WO1991009276A1 - Anordnung zur verarbeitung von sensorsignalen - Google Patents
Anordnung zur verarbeitung von sensorsignalen Download PDFInfo
- Publication number
- WO1991009276A1 WO1991009276A1 PCT/EP1990/002061 EP9002061W WO9109276A1 WO 1991009276 A1 WO1991009276 A1 WO 1991009276A1 EP 9002061 W EP9002061 W EP 9002061W WO 9109276 A1 WO9109276 A1 WO 9109276A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- signal
- charge
- voltage
- switch
- feedback
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D3/00—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups
- G01D3/02—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups with provision for altering or correcting the law of variation
Definitions
- the invention consists in an arrangement for processing sensor signals, which are supplied by a resistance sensor, which when supplied with a supply signal as
- Integration result provides corresponding analog output signal, and with influencing the supply of the
- Resistance sensor by feedback of a feedback signal which is in a fixed relationship to the analog output signal in order to achieve the charge balance.
- Resistance sensor a half bridge with opposite directions
- variable resistances The are from
- Measurement charge packages displays the measurement value.
- the measurement result is therefore available in digital form, which is why they deliver Signal processing circuits of the known arrangements
- the object of the invention is to create a
- the measurement charge packages remains constant, that is
- Fig. 1 shows a schematic diagram for explaining the
- Fig. 2 shows a schematic representation of a
- Resistance sensor with measuring strips in unloaded condition shows the resistance sensor of FIG. 2 in the loaded state
- Fig. 4 shows the circuit diagram of a with guaranteed
- Fig. 5 shows timing diagrams in the
- Fig. 6 shows a schematic representation of a modified
- Embodiment of the signal processing circuits of Fig. 4 for supplying an analog output current Embodiment of the signal processing circuits of Fig. 4 for supplying an analog output current.
- Fig. 1 shows a resistance sensor 1 with which a physical quantity G, e.g. a force to be measured and a signal processing circuit 2 connected to the resistance sensor 1.
- the resistance of the sensor 1 is its electrical parameter, which is variable as a function of the physical quantity to be measured.
- a supply signal source 3 supplies the resistance sensor 1 with a supply signal V, which makes it possible to convert the change in the electrical parameter into an electrical sensor signal, which is fed to the signal processing circuit 2 and which expresses the measurement effect M, which relates the relationship between the physical quantities G and represents the electrical parameter.
- the signal processing circuit 2 converts the sensor signal into an output signal S one
- the output signal S can be, for example, an analog signal, a digital signal or a frequency.
- the force sensor 20 has an elastic carrier 21 which is clamped firmly at one end and can be deformed by a force F acting on its free end.
- Two strain gauges 22 and 23 are fastened on two opposite sides of the carrier 21 in such a way that they deform when the carrier 21 is deformed
- the ohmic resistance of strain gauges depends on the change in length.
- the two strain gauges 22 and 23 have the same ohmic resistance R.
- the strain gauge 22 has the ohmic resistance R + dR and the strain gauge 23 has the ohmic resistance R-dR .
- the force sensor 20 according to the
- Resistance sensor in which the electrical parameter, which depends on the physical size to be measured, is a resistance.
- the measuring effect M which is used to measure the force F, is preferably the resistance ratio dR / R. To obtain a sensor signal proportional to this resistance ratio, the two can be deformed in opposite directions
- FIG. 4 shows an embodiment of the
- FIG. 5 shows the time course of the associated switch control signals and voltages.
- the resistance half-bridge 60 contains two resistors 61, 62 which are connected in series between a terminal 40 and a reference conductor 41 and whose connection point forms a tap 63.
- R - dR and resistor 62 has the value R + dR.
- the resistance half-bridge 60 can thus be formed, for example, by the force sensor 20 according to FIGS. 2 and 3, the resistors 61, 62 representing the resistance values of the strain gauges 23 and 22, respectively.
- R is the resistance value of the
- the resistance ratio dR / R represents the measuring effect M of interest, which in the case of the
- the senor 60 in FIG. 4 is between two circuit blocks of the
- Signal processing circuit works on the principle of charge balance with switch-capacitor combinations. While however, such signal processing circuits usually convert the analog sensor signal into a digital output signal that represents the measured value
- the signal processing circuit of FIG. 4 is designed in a special way so that it delivers an analog output signal.
- the sensor 60 is connected on the one hand to a function block 70 and on the other hand to an intermediate storage 45.
- Function block 70 contains a switch group 71, one
- Resistor half-bridge 60 continuously connects to the non-inverting input of an operational amplifier A 1 in the buffer 45.
- the switch group 71 contains three switches S 10 , S 11 and S 12 .
- One electrode of the capacitor 72 is permanently connected to the inverting input of the operational amplifier A 1 .
- the other electrode of the capacitor 72 is connected by the switch S 10 to the terminal 40, by the switch S 11 to the reference conductor 41 and by the switch S 12 to the
- the resistance half-bridge 60 forms a voltage divider, on which, when switch S 8 is closed, a supply voltage U 1 and when switch S 9 is closed, the output voltage U A
- the voltage existing between the terminal 40 and the tap 63 at the resistor 61 is U 2 and
- Resistance 62 existing voltage is designated U 3 .
- the latch 45 contains the operational amplifier A 1 , a storage capacitor 46 of the capacitance C S and two
- Switches S 1 and S 2 When switch S 1 is closed, it connects the output of operational amplifier A 1 to its inverting input. When switch S 2 is closed, it connects the output of operational amplifier A 1 to one electrode of the storage capacitor 46, the other electrode with the inverting input of the
- Operational amplifier A 1 is connected, so that then
- Operational amplifier A 1 As already mentioned, the non-inverting input of operational amplifier A 1 is at tap 63. The potential at the inverting input
- An integrator 47 is connected downstream of the buffer store 45. This contains an operational amplifier A 2 , an integration capacitor 48 of capacitance C i in its feedback circuit and a switch S 7 . When closed, it connects the inverting input of the
- Operational amplifier A 2 is connected to a fixed potential which differs from the potential of the reference conductor 41 by a voltage U B.
- the potential at the inverting input of the operational amplifier A 2 differs by that
- Operational amplifier A 2 is connected to the output terminal 49 of the signal processing circuit. Between the
- a switch S 8 when closed, connects the
- Reference conductor 41 is the in operation of the circuit Supply voltage U 1 applied, which corresponds to the supply signal V of FIG. 1.
- the switches S 1 , S 2 and S 7 to S 12 are actuated by control signals which are supplied by a control circuit 51 which is synchronized by a clock signal generated by a clock generator 52.
- the control signals are denoted by the same reference symbols S 1 , S 2 , S 7 ... S 12 as the switches which they control.
- the timing of the control signals is shown in the diagrams in FIG. 5.
- Each switch S 1 , S 2 ... is open when the signal controlling it has a low signal value and is closed when the signal controlling it has a high signal value.
- the switches S 1 , S 2 ... are symbolic as mechanical
- FIG. 5 shows, in addition to the already mentioned time profile of the control signals S 1 ... S 12 , the time profile of the voltage U Cs across the storage capacitor 46 and of the output voltage U A over the course of several
- Each cycle Z is divided into six phases, which are numbered 1 to 6.
- the switches S 1 , S 2 are replaced by a periodic
- Switch S 1 Square wave signal controlled in push-pull so that switch S 1 is open when switch S 2 is closed, and vice versa.
- the switches S 1 , S 2 assume their alternating states for the duration of one of the phases 1 to 6. If the
- Switch S 1 is closed and switch S 2 is open, which in phases 1, 3 and 5 of each cycle Z, the one in the input circuit of operational amplifier A 1
- Storage capacitor 46 is affected.
- the circuit is then in a conditioning phase for the conditioning of the capacitor 72.
- the buffer 45 is for the transfer of charge from the capacitor 72 to the
- the switches S 8 , S 9 are also periodic
- Switch S 8 is open when switch S 9 is closed, and vice versa. During phases 1 to 4 of each cycle Z, switch S 8 is closed and switch S 9 is open.
- Phases 1 to 4 of each cycle Z thus form one
- Resistor half-bridge 60 lies. In contrast, in phases 5 and 6, switch S 9 is closed and switch S 8 is open.
- Phases 5 and 6 thus form a partial cycle Z A , in which voltage U A is applied to resistance half-bridge 60.
- Resistor half-bridge 60 has been laid
- Function block 70 provides discrete ones
- Charge packets that are transferred to the storage capacitor 46 are generated in that the capacitor 72 is switched on and off alternately by the different voltages U 2 , U 3 , U 01 by means of the switches S 10 , S 11 , S 12
- phase 1 of each cycle Z the charge applied in the previous cycle is still on the storage capacitor 46.
- Switch S 1 is closed and switch S 2 is open, so that the storage capacitor 46 from the output of the
- Operational amplifier A. is separated.
- the switch S 7 is closed for the duration of phase 1, so that a
- Integration capacitor 48 flows.
- the circuit is in the conditioning phase for the capacitor 72 for the duration of phase 1, since the
- Switch S 1 is closed and switch S 2 is open. Since the switch S 11 is also closed, the
- Capacitor 72 connected to the reference conductor 41 so that on the charge
- phase 2 of each cycle Z the switch S 1 is open and the switch S 2 is closed, so that the temporary store 45 is ready to take charge on the storage capacitor 46.
- Connection conductor 73 is connected to the non-inverting input of the operational amplifier A 1 and through the
- Phase 2 caused a negative voltage change because the voltage U 2 (1-4) is less than the voltage U 2 (1- 4) .
- Phase 5 is again a conditioning phase for the
- Capacitor 72 Since switch S 10 is closed, capacitor 72 is on charge
- phase 6 the switch S 1 1 is closed, so that the capacitor 72 is connected to the reference conductor 41 and to the charge
- the transhipment quantity is as
- the compensation charge packet dQ K causes one to do so
- Each cycle Z can consist of n sub-cycles Z 1 and k sub-cycles Z A ;
- Discharge storage capacitor 46 to the residual charge Q Cs (R) .
- the circuit therefore works as a control loop, which tries to bring the output voltage U A to a value at which the sum of the k
- Measurement charge packets dQ M is. When this state is reached, there is a charge balance in the storage capacitor 46:
- the capacitance value of the capacitor 72 does not go into the
- Capacitors 46 and 48 the offset voltages of the
- the value of the voltage U 1 is only limited by the working range of the circuit. If one chooses the supply voltage U 1
- Power supply voltage is proportional.
- FIG. 6 shows a modification of the circuit of FIG. 4, which supplies an analog output current I A instead of an analog output voltage U A. 6 are the Buffer 45 and the integrator 47 of FIG. 4 represented by a circuit block 80, which from the
- Resistor half-bridge 60 and consists of the function block 70 of FIG. 4.
- the output of the integrator 47 is connected in FIG. 6 to the base of an NPN transistor 81, which serves as an emitter follower with a resistor 82 of the value R A located in the emitter circuit.
- the feedback leading to switch S 9 is connected to the emitter of transistor 81 which
- Output voltage U A of the integrator 47 can be
- I A / U 1 [n / (kR A )] ⁇ (dR / R) (24) 6 is particularly suitable for
- Measuring arrangements in which the measured value signal is transmitted in the form of a direct current via a single two-wire line, which can vary, for example, between 4 mA and 20 mA and in which the supply current for the sensor and the
Landscapes
- Engineering & Computer Science (AREA)
- Technology Law (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
- Arrangements For Transmission Of Measured Signals (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
- Measurement Of Force In General (AREA)
- Indication And Recording Devices For Special Purposes And Tariff Metering Devices (AREA)
- Amplifiers (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3500125A JPH073340B2 (ja) | 1989-12-07 | 1990-11-30 | センサ信号を処理する装置 |
CA002046269A CA2046269C (en) | 1989-12-07 | 1990-11-30 | Arrangement for processing sensor signals |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEP3940537.0 | 1989-12-07 | ||
DE3940537A DE3940537A1 (de) | 1989-12-07 | 1989-12-07 | Anordnung zur verarbeitung von sensorsignalen |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1991009276A1 true WO1991009276A1 (de) | 1991-06-27 |
Family
ID=6395039
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP1990/002061 WO1991009276A1 (de) | 1989-12-07 | 1990-11-30 | Anordnung zur verarbeitung von sensorsignalen |
Country Status (9)
Country | Link |
---|---|
US (1) | US5210501A (de) |
EP (1) | EP0457868B1 (de) |
JP (1) | JPH073340B2 (de) |
CA (1) | CA2046269C (de) |
DE (2) | DE3940537A1 (de) |
DK (1) | DK0457868T3 (de) |
ES (1) | ES2045957T3 (de) |
IE (1) | IE904150A1 (de) |
WO (1) | WO1991009276A1 (de) |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5451940A (en) * | 1989-12-20 | 1995-09-19 | Endress U. Hauser Gmbh U. Co. | Capacitive sensor signal processing arrangement using switch capacitor structures |
US5541531A (en) * | 1995-05-01 | 1996-07-30 | Ford Motor Company | Switch capacitor interface circuit |
EP0780674B1 (de) * | 1995-12-22 | 1999-11-03 | ENVEC Mess- und Regeltechnik GmbH + Co. | Druckmessanordnung mit Schirmelektrode |
DE19744152A1 (de) * | 1997-10-07 | 1999-04-29 | Ifm Electronic Gmbh | Schaltungsanordnung zur Erfassung der Kapazität bzw. einer Kapazitätsänderung eines kapazitiven Schaltungs- oder Bauelementes |
EP0797084B1 (de) | 1996-03-23 | 2001-01-17 | Endress + Hauser GmbH + Co. | Verfahren zum Herstellen von kapazitiven, in Nullpunkt-Langzeit-Fehlerklassen sortierten Keramik-Absolutdruck-Sensoren |
DE10105982A1 (de) * | 2001-02-09 | 2002-10-02 | Siemens Ag | Verfahren zur Auswertung eines Messwertes und zugehörige Schaltungsanordnung |
US20020190733A1 (en) * | 2001-06-11 | 2002-12-19 | Dainichiro Kinoshita | Circuit for detecting a minute change in resistance |
FR2860867B1 (fr) * | 2003-10-09 | 2006-02-03 | Electricfil Automotive | Disposituf pour corriger les erreurs d'interferences entre des capteurs magnetiques de mesure de la position de mobiles |
KR101525209B1 (ko) * | 2008-11-04 | 2015-06-05 | 삼성전자주식회사 | 모듈 테스트 장치 및 그것을 포함하는 테스트 시스템 |
US8854062B2 (en) * | 2011-08-29 | 2014-10-07 | Robert Bosch Gmbh | Readout circuit for self-balancing capacitor bridge |
DE102012200191A1 (de) * | 2012-01-09 | 2013-07-11 | Ifm Electronic Gmbh | Kapazitiver Drucksensor |
RU209242U1 (ru) * | 2020-09-24 | 2022-02-08 | Акционерное общество "ПКК МИЛАНДР" | Многофункциональный многотарифный счетчик со сменными унифицированными модулями |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0007288A1 (de) * | 1978-07-14 | 1980-01-23 | Terraillon | Vorrichtung zum Messen der Intensität einer Kraft, transversal angewandt am freien Ende eines einseitig eingeklemmten Biegungsbalkens |
EP0105120A2 (de) * | 1982-09-30 | 1984-04-11 | International Business Machines Corporation | Verfahren und Gerät zum Messen der Signale von Differentialgebern |
EP0216288A1 (de) * | 1985-09-17 | 1987-04-01 | MARELLI AUTRONICA S.p.A. | Zwischenschaltung zwischen einem Wandler, insbesondere einem Dickschichtwiderstand-Druckwandler und einem elektrodynamischen Instrument und mit einer solchen Schaltung ausgerüsteter Wandler |
DE3633791C2 (de) * | 1986-10-03 | 1989-12-21 | Endress U. Hauser Gmbh U. Co, 7864 Maulburg, De |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CH665027A5 (de) * | 1984-09-06 | 1988-04-15 | Mettler Instrumente Ag | Verfahren zur messung und digitalisierung eines widerstandes und schaltung zur durchfuehrung des verfahrens. |
US4878012A (en) * | 1988-06-10 | 1989-10-31 | Rosemount Inc. | Charge balanced feedback transmitter |
-
1989
- 1989-12-07 DE DE3940537A patent/DE3940537A1/de not_active Withdrawn
-
1990
- 1990-11-16 IE IE415090A patent/IE904150A1/en unknown
- 1990-11-21 US US07/616,339 patent/US5210501A/en not_active Expired - Fee Related
- 1990-11-30 DE DE90917588T patent/DE59003256D1/de not_active Expired - Fee Related
- 1990-11-30 CA CA002046269A patent/CA2046269C/en not_active Expired - Fee Related
- 1990-11-30 DK DK90917588.7T patent/DK0457868T3/da active
- 1990-11-30 ES ES90917588T patent/ES2045957T3/es not_active Expired - Lifetime
- 1990-11-30 WO PCT/EP1990/002061 patent/WO1991009276A1/de active IP Right Grant
- 1990-11-30 EP EP90917588A patent/EP0457868B1/de not_active Expired - Lifetime
- 1990-11-30 JP JP3500125A patent/JPH073340B2/ja not_active Expired - Lifetime
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0007288A1 (de) * | 1978-07-14 | 1980-01-23 | Terraillon | Vorrichtung zum Messen der Intensität einer Kraft, transversal angewandt am freien Ende eines einseitig eingeklemmten Biegungsbalkens |
EP0105120A2 (de) * | 1982-09-30 | 1984-04-11 | International Business Machines Corporation | Verfahren und Gerät zum Messen der Signale von Differentialgebern |
EP0216288A1 (de) * | 1985-09-17 | 1987-04-01 | MARELLI AUTRONICA S.p.A. | Zwischenschaltung zwischen einem Wandler, insbesondere einem Dickschichtwiderstand-Druckwandler und einem elektrodynamischen Instrument und mit einer solchen Schaltung ausgerüsteter Wandler |
DE3633791C2 (de) * | 1986-10-03 | 1989-12-21 | Endress U. Hauser Gmbh U. Co, 7864 Maulburg, De |
Also Published As
Publication number | Publication date |
---|---|
DK0457868T3 (da) | 1993-12-27 |
DE3940537A1 (de) | 1991-06-13 |
JPH073340B2 (ja) | 1995-01-18 |
DE59003256D1 (de) | 1993-12-02 |
CA2046269C (en) | 1999-12-21 |
IE904150A1 (en) | 1991-06-19 |
EP0457868A1 (de) | 1991-11-27 |
EP0457868B1 (de) | 1993-10-27 |
JPH04500413A (ja) | 1992-01-23 |
ES2045957T3 (es) | 1994-01-16 |
CA2046269A1 (en) | 1991-06-08 |
US5210501A (en) | 1993-05-11 |
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