fed to a pulse modulator PDM, which converts the respective amplitude value of U M into a measuring pulse S2, the duration of which is proportional to the amplitude value of U M and as the measuring time T M referred to as. The measuring pulse S2 is at the output A2 of the Pulse modulator PDM available. A line 14 connects the output A2 to the switching input of a switch 12, which can be a semiconductor switch. The pulse modulator PDM also has a voltage input 4, a trigger input E2, an input 2 for a reference voltage U₀ and an input 3 for a reference voltage U REF .

Als Pulsmodulator PDM wird ein triggerbarer Pulsdauermodulator verwendet, wie er in der deutschen Patentanmeldung DE 39 00 179 beschrieben ist.A triggerable pulse duration modulator as described in German patent application DE 39 00 179 is used as the pulse modulator PDM.

Der Start einer Umwandlung der Gleichspannung UM in ein Meßimpuls S2 wird durch einen Puls am Triggereingang E2 ausgelöst. Über interne Umschalter werden dem Pulsmodulator PDM nacheinander die drei Eingangsspannungen U₀, UREF und UM aufgeschaltet. Zur Erzeugung eines Nullimpulses für die Festlegung des Nullpunktes dient die Bezugsspannung U₀, die im Ausführungsbeispiel durch das Potential des Bezugspunkes 18 bestimmt ist. Mit Hilfe der Referenzspannung UREF wird die Aussteuer-Empfindlichkeit des Pulsmodulators PDM gemessen, d.h. es wird die Meßzeit TM in Abhängigkeit von UREF ermittelt.The start of a conversion of the direct voltage U M into a measuring pulse S2 is triggered by a pulse at the trigger input E2. The three input voltages U₀, U REF and U M are successively applied to the pulse modulator PDM via internal changeover switches. The reference voltage Uimp, which is determined in the exemplary embodiment by the potential of the reference point 18, is used to generate a zero pulse for establishing the zero point. With the aid of the reference voltage U REF, the modulation sensitivity of the pulse modulator PDM is measured, ie the measuring time T M is determined as a function of U REF.

Ein Anschluß des Kondensators C1 liegt am Spannungseingang 4 des Pulsmodulators PDM; seine Ladespannung versorgt den Pulsmodulator PDM kontinuierlich mit der notwendigen Speisespannung und speist eine nicht dargestellte Referenzspannungsquelle, an der die Eingangsspannung UREF eingestellt wird. Der Kondensator C1 bezieht seine Ladung aus Impulsgruppen, den Ladungsimpulsen P, die in die Primärwicklung 9 des Übertrager Ü eingespeist werden, dessen Sekundärwicklung 10 über einen Gleichrichter D1 mit einem Anschluß des Kondensators C1 verbunden ist.A connection of the capacitor C1 is at the voltage input 4 of the pulse modulator PDM; its charging voltage continuously supplies the pulse modulator PDM with the necessary supply voltage and feeds a reference voltage source, not shown, at which the input voltage U REF is set. The capacitor C1 obtains its charge from pulse groups, the charge pulses P, which are fed into the primary winding 9 of the transformer U, the secondary winding 10 of which is connected to a terminal of the capacitor C1 via a rectifier D1.

Ein Kondensator C2 wird gleichfalls mit den in der Sekundärwicklung 10 induzierten Ladestrompulsen P über einen Gleichrichter D2 aufgeladen.A capacitor C2 is also charged with the charging current pulses P induced in the secondary winding 10 via a rectifier D2.

Die Sekundärseite 10 des Übertrager Ü, der Pulsmodulator PDM, der Schalter 12 und der Kondensator C1 sind jeweils mit einem Anschluß gemeinsam an einen Bezugspunkt 18 angeschlossen.The secondary side 10 of the transformer U, the pulse modulator PDM, the switch 12 and the capacitor C1 are each connected to a reference point 18 with one connection.

Auf der Primärseite des Übertragers Ü befinden sich ein Impulsgeber I mit einem Spannungseingang 5, mit einem Impulsausgang 6 und mit einem Triggereingang 7 sowie eine Auswerteschaltung 15 mit einem Spannungseingang 8, mit einem Triggereingang E1, weiteren Triggereingängen EN und mit einem Impulsausgang A1.On the primary side of the transformer Ü there is a pulse generator I with a voltage input 5, with a pulse output 6 and with a trigger input 7, and an evaluation circuit 15 with a voltage input 8, with a trigger input E1, further trigger inputs E N and with a pulse output A1.

Der Impulsgeber I, die Auswerteschaltung 15 und die Primärwicklung 9 des Übertrager Ü sind jeweils mit einem Anschluß gemeinsam an einen Bezugspunkt 11 angeschlossen, der sich potentialmäßig vom Bezugspunkt 18 auf der Sekundärseite des Übertragers unterscheidet.The pulse generator I, the evaluation circuit 15 and the primary winding 9 of the transformer U are each connected with a connection to a reference point 11 which differs in potential from the reference point 18 on the secondary side of the transformer.

Eine Hilfsspannung UH versorgt den Impulsgeber I an seinem Spannungseingang 5 und die Auswerteschaltung 15 am Spannungseingang 8 mit der erforderlichen Betriebsspannung.An auxiliary voltage U H supplies the pulse generator I at its voltage input 5 and the evaluation circuit 15 at the voltage input 8 with the required operating voltage.

Die Funktionsweise des in Fig. 1 gezeigten Ausführungsbeispieles wird anhand des in Fig. 2 dargestellten Pulsdiagrammes erläutert. Es zeigt die am Ausgang 6 des Impulsgebers I anstehenden Ladestrompulse P im zeitlichen Bezug zu dem vom Pulsmodulator PDM am Ausgang A2 erzeugten Meßimpuls S2 und das in der Primärwicklung 9 induzierte und über eine Leitung 17 dem Triggereingang E1 der Auswerteschaltung 15 zugeführte Steuersignal S1.The mode of operation of the exemplary embodiment shown in FIG. 1 is explained on the basis of the pulse diagram shown in FIG. 2. It shows the charging current pulses P present at the output 6 of the pulse generator I in relation to the measuring pulse S2 generated by the pulse modulator PDM at the output A2 and the control signal S1 induced in the primary winding 9 and fed via a line 17 to the trigger input E1 of the evaluation circuit 15.

Die Auswerteschaltung 15 aktiviert in zeitlichen Abständen T von beispielsweise 100 ms über den Ausgang A1, die Leitung 16 und den Triggereingang 7 den Impulsgeber I, der für die Zeitdauer t von beispielsweise 10 ms Ladestrompulse P in die Primärwicklung 9 des Übertrager Ü speist. Die obere Kurve in Fig. 2 zeigt den zeitlichen Verlauf der Ladestrompulse P, die sich im Abstand T zyklisch wiederholen.The evaluation circuit 15 activates at intervals T of, for example, 100 ms via the output A1, the line 16 and the trigger input 7, the pulse generator I, which feeds charging current pulses P into the primary winding 9 of the transformer U for the period t of, for example, 10 ms. The upper curve in FIG. 2 shows the time course of the charging current pulses P, which are repeated cyclically at a distance T.

Die Zeit T - t zwischen dem Ende des letzten Pulses und dem Anfang des neuen Pulses wird für die Meßwertübertragung genutzt derart, daß ein meßwertabhängiges Signal des Pulsmodulators PDM von der Sekundärseite auf die Primärseite des Übertrager Ü übertragen wird. Die Auswerteschaltung 15 erfaßt dieses Signal und wertet dessen Zeitabhängigkeit aus.The time T - t between the end of the last pulse and the beginning of the new pulse is used for the measured value transmission in such a way that a measured value-dependent signal of the pulse modulator PDM is transmitted from the secondary side to the primary side of the transmitter U. The evaluation circuit 15 detects this signal and evaluates its time dependence.

Mit dem ersten Puls P1 der auf die Sekundärseite übertragenen Ladestrompulse P wird der Pulsmodulator PDM am Eingang E2 getriggert; eine Leitung 13 verbindet den freien Anschluß der Sekundärwicklung 10 mit dem Eingang E2. Der Pulsmodulator PDM schaltet auf Meßbetrieb und liefert am Ausgang A2 den Meßimpuls S2, dessen Länge die Meßzeit TM ist, die ein Maß für die Amplitude der zu messenden Gleichspannung UM darstellt. Die mittlere Kurve in Fig. 2 zeigt den zeitlichen Verlauf eines Meßimpulses S2 am Ausgang A2 des Pulsmodulators PDM.The pulse modulator PDM is triggered at the input E2 with the first pulse P1 of the charging current pulses P transmitted to the secondary side; a line 13 connects the free connection of the secondary winding 10 to the input E2. The pulse modulator PDM switches to measuring mode and delivers the measuring pulse S2 at the output A2, the length of which is the measuring time T M , which is a measure of the amplitude of the direct voltage U M to be measured. The middle curve in FIG. 2 shows the time course of a measuring pulse S2 at the output A2 of the pulse modulator PDM.

Am Ende der Meßzeit TM ändert sich die Spannung am Ausgang A2 von beispielsweise 10 Volt in Null Volt. Dieser Spannungsprung gelangt über eine Leitung 14 an den Schalteingang des Schalters 12. Dieser wird leitend, so daß sich der Kondensator C2 über die Sekundärwicklung 10 entladen kann. Dieser Entladevorgang ruft in der Primärwicklung 9 ein Steuersignal S1 hervor, welches über eine Leitung 17 an den Triggereingang E1 der Auswerteschaltung 15 gelangt.At the end of the measuring time T M , the voltage at output A2 changes from, for example, 10 volts to zero volts. This voltage jump reaches the switching input of the switch 12 via a line 14, which becomes conductive so that the capacitor C2 can discharge via the secondary winding 10. This discharging process causes a control signal S1 in the primary winding 9, which reaches the trigger input E1 of the evaluation circuit 15 via a line 17.

Die untere Kurve in Fig. 2 zeigt den zeitlichen Verlauf des Steuersignales S1 am Triggereingang E1; das Steuersignal S1 erscheint nach Ablauf der Zeit TM mit dem Ende des Meßimpulses S2, wobei sein zeitlicher Abstand zum Beginn der Meßzeit TM von der Amplitude der Gleichspannung UM abhängt.The lower curve in FIG. 2 shows the time course of the control signal S1 at the trigger input E1; the control signal S1 to appear after the time T M to the end of the measuring pulse S2, with its time interval depends on the beginning of the measuring time T M of the amplitude of the DC voltage U M.

Die Auswerteschaltung 15 ermittelt die Zeit, die vergeht zwischen dem ersten Puls P1 der Ladestrompulse und dem Eintreffen des Steuersignales S1 an seinem Triggereingang E1. Diese Zeit entspricht der Meßzeit TM und ist ein Maß für die zu bestimmende Amplitude der Gleichspannung UM. Für die Zeitmessung sind Zählschaltungen geeignet, bei denen die Messung auf der Auszählung von Einheitsimpulsen beruht. Es können auch Timerfunktionen von Mikrocontrollern als Zählschaltung verwendet werden.The evaluation circuit 15 determines the time that elapses between the first pulse P1 of the charging current pulses and the arrival of the control signal S1 at its trigger input E1. This time corresponds to the measuring time T M and is a measure of the amplitude of the DC voltage U M to be determined. For timing counting circuits are suitable in which the measurement is based on the counting of unit pulses. Timer functions of microcontrollers can also be used as a counter circuit.

Die Auswerteschaltung 15 enthält eine nicht dargestellte Zeitschaltung, die die Zeitdauer t der Ladestrompulse P entsprechend der Beziehung t < TM < T festlegt. Diese Bedingung stellt sicher, daß eine für die Aufrechterhaltung der Ladung der Kondensatoren C1 und C2 ausreichende Anzahl von Ladestrompulsen vom Impulsgeber I an die Primärwicklung abgegeben wird und daß andererseits die Zeitspanne zwischen den Ladestrompulsen für die Meßwertübertragung ausreichend bemessen ist.The evaluation circuit 15 contains a time circuit, not shown, which determines the duration t of the charging current pulses P in accordance with the relationship t <T M <T. This condition ensures that a sufficient number of charging current pulses for the maintenance of the charging of the capacitors C1 and C2 is emitted from the pulse generator I to the primary winding and that, on the other hand, the time period between the charging current pulses is sufficiently long for the measured value transmission.

Die Auswerteschaltung ist mit weiteren Triggereingängen En ausgestattet, die für die Aufnahme weiterer Steuersignale vorbereitet sind. Die gezeigte Anordnung eignet sich damit für die Verarbeitung mehrkanaliger Meßanordnungen, wobei für n Meßkanäle nur eine Auswerteschaltung mit n Zählfunktionen erforderlich ist. Werden alle n Meßanordnungen mit den gleichen Ladestrompulsen gespeist, so genügt ein Impulsgeber mit einer Hilfspannung.The evaluation circuit is equipped with further trigger inputs E n , which are prepared for receiving further control signals. The arrangement shown is thus suitable for processing multichannel measuring arrangements, only one evaluation circuit with n counting functions being required for n measuring channels. If all n measuring arrangements are supplied with the same charging current pulses, a pulse generator with an auxiliary voltage is sufficient.

Fig. 3 zeigt eine Schaltungsvariante der Anordnung nach Fig. 1, bei der der Kondensator C2 seine Ladung über eine Anzapfung 19 der Sekundärwicklung 10 bezieht. Über die Anzapfung 19 erzeugt der Steuerimpuls S1 infolge des günstigeren Übersetzungsverhältnisses des Übertragers Ü in der Primärwicklung 9 eine größere Impulsamplitude, so daß der Steuerimpuls S1 leichter detektiert werden kann.FIG. 3 shows a circuit variant of the arrangement according to FIG. 1, in which the capacitor C2 draws its charge via a tap 19 of the secondary winding 10. Via the tap 19, the control pulse S1 generates a larger pulse amplitude as a result of the more favorable transmission ratio of the transformer U in the primary winding 9, so that the control pulse S1 can be detected more easily.

Claims (2)

Anordnung zur potentialgetrennten Übertragung von Meß- und Steuersignalen zwischen einem Meßumformer und einer Auswerteschaltung über einen magnetischen Übertrager, - bei der in einer Richtung Meßsignale vom Meßumformer zur Auswerteschaltung und in der anderen Richtung die für den Betrieb des Meßumformers erforderliche Versorgungsspannung übertragen werden, - mit einem Pulsmodulator als Meßumformer zur Erzeugung von Spannungsimpulsen, deren Pulsdauer von der Amplitude der Gleichspannung abhängt und - bei der die in der Sekundärwicklung des Übertragers induzierten Ladestrompulse eine erste Ladeschaltung mit einer Diode und einem Kondensator speisen, dessen Ladespannung als Speisespannung für den Pulsmodulator dient gekennzeichnet durch die folgenden Merkmale - ein Impulsgeber (I) erzeugt in zeitlichen Abständen (T) und mit einer vorgegebenen Zeitdauer (t) Ladestrompulse (P), die der Primärwicklung (9) des Übertragers (Ü) zugeführt werden, - die in der Sekundärwicklung (10) des Übertragers (Ü) induzierten Ladestrompulse (P) speisen die erste Ladeschaltung mit dem Gleichrichter (D1) und dem Kondensator (C1) sowie eine zweite Ladeschaltung mit einem Gleichrichter (D2) und einem Kondensator (C2), - in Reihe mit dem zweiten Kondensator (C2) liegt ein Schalter (12), der bei Betätigung den zweiten Kondensator (C2) über die Sekundärwicklung (10) entlädt und in der Primärwicklung ein Steuersignal (S1) induziert, - eine Leitung (13) verbindet die Sekundärwicklung (10) mit dem Triggereingang (E2) des Pulsmodulators (PDM), der auf Meßbetrieb schaltet und an seinem Signalausgang (A2) einen Meßimpuls (S2) liefert, sobald ein erster Puls (P1) der Ladestrompulse (P) am Triggereingang (E2) ansteht - der Meßimpuls (S2) gelangt über eine Leitung (14) an den Schalteingang des Schalters (12) und löst am Ende der Meßzeit (TM) das Steuersignal (S1) in der Primärwicklung (9) aus, - die Auswerteschaltung (15) enthält eine Zeitschaltung (Timer), die die Zeitdauer (t) der Ladestrompulse entsprechend der Beziehung t < TM < T festlegt sowie einen Triggereingang (E1), der über eine Leitung (17) mit der Primärwicklung (9) verbunden ist zur Aufnahme des Steuersignales (S1) und - die Auswerteschaltung (15) ermittelt die Zeit (Timer), die vergeht zwischen dem ersten Puls (P1) der Ladestrompulse (P) und dem Eintreffen des Steuersignales (S1) am Triggereingang (E1), die der Meßzeit (TM) entspricht und ein Maß für die Amplitude der Gleichspannung (UM) ist. Arrangement for the isolated transmission of measurement and control signals between a transmitter and an evaluation circuit via a magnetic transmitter, in which measurement signals are transmitted from the transmitter to the evaluation circuit in one direction and the supply voltage required for the operation of the transmitter is transmitted in the other direction, - With a pulse modulator as a transmitter for generating voltage pulses, the pulse duration of which depends on the amplitude of the DC voltage and - In which the charging current pulses induced in the secondary winding of the transformer feed a first charging circuit with a diode and a capacitor, the charging voltage of which serves as a supply voltage for the pulse modulator characterized by the following features - A pulse generator (I) generates charging current pulses (P) at time intervals (T) and with a predetermined duration (t), which are fed to the primary winding (9) of the transformer (Ü), - The charging current pulses (P) induced in the secondary winding (10) of the transformer (Ü) feed the first charging circuit with the rectifier (D1) and the capacitor (C1) and a second charging circuit with a rectifier (D2) and a capacitor (C2) , - In series with the second capacitor (C2) is a switch (12) which, when actuated, discharges the second capacitor (C2) via the secondary winding (10) and induces a control signal (S1) in the primary winding, - A line (13) connects the secondary winding (10) with the trigger input (E2) of the pulse modulator (PDM), which switches to measuring mode and delivers a measuring pulse (S2) at its signal output (A2) as soon as a first pulse (P1) Charge current pulses (P) are present at the trigger input (E2) - The measuring pulse (S2) reaches the switching input of the switch (12) via a line (14) and triggers the control signal (S1) in the primary winding (9) at the end of the measuring time (T M ), - The evaluation circuit (15) contains a time circuit (timer) which determines the time duration (t) of the charging current pulses according to the relationship t <T M <T and a trigger input (E1) which is connected via a line (17) to the primary winding (9 ) is connected to receive the control signal (S1) and - The evaluation circuit (15) determines the time (timer) that passes between the first pulse (P1) of the charging current pulses (P) and the arrival of the control signal (S1) at the trigger input (E1), which corresponds to the measuring time (T M ) and is a measure of the amplitude of the DC voltage (U M ). Anordnung nach Anspruch 1, dadurch gekennzeichnet, daß der Kondensator (C2) der zweiten Ladeschaltung an einer Anzapfung (19) der Sekundärwicklung (10) des Übertragers (Ü) angeschlossen ist.Arrangement according to claim 1, characterized in that the capacitor (C2) of the second charging circuit is connected to a tap (19) of the secondary winding (10) of the transformer (Ü).
EP92115976A 1991-10-25 1992-09-18 Arrangement for galvanically isolated transmission of measuring and control signals Withdrawn EP0538624A1 (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996038829A1 (en) * 1995-06-02 1996-12-05 Siemens Aktiengesellschaft Arrangement for the galvanically isolated transmission of auxiliary power (direct voltage) and information to an electronic unit
WO1998008058A1 (en) * 1996-08-23 1998-02-26 Siemens Aktiengesellschaft Circuit for intrinsically safe detection of the binary signals of a transmitter
DE10258965A1 (en) * 2002-12-16 2004-07-15 Endress + Hauser Gmbh + Co. Kg Device for optimizing the power balance of a sensor for determining and / or monitoring a physical process variable of a medium
EP2717449A1 (en) * 2012-10-05 2014-04-09 Nxp B.V. Isolated switched-mode power supply

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19640829A1 (en) * 1996-10-02 1998-03-12 Siemens Ag Circuit arrangement with isolating amplifier and measurement sensor

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1987004123A1 (en) * 1986-01-08 1987-07-16 Robert Bosch Gmbh Circuit for transmitting values measured at vehicle wheels
DE3726837A1 (en) * 1986-09-03 1988-03-17 Weinert E Messgeraetewerk Arrangement for bidirectional isolated transmission of information signals

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2733875C2 (en) * 1977-07-27 1986-04-10 Siemens AG, 1000 Berlin und 8000 München Method for digital information transmission and arrangement for carrying out the method
DE2949075C2 (en) * 1979-12-06 1982-10-28 Honeywell Gmbh, 6050 Offenbach Arrangement for contactless temperature measurement on a rotating machine part

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1987004123A1 (en) * 1986-01-08 1987-07-16 Robert Bosch Gmbh Circuit for transmitting values measured at vehicle wheels
DE3726837A1 (en) * 1986-09-03 1988-03-17 Weinert E Messgeraetewerk Arrangement for bidirectional isolated transmission of information signals

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5949659A (en) * 1995-05-02 1999-09-07 Siemens Ag Galvanically isolated transmission of power and information to an electronic unit
WO1996038829A1 (en) * 1995-06-02 1996-12-05 Siemens Aktiengesellschaft Arrangement for the galvanically isolated transmission of auxiliary power (direct voltage) and information to an electronic unit
DE19520940A1 (en) * 1995-06-02 1996-12-12 Siemens Ag Arrangement for the galvanically isolated transmission of auxiliary energy (DC voltage) and information to an electronic unit
WO1998008058A1 (en) * 1996-08-23 1998-02-26 Siemens Aktiengesellschaft Circuit for intrinsically safe detection of the binary signals of a transmitter
DE10258965A1 (en) * 2002-12-16 2004-07-15 Endress + Hauser Gmbh + Co. Kg Device for optimizing the power balance of a sensor for determining and / or monitoring a physical process variable of a medium
DE10258965B4 (en) * 2002-12-16 2007-06-21 Endress + Hauser Gmbh + Co. Kg Device for optimizing the power balance of a sensor for the determination and / or monitoring of a physical process variable of a medium
EP2717449A1 (en) * 2012-10-05 2014-04-09 Nxp B.V. Isolated switched-mode power supply
CN103715901A (en) * 2012-10-05 2014-04-09 Nxp股份有限公司 Switched-mode power supply
US8749994B2 (en) 2012-10-05 2014-06-10 Nxp B.V. Switched-mode power supply
CN103715901B (en) * 2012-10-05 2016-02-10 Nxp股份有限公司 Switching power supply

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