EP0817149B1 - Circuit for transmitting a measurement current from an intrinsically safe sensor to a non-intrinsical area - Google Patents

Circuit for transmitting a measurement current from an intrinsically safe sensor to a non-intrinsical area Download PDF

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Publication number
EP0817149B1
EP0817149B1 EP97109825A EP97109825A EP0817149B1 EP 0817149 B1 EP0817149 B1 EP 0817149B1 EP 97109825 A EP97109825 A EP 97109825A EP 97109825 A EP97109825 A EP 97109825A EP 0817149 B1 EP0817149 B1 EP 0817149B1
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EP
European Patent Office
Prior art keywords
intrinsically safe
current
circuit
safe area
transformer
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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 - Lifetime
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EP97109825A
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German (de)
French (fr)
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EP0817149A1 (en
Inventor
Robert Dipl.Ing. Ahr (Fh)
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Endress and Hauser Wetzer GmbH and Co KG
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Endress and Hauser Wetzer GmbH and Co KG
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    • G—PHYSICS
    • G08—SIGNALLING
    • G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
    • G08C19/00—Electric signal transmission systems
    • G08C19/02—Electric signal transmission systems in which the signal transmitted is magnitude of current or voltage

Definitions

  • the invention relates to a circuit arrangement for Transmission of a measuring current from an intrinsically safe Sensor arrangement in a non-intrinsically safe area by means of a current measuring resistor located therein.
  • sensors electrical signals that the sensors due to a generate physical or chemical law, in a measuring current corresponding to the measuring range of a sensor formed from 4 mA to 20 mA.
  • the sensor is through one provided for this purpose and structurally combined with the sensor Forming stage expands and forms a sensor arrangement.
  • DE-A 35 26 997 is a circuit arrangement described for the transmission of a in a first Circuit generated measuring current from 0 mA to 20 mA in one second circuit by means of a transformer, which to one of the energy supply of the first circuit used and lying on its side DC converter belongs, with the transformer on the side of the second circuit two in series has switched partial windings on the Connection point a first pole of an energy source and on their connections facing away from the connection point second pole of the energy source.
  • DE-A 38 12 861 Circuit arrangement for the intrinsically safe power supply of a non-intrinsically safe area using an in DC converter located in this area to which a push-pull transformer belongs the one facing the non-intrinsically safe area Primary winding with two of the same, in opposite directions in series switched partial windings and one intrinsically safe Area facing secondary winding with two identical, has partial windings connected in opposite directions in series.
  • FIG. 1 In the block diagram of the figure is a circuit arrangement for transmitting one from a sensor arrangement 1 with a Sensor 11 emitted measuring current I via a transformer 2 shown.
  • the conditions for an intrinsically safe Range are e.g. in the European standards EN 50014 to EN 50039 defined.
  • the offset setting level 6 receives a corresponding one Setting signal 61 supplied and mainly serves Correction or compensation of idle losses of the Transformer 2, the current measuring resistor 5 as Idle current along with one from the secondary side of the Transformer 2 ago transmitted, the measuring current I flow through proportional current. So this is the most Measuring resistor 5 falling voltage not proportional to Measuring current I.
  • the offset setting stage 6 is preferred realized by means of an operational amplifier, the Degree of gain adjustable by means of a potentiometer is made.
  • the secondary side of the transformer 2 feeds one Rectifier and smoothing stage 8 and this in turn an intrinsic safety conditioning level 9.
  • an intrinsic safety conditioning level 9 contains those components that correspond to the mentioned standards the prescribed voltage and Allow maximum current values to be observed. These components are in particular longitudinal resistances in each of the feed lines Sensor arrangement 1 and connected in parallel to this Protective diodes, e.g. Zener diodes.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Arrangements For Transmission Of Measured Signals (AREA)
  • Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)

Abstract

The sensor Ä1Ü is located in an intrinsically safe region Ä10Ü and is connected with a current measuring resistor in a non-intrinsically safe region Ä20Ü. The sensor output is in the 4-20 mA range, and is supplied from the secondary of a transformer Ä2Ü via a rectifier unit Ä8Ü and a conditioning stage Ä9Ü. The transformer has a primary with two windings Ä21,22Ü which are coupled to an output stage arrangement Ä31Ü, in which the current measuring resistor connected to the centre tap of the transformer primary. The voltage developed across the resistor is fed to an offset unit, and subsequently to a voltage to current converter (7),

Description

Die Erfindung betrifft eine Schaltungsanordnung zur Übertragung eines Meßstroms von einer eigensicheren Sensoranordnung in einen nicht-eigensicheren Bereich mittels eines in diesem liegenden Strom-Meßwiderstands.The invention relates to a circuit arrangement for Transmission of a measuring current from an intrinsically safe Sensor arrangement in a non-intrinsically safe area by means of a current measuring resistor located therein.

Nach einem seit langem bestehenden Standard der industriellen Meßtechnik werden von Sensoren abgegebene elektrische Signale, die die Sensoren aufgrund einer physikalischen oder chemischen Gesetzmäßigkeit erzeugen, in einen dem Meßbereich eines Sensors entsprechenden Meßstrom von 4 mA bis 20 mA umgeformt. Oft ist der Sensor durch eine hierfür vorgesehene und mit dem Sensor baulich vereinigte Umformstufe erweitert und bildet eine Sensoranordnung.According to a longstanding standard of industrial measuring technology are emitted by sensors electrical signals that the sensors due to a generate physical or chemical law, in a measuring current corresponding to the measuring range of a sensor formed from 4 mA to 20 mA. Often the sensor is through one provided for this purpose and structurally combined with the sensor Forming stage expands and forms a sensor arrangement.

Der Meßstrom kann einerseits über eine Übertragungsleitung, z.B über eine Zweidrahtleitung, zu einem geeigneten Anzeigeort, z.B. zu einer Meßzentrale, geleitet werden. Über die Übertragungsleitung erfolgt andererseits die Energieversorgung der Sensoranordnung.The measuring current can on the one hand via a transmission line, e.g. via a two-wire line to a suitable one Display location, e.g. to a measuring center. On the other hand, via the transmission line Power supply to the sensor arrangement.

In letzterem Zusammenhang ist in der DE-A 27 01 184 eine Schaltungsanordnung beschrieben, die zur Übertragung eines von einer Sensoranordnung an einer Meßstelle abgegebenen Meßstroms zu einem davon entfernt liegenden Strom-Meßwiderstand bei gleichzeitiger Energieversorgung der Sensoranordnung über den in Serie zu einer Energiequelle liegenden Strom-Meßwiderstand mittels einer Zweidrahtleitung dient.In the latter context, DE-A 27 01 184 is a Circuit arrangement described for the transmission of a emitted by a sensor arrangement at a measuring point Measuring current to a current measuring resistor located away from it with simultaneous power supply to the Sensor arrangement via the in series to an energy source lying current measuring resistor by means of a Two-wire line is used.

Ferner ist in der DE-A 35 26 997 eine Schaltungsanordnung beschrieben, die zur Übertragung eines in einem ersten Stromkreis erzeugten Meßstroms von 0 mA bis 20 mA in einen zweiten Stromkreis mittels eines Transformators dient, der zu einem der Energieversorgung des ersten Stromkreises benutzten und auf dessen Seite liegenden Gleichspannungswandler gehört, wobei der Transformator auf der Seite des zweiten Stromkreises zwei in Serie geschaltete Teilwicklungen aufweist, an deren Verbindungspunkt ein erster Pol einer Energiequelle und an deren vom Verbindungspunkt abgewandten Anschlüssen ein zweiter Pol der Energiequelle liegt.Furthermore, in DE-A 35 26 997 is a circuit arrangement described for the transmission of a in a first Circuit generated measuring current from 0 mA to 20 mA in one second circuit by means of a transformer, which to one of the energy supply of the first circuit used and lying on its side DC converter belongs, with the transformer on the side of the second circuit two in series has switched partial windings on the Connection point a first pole of an energy source and on their connections facing away from the connection point second pole of the energy source.

Schließlich ist in der DE-A 38 12 861 eine Schaltungsanordnung zur eigensicheren Energieversorgung von einem nicht-eigensicheren Bereich aus mittels eines in diesem Bereich liegenden Gleichspannungswandlers beschrieben, zu dem ein Gegentakt-Transformator gehört, der eine dem nicht-eigensicheren Bereich zugewandte Primärwicklung mit zwei gleichen, gegensinnig in Serie geschalteten Teilwicklungen und eine dem eigensicheren Bereich zugewandte Sekundärwicklung mit zwei gleichen, gegensinnig in Serie geschalteten Teilwicklungen aufweist.Finally, in DE-A 38 12 861 Circuit arrangement for the intrinsically safe power supply of a non-intrinsically safe area using an in DC converter located in this area to which a push-pull transformer belongs, the one facing the non-intrinsically safe area Primary winding with two of the same, in opposite directions in series switched partial windings and one intrinsically safe Area facing secondary winding with two identical, has partial windings connected in opposite directions in series.

Eine Aufgabe der Erfindung besteht darin, eine Schaltungsanordnung zur Übertragung eines von einer Sensoranordnung an einer in einem eigensicheren Bereich liegenden Meßstelle abgegebenen Meßstroms zu einem nichteigensicheren Bereich mittels eines in diesem liegenden Strom-Meßwiderstands bei gleichzeitiger Energieversorgung der Sensoranordnung vom nicht-eigensicheren Bereich aus mittels eines Gleichspannungswandlers zu schaffen. An object of the invention is a Circuit arrangement for the transmission of one of a Sensor arrangement on one in an intrinsically safe area the measuring current supplied to a non-intrinsically safe Area by means of a lying in it Current measuring resistor with simultaneous power supply the sensor arrangement from the non-intrinsically safe area by means of a DC converter.

Zur Lösung dieser Aufgabe besteht die Erfindung in einer Schaltungsanordnung zur Übertragung eines von einer Sensoranordnung an einer in einem eigensicheren Bereich liegenden Meßstelle abgegebenen Meßstroms über einen Transformator zu einem nicht-eigensicheren Bereich mittels eines in diesem liegenden Strom-Meßwiderstands bei gleichzeitiger Energieversorgung der Sensoranordnung mittels eines Gleichspannungswandlers, zu dem der Transformator gehört, der eine dem nicht-eigensicheren Bereich zugewandte Primärwicklung mit zwei gleichen, gleichsinnig in Serie geschalteten Teilwicklungen und eine einzige dem eigensicheren Bereich zugewandte Sekundärwicklung aufweist, bei welcher Schaltungsanordnung

  • ein erstes Ende des Strom-Meßwiderstands an einem Schaltungsnullpunkt und ein zweites Ende des Strom-Meßwiderstands an einem Mittenabgriff einer Ausgangsstufe des Gleichspannungswandlers liegt, die mit den Teilwicklungen der Primärwicklung verbunden ist,
  • der Mittenabgriff am Eingang einer Offset-Einstellstufe angeschlossen ist,
  • der Ausgang der Offset-Einstellstufe mit dem Eingang eines Spannungs-Strom-Wandlers verbunden ist und
  • ein erster Pol einer Energiequelle am Verbindungspunkt der Teilwicklungen und ein zweiter Pol der Energiequelle am Schaltungsnullpunkt liegt.
To achieve this object, the invention consists in a circuit arrangement for transmitting a measuring current emitted by a sensor arrangement at a measuring point located in an intrinsically safe area via a transformer to a non-intrinsically safe area by means of a current measuring resistor located therein while simultaneously supplying energy to the sensor arrangement by means of a DC voltage converter, to which the transformer belongs, which has a primary winding facing the non-intrinsically safe area with two identical partial windings connected in series in the same direction and a single secondary winding facing the intrinsically safe area, in which circuit arrangement
  • a first end of the current measuring resistor lies at a circuit zero point and a second end of the current measuring resistor lies at a center tap of an output stage of the direct voltage converter, which is connected to the partial windings of the primary winding,
  • the center tap is connected to the input of an offset setting stage,
  • the output of the offset setting stage is connected to the input of a voltage-current converter and
  • a first pole of an energy source is at the connection point of the partial windings and a second pole of the energy source is at the circuit zero point.

Ein Vorteil der Erfindung besteht darin, daß mittels der Offset-Einstellstufe die Wirkung der Leerlaufverluste auf die Proportionalität des übertragenen Meßstroms minimiert werden kann.An advantage of the invention is that by means of Offset adjustment level the effect of the no-load losses the proportionality of the transmitted measuring current is minimized can be.

Die Erfindung und weitere Vorteile werden nun anhand eines Ausführungsbeispiels, das in der Figur der Zeichnung dargestellt ist, näher erläutert. The invention and further advantages are now based on a Embodiment that in the figure of the drawing is illustrated, explained in more detail.

Im Blockschaltbild der Figur ist eine Schaltungsanordnung zur Übertragung eines von einer Sensoranordnung 1 mit einem Sensor 11 abgegebenen Meßstroms I über einen Transformator 2 gezeigt. Die Sensoranordnung 1 mit dem Sensor 11, also eine Meßstelle, liegt dabei in einem eigensicheren Bereich 10, wie durch die beiden nach links weisenden Pfeile angedeutet ist. Die Bedingungen für einen eigensicheren Bereich sind z.B. in den europäischen Normen EN 50014 bis EN 50039 definiert.In the block diagram of the figure is a circuit arrangement for transmitting one from a sensor arrangement 1 with a Sensor 11 emitted measuring current I via a transformer 2 shown. The sensor arrangement 1 with the sensor 11, that is a measuring point lies in an intrinsically safe area 10, as by the two arrows pointing to the left is indicated. The conditions for an intrinsically safe Range are e.g. in the European standards EN 50014 to EN 50039 defined.

Der Sensor 11 wandelt eine physikalische Meßgröße, wie z.B. einen Druck, eine Temperatur, einen Durchfluß, einen Füllstand, einen pH-Wert, ein Redox-Potential, eine Gaskonzentration, eine Feuchtekonzentration etc., in eine entsprechende elektrische Größe um, wie z.B. einen Strom oder eine Spannung. Die Sensoranordnung 1 erzeugt dann aus diesem Strom oder aus dieser Spannung den dazu proportionalen Meßstrom I, der den eingangs erwähnten Standard-Bereich von 4 mA bis 20 mA umfassen kann.The sensor 11 converts a physical measured variable, e.g. a pressure, a temperature, a flow rate, a Level, a pH value, a redox potential, a Gas concentration, a moisture concentration etc., in a corresponding electrical quantity, e.g. a stream or a tension. The sensor arrangement 1 then generates this current or from this voltage proportional measuring current I, the one mentioned above Standard range can range from 4 mA to 20 mA.

Der Transformator 2 liegt zusammen mit weiteren, noch zu beschreibenden Komponenten und Teilschaltungen in einem nicht-eigensicheren Bereich 20, wie durch die nach rechts weisenden Pfeile angedeutet ist. Der Transformator 2 gehört zu einem Gleichspannungswandler 3, der eine dem nichteigensicheren Bereich 20 zugewandte Primärwicklung mit zwei gleichen, gleichsinnig in Serie geschalteten Teilwicklungen 21, 22 und eine einzige dem eigensicheren Bereich 10 zugewandte Sekundärwicklung 23 aufweist.The transformer 2 is still together with others descriptive components and subcircuits in one non-intrinsically safe area 20, as through the right pointing arrows is indicated. The transformer 2 belongs to a DC-DC converter 3, the one of the non-intrinsically safe Area 20 facing primary winding with two same partial windings connected in the same direction in series 21, 22 and a single intrinsically safe area 10 facing secondary winding 23.

Der Gleichspannungswandler 3 umfaßt ferner eine Ausgangsstufe 31, die im Ausführungsbeispiel der Figur eine Gegentaktendstufe mit zwei mit ihren gesteuerten Strompfaden in Serie liegenden MOS-Leistungstransistoren ist, und eine Oszillatorstufe 32, die bevorzugt Rechteckimpulse zur Ansteuerung der Ausgangsstufe 31 erzeugt.The DC-DC converter 3 further includes one Output stage 31, the one in the embodiment of the figure Push-pull output stage with two with their controlled Current paths in series MOS power transistors and an oscillator stage 32 which is preferred Rectangular pulses to control output stage 31 generated.

Die Versorgung der Ausgangsstufe 31 erfolgt durch eine Energiequelle 4, von der ein erster Pol am Verbindungspunkt der beiden Teilwicklungen 21, 22 und ein zweiter Pol an einem Schaltungsnullpunkt SN angeschlossen ist, der zum nicht-eigensicheren Bereich 20 gehört.The output stage 31 is supplied by a Energy source 4, of which a first pole at the connection point of the two partial windings 21, 22 and a second pole a circuit zero point SN is connected to heard non-intrinsically safe area 20.

Ein erstes Ende eines Strom-Meßwiderstands 5 liegt am Schaltungsnullpunkt SN und ein zweites Ende des Strom-Meßwiderstands an einem Mittenabgriff der Ausgangsstufe 31. An diesem Mittenabgriff und somit auch am vom Schaltungsnullpunkt SN abgewandten zweiten Ende des Strom-Meßwiderstands 5 liegt der Eingang einer Offset-Einstellstufe 6. Deren Ausgang ist mit dem Eingang eines Spannungs-Strom-Wandlers 7 verbunden, an dessen Ausgang der Meßstrom I abgenommen werden kann.A first end of a current measuring resistor 5 is on Circuit zero point SN and a second end of the current measuring resistor on a center tap of output stage 31. At this center tap and thus also from Circuit zero SN facing away from the second end of the current measuring resistor 5 is the input of an offset setting stage 6. Its output is with the input one Voltage-current converter 7 connected to the output of the Measuring current I can be taken.

Die Offset-Einstellstufe 6 erhält ein entsprechendes Einstellsignal 61 zugeführt und dient hauptsächlich der Korrektur bzw. der Kompensation von Leerlaufverlusten des Transformators 2, die den Strom-Meßwiderstand 5 als Leerlaufstrom zusammen mit einem von der Sekundärseite des Transformators 2 her übertragenen, dem Meßstrom I proportionalen Strom durchfließen. Somit ist aber die am Meßwiderstand 5 abfallende Spannung nicht proportional zum Meßstrom I. Die Offset-Einstellstufe 6 ist bevorzugt mittels eines Operationsverstärkers realisiert, dessen Verstärkungsgrad mittels eines Potentiometers einstellbar gemacht ist.The offset setting level 6 receives a corresponding one Setting signal 61 supplied and mainly serves Correction or compensation of idle losses of the Transformer 2, the current measuring resistor 5 as Idle current along with one from the secondary side of the Transformer 2 ago transmitted, the measuring current I flow through proportional current. So this is the most Measuring resistor 5 falling voltage not proportional to Measuring current I. The offset setting stage 6 is preferred realized by means of an operational amplifier, the Degree of gain adjustable by means of a potentiometer is made.

Die Sekundärseite des Transformators 2 speist eine Gleichrichter- und Glättungsstufe 8 und diese ihrerseits eine Eigensicherheit-Konditionierungsstufe 9. In dieser sind diejenigen Komponenten enthalten, die entsprechend den erwähnten Normen die darin vorgeschriebenen Spannungs- und Strom-Maximalwerte einzuhalten gestatten. Diese Komponenten sind insb. Längs-Widerstände in jeder der Zuleitungen zur Sensoranordung 1 und zu diesen parallelgeschaltete Schutzdioden, z.B. Z-Dioden.The secondary side of the transformer 2 feeds one Rectifier and smoothing stage 8 and this in turn an intrinsic safety conditioning level 9. In this contain those components that correspond to the mentioned standards the prescribed voltage and Allow maximum current values to be observed. These components are in particular longitudinal resistances in each of the feed lines Sensor arrangement 1 and connected in parallel to this Protective diodes, e.g. Zener diodes.

Claims (1)

  1. A circuit arrangement for transmitting a measurement current (I), which is output by a sensor arrangement (1) at a measurement point or location situated in an intrinsically safe area (10), via a transformer (2) to a non-intrinsically safe area (20) by means of a current measuring resistor (5), which is situated in the latter, in conjunction with simultaneous power supply of the sensor arrangement by means of a DC con-verter (3), to which the transformer belongs, which has a primary winding, which faces the non-intrinsically safe area and has two identical partial windings (21, 22) connected in series in the same sense, and a single secondary winding (23), which faces the intrinsically safe area, in which circuit arrangement
    a first end of the current measuring resistor (5) is connected to a circuit zero-point (SN) and a second end of the current measuring resistor is connected to a center tap of an output stage (31) of the DC converter (3), the output stage being connected to the partial windings (21, 22) of the primary winding,
    the center tap is connected to the input of an offset adjusting stage (6),
    an output of the offset adjusting stage is connected to the input of a voltage/current converter (7), and
    a first pole of a power source (4) is connected to the junction point of the partial windings (21, 22) and a second pole of the power source is connected to the circuit zero-point.
EP97109825A 1996-06-28 1997-06-17 Circuit for transmitting a measurement current from an intrinsically safe sensor to a non-intrinsical area Expired - Lifetime EP0817149B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP97109825A EP0817149B1 (en) 1996-06-28 1997-06-17 Circuit for transmitting a measurement current from an intrinsically safe sensor to a non-intrinsical area

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
EP96110541 1996-06-28
EP96110541 1996-06-28
EP97109825A EP0817149B1 (en) 1996-06-28 1997-06-17 Circuit for transmitting a measurement current from an intrinsically safe sensor to a non-intrinsical area

Publications (2)

Publication Number Publication Date
EP0817149A1 EP0817149A1 (en) 1998-01-07
EP0817149B1 true EP0817149B1 (en) 1999-05-12

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EP97109825A Expired - Lifetime EP0817149B1 (en) 1996-06-28 1997-06-17 Circuit for transmitting a measurement current from an intrinsically safe sensor to a non-intrinsical area

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US (1) US5907292A (en)
EP (1) EP0817149B1 (en)
AT (1) ATE180085T1 (en)
CA (1) CA2209208C (en)
DE (1) DE59700161D1 (en)
DK (1) DK0817149T3 (en)
ES (1) ES2134046T3 (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6141194A (en) * 1998-09-22 2000-10-31 Simmonds Precision Products, Inc. Aircraft fuel tank protective barrier and method
CA2277686A1 (en) * 1999-07-14 2001-01-14 Milltronics Ltd. An intrinsically safe universal switching power supply
ATE451603T1 (en) * 2001-06-19 2009-12-15 Flowtec Ag VISCOSITY MEASUREMENT DEVICE
EP1296128A1 (en) * 2001-09-21 2003-03-26 Endress + Hauser Flowtec AG Viscosimeter
US6970100B2 (en) * 2001-07-05 2005-11-29 Long Range Systems, Inc. Temperature tag and system for monitoring, recording, and reporting temperature readings
DE10253603A1 (en) * 2002-11-15 2004-06-03 Endress + Hauser Conducta Gesellschaft für Mess- und Regeltechnik mbH + Co. KG Method for generating software modules for field devices in process automation technology
DE10255741A1 (en) * 2002-11-28 2004-06-09 Endress + Hauser Conducta Gesellschaft für Mess- und Regeltechnik mbH + Co. KG Modular transmitter with galvanically isolated sensor
DE102006009506B4 (en) * 2006-02-27 2010-09-23 Phoenix Contact Gmbh & Co. Kg Bidirectional, galvanically isolated transmission channel
DE102014112452B4 (en) * 2014-08-29 2022-03-31 Endress + Hauser Flowtec Ag Explosion protection circuit with impedance matching
AT516903B1 (en) * 2015-03-09 2020-10-15 Fronius Int Gmbh Circuit arrangement with transformer with center tap and measurement of the output voltage

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3764880A (en) * 1972-05-08 1973-10-09 Rosemount Inc Two-wire current transmitter with isolated transducer circuit
DE2701184A1 (en) * 1977-01-13 1978-07-27 Endress Hauser Gmbh Co CIRCUIT ARRANGEMENT FOR TRANSMISSION OF MEASURED VALUE SIGNALS
CH620537A5 (en) * 1977-03-03 1980-11-28 Bauer Messinstrumente Ag Device for reducing losses and thus for improving the transfer characteristic at a measurement-value transformer
US4532510A (en) * 1982-06-24 1985-07-30 Sereg, S.A. Measuring apparatus having a sensor located remotely from its electricity power supply
DE3526997A1 (en) * 1984-07-28 1986-02-06 Knick Elektronische Meßgeräte GmbH & Co, 1000 Berlin Direct current transmission circuit
US4725839A (en) * 1984-12-21 1988-02-16 Ferranti Subsea Systems, Ltd. Remote, inductively coupled, transducer interface
DE3812861A1 (en) * 1988-04-18 1989-10-26 Siemens Ag Intrinsically safe current supply device

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CA2209208C (en) 2000-09-12
DK0817149T3 (en) 1999-11-15
CA2209208A1 (en) 1997-12-28
DE59700161D1 (en) 1999-06-17
ATE180085T1 (en) 1999-05-15
EP0817149A1 (en) 1998-01-07
ES2134046T3 (en) 1999-09-16
US5907292A (en) 1999-05-25

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