CN1131436C - Circuit to convert capacitance, resistance and inductance into digital amount - Google Patents
Circuit to convert capacitance, resistance and inductance into digital amount Download PDFInfo
- Publication number
- CN1131436C CN1131436C CN 99119404 CN99119404A CN1131436C CN 1131436 C CN1131436 C CN 1131436C CN 99119404 CN99119404 CN 99119404 CN 99119404 A CN99119404 A CN 99119404A CN 1131436 C CN1131436 C CN 1131436C
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- resistance
- electric
- circuit
- inductance
- voltage
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/12—Circuits for multi-testers, i.e. multimeters, e.g. for measuring voltage, current, or impedance at will
- G01R15/125—Circuits for multi-testers, i.e. multimeters, e.g. for measuring voltage, current, or impedance at will for digital multimeters
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M1/00—Analogue/digital conversion; Digital/analogue conversion
- H03M1/12—Analogue/digital converters
- H03M1/50—Analogue/digital converters with intermediate conversion to time interval
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- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The present invention relates to a capacitor, resistor and inductor digital conversion circuit. Each capacitor, resistor and inductor are connected with an electric control switch controlled by a controller, and a comparator is connected with a timer connected with the controller. The electric control switch can control the capacitor to gate the resistor or the inductor to form resistance-capacitance or inductance-capacitance, and a charging and discharging loop can be used to measure resistance and capacitance or inductance and capacitance. One end of the capacitor is connected with a comparison circuit, the timer can meter charging and discharging time, and a plurality of switches connected in series can measure a sensor array. The present invention convert a testing problem of the elements to a time sequence problem. A digital circuit is used for conversion to simplify a complex circuit used in the past which converts an element value to an analog electrical value to carry out analog/digital conversion.
Description
The present invention relates to a kind of electronic circuit and relate in particular to a kind of circuit that electric capacity, resistance value, inductance value is converted to numeral, to adopt simple digital circuit to realize the capacitance resistance inductance value is converted to numeral, increase and measure passage and do not increase circuit substantially and can measure.
In scientific and technological productive life, often capacitor value, resistance value, inductance value in the electronic component need be converted to digital signal, as temperature sensor, humidity sensor, pressure transducer, position transducer etc.Conventional transform method is by translation circuit and amplifying circuit its conversion to be enlarged into magnitude of voltage, be transformed into digital quantity by mould/number circuit again, multichannel is measured simultaneously if desired, then need a plurality of transducers, amplifier and circuit-changing switch, circuit is with regard to more complicated like this, components and parts are many, and cost is also higher.
The object of the invention is to provide a kind of circuit that electric capacity, resistance value, inductance value are converted to the low complex degree of numeral and directly realize by digital circuit cheaply.The present invention is achieved in that
A kind of electric capacity, resistance, the inductance digital conversion circuit, by electric capacity, inductance, resistance, comparer, timer, controller, electric-controlled switch is formed, each electric capacity wherein, resistance all links to each other with the electric-controlled switch of controller control, controller can be formed the capacitance-resistance charging and discharging circuit by electric-controlled switch control capacitance gating resistance, but measuring resistance and electric capacity, the end that electric capacity links to each other with resistance links to each other with comparer, the reference voltage of comparer links to each other with comparer, comparer output links to each other with timer, the electric-controlled switch control signal links to each other with timer, and the timer metering discharges and recharges the time; Above-mentioned resistance can change inductive bank into and become the LC charging and discharging circuit to come inductance measuring and electric capacity; Described electric-controlled switch, but a plurality of series connection survey sensor of its electric-controlled switch matrix.
The present invention fills (putting) electric process by electric capacity-resistance or electric capacity-inductance will be converted to metering to the time to the metering of component value.What the present invention includes that one group of electric capacity-resistance or the electric capacity-inductance electric-controlled switch by controller control couples together fills (putting) electric loop, voltage and comparator reference voltage (being normal voltage) compare on the capacitor, and the comparer output voltage is converted to the time timing by timer.Fill in (putting) electricity, capacitance, resistance value, inductance value all are directly proportional with the time, by filling the value that (putting) electricity measures electric capacity, resistance, inductance to the time of reference voltage.The present invention has the following advantages with common technology ratio:
This circuit assembly is originally less than 10 yuan, less than the price of AD0809 A/D chip.
This circuit realizes that synthesis precision is better than 0.5%.
Conventional method is by transducer and amplifier its conversion to be enlarged into voltage to carry out conversion by the A/D circuit again, as the needs multichannel measurement, then need a plurality of transducers, amplifier and corresponding circuit-changing switch, circuit is with regard to more complicated like this, components and parts are many, and cost is also higher.The present invention adopts simple digital circuit to realize electric capacity, resistance, inductance value are converted to numeral, increase to measure passage and does not increase circuit substantially and can carry out conversion.The conventional method wiring can't be shared, and measurement circuit needs the 2n bar at least, and the present invention can a shared line, and measurement circuit need only the n+1 bar, thereby has saved circuit fee usefulness.(n is the detected element number)
The common mould of conventional method/number circuit is outside microprocessor, need interface circuit test data could be sent into microprocessor, and this method can be used the timer of microprocessor, saves interface circuit, thereby saved limited external interface and the lead-in wire of processor, can make circuit smaller and more exquisite.
The present invention can identification sensor whether short circuit or open circuit.
Circuit used herein all adopts digital circuit, has avoided adopting simulation, two kinds of costs that circuit improved of numeral.The present invention is described in more detail below in conjunction with accompanying drawing and example.
The course of work of the present invention is: referring to accompanying drawing 1, the circuit virgin state: voltage 24 is not equal to voltage 17, reference voltage 25 (normal voltage) value is between the voltage 24,17 and is relatively stable, and electric-controlled switch 14,15,16 can be received capacitor 1,2,3 to form on resistance 4 or the voltage 17 and fill (putting) electric loop.Beginning, controller 27 control electric-controlled switchs 14 are connected resistance 4, electric-controlled switch 18 is connected resistance 4, timer 12 is opened, voltage 24 forms and fills (putting) electric loop by electric-controlled switch 18, resistance 4, electric-controlled switch 14, capacitor 1, voltage 13, capacitor 1 piezoelectricity that powers on presses 10 to compare with comparer 26 reference voltages 25, and comparer 26 output voltages 11 are given timer 12 and converted the time timing to.Then, when voltage 10 liters (or falling) when equating with voltage 25, controller 27 control timers 12 are closed, and control electric-controlled switch 18 simultaneously and disconnect, electric-controlled switch 14 connection voltages 17 are for electric capacity 1 is put (filling).By that analogy, can read filling (putting) electricity time of electric capacity-resistance from timer 12.Should guarantee in the test process that voltage 24,25,17,13 is stable.
Fill (putting) electric formula as can be known by resistance-capacitance or inductor-capacitor: electric capacity was directly proportional with the duration of charging, resistance-capacitance concussion formula τ=-ln[1-Vc/ (V1-V2)] RC, be C=τ/-ln[1-Vc/ (V1-V2)] R, τ is second for filling (putting) electric chronomere in the formula, C is that unit of capacity is a farad, R is that unit of resistance is ohm, Vc is a reference voltage 25, V1 is a voltage 24, V2 is that voltage 17 units are volt, thereby with the nonlinear relation transformation of voltage in the charging process and time is the linear relationship of electric capacity and time, at resistance 4, voltage 25,24,17, under the 13 known situations, capacitor value can be obtained.In like manner, capacitor is known, and other voltages are known, and resistance value also can be obtained.Inductance acts on equivalence and is resistance in filling (putting) electric process, fill (putting) electric formula as can be known by electric capacity-inductance, inductance value with fill (putting) electricity and time also be directly proportional, so, electric capacity-inductance can be filled that voltage and the nonlinear relation transformation of time are the linear relationship of inductance and time in (putting) electric process,, can obtain inductance value by known each capacitor value, magnitude of voltage, the known electric sensibility reciprocal can be obtained capacitor value.It is different to utilize resistance and inductance that the electric capacity of different sizes are filled (putting) electric effect, can obtain the resistance, the inductance value that vary in size.Filling in (putting) electric formula: ln[1-Vc/ (V1-V2)] R is constant, electric capacity adopts part of standards electric capacity in the ifs circuit, its numerical value is known, by measurement standard electric capacity charging (or discharge) time, calculate the corresponding relation formula of different capacitors value and time, so, the measured capacitance device is replaced standard capacitance fill (putting) electricity in just filling (putting) electric loop, then can directly try to achieve measured capacitance device value by the time of timer output to reference voltage.Needn't know resistance 4, voltage 24,25,17,13 concrete numerical value in this way, as long as they are stable.In like manner, adopt part of standards resistance, the part of standards inductance can be obtained other measured resistance, inductance value.Test middle controller may command is organized electric-controlled switch more, is used to measure more multisensor thereby can form test matrix.What deserves to be explained is that above-mentioned electric capacity, resistance, inductance all can have several, this embodiment only draws three to every kind, in addition matrix can with two dimension or two dimension is above.Accompanying drawing 2 is a kind of application integration element schematic diagram of the present invention, wherein, divider resistance 32,33 provides comparative voltage 25, MC4053 on-off element 29 comprises electric-controlled switch 14,15,16, MC4051 on-off element 30 comprises electric-controlled switch 18,19,20,21,22,23, AT89F2051 single-chip microcomputer 31 includes comparer 26, counter 12, controller 27, and single-chip microcomputer 31 is by connecting line 28,34 gauge tap elements 29 and 30.
The present invention can form the circuit that capacitor value is converted to numeral.
The course of work is referring to accompanying drawing 3, the circuit virgin state: voltage 24 is not equal to voltage 17, reference voltage 25 values are between the voltage 24,17 and are relatively stable, and electric-controlled switch 14,15,16 can be received capacitor 1,2,3 to form on resistance 4 or the voltage 17 and fill (putting) electric loop.Beginning, controller 27 control electric-controlled switchs 14 are connected resistance 4, timer 12 is opened, voltage 24 fills (putting) by resistance 4, electric-controlled switch 14, capacitor 1, voltage 13 for capacitor 1, capacitor 1 piezoelectricity that powers on presses 10 to compare with comparer 26 reference voltages 25, and comparer 26 output voltages 11 are given timer 12 and converted the time timing to.Then, when voltage 10 liters (or falling) when equating with voltage 25, controller 27 control timers 12 are closed, electric-controlled switch 14 connection voltages 17 are for electric capacity 1 is put (filling).By that analogy, can read filling (putting) electricity time of capacitor from timer 12.Should guarantee in the test process that voltage 24,25,17,13 is stable.Same as above, can try to achieve capacitor value.
The present invention can form the circuit that resistor values is converted to numeral.
The course of work is referring to accompanying drawing 5, and the circuit virgin state: voltage 24 is not equal to voltage 17, and reference voltage 25 (normal voltage) value is between the voltage 24,17 and is relatively stable, and electric-controlled switch 14 can be received capacitor 1 to form on the voltage 17 and fill (putting) electric loop.Beginning, controller 27 control electric-controlled switchs 18 are connected resistance 4, electric-controlled switch 14 disconnects, timer 12 is opened, voltage 24 forms and fills (putting) electric loop by electric-controlled switch 18, resistance 4, capacitor 1, voltage 13, capacitor 1 piezoelectricity that powers on presses 10 to compare with comparer 26 reference voltages 25, and comparer 26 output voltages 11 are given timer 12 and converted the time timing to.Then, when voltage 10 liters (or falling) when equating with voltage 25, controller 27 control timers 12 are closed, and control electric-controlled switch 18 simultaneously and disconnect, electric-controlled switch 14 connection voltages 17 are for electric capacity 1 is put (filling).By that analogy, can read filling (putting) electricity time of electric capacity-resistance from timer 12.Should guarantee in the test process that voltage 24,25,17,13 is stable.Same as above, can try to achieve resistor values.
The present invention can form the circuit that inductor value is converted to numeral.
The course of work is referring to accompanying drawing 7, and the circuit virgin state: voltage 24 is not equal to voltage 17, and reference voltage 25 (normal voltage) value is between the voltage 24,17 and is relatively stable, and electric-controlled switch 14 can be received electric capacity 1 to form on the voltage 17 and fill (putting) electric loop.Beginning, controller 27 control electric-controlled switchs 14 disconnect, electric-controlled switch 21 is connected inductance 7, timer 12 is opened, voltage 24 forms and fills (putting) electric loop by electric-controlled switch 21, resistance 4, capacitor 1, voltage 13, capacitor 1 piezoelectricity that powers on presses 10 to compare with comparer 26 reference voltages 25, and comparer 26 output voltages 11 are given timer 12 and converted the time timing to.Then, when voltage 10 liters (or falling) when equating with voltage 25, controller 27 control timers 12 are closed, and control electric-controlled switch 21 simultaneously and disconnect, electric-controlled switch 14 connection voltages 17 are for electric capacity 1 is put (filling).By that analogy, can read filling (putting) electricity time of electric capacity-resistance from timer 12.Should guarantee in the test process that voltage 24,25,17,13 is stable.Same as above, can try to achieve inductor value.
More than in each circuit diagram switch can replace by the equivalent electrical circuit of switch, as the MOS switching device, triode switch device etc.
Utilize some fault that above circuit can also decision element, for example, when timing is 0, can judge measured capacitance device open circuit, or measured resistance, inductance short circuit.When timing is infinity, can judge short circuit of measured capacitance device or measured resistance, inductance open circuit.
As shown in Figure 9, this is a two-dimensional matrix, and after the series connection of four electric-controlled switchs, horizontal switch and longitudinal switch are opened simultaneously can resistance of gating, can survey this sensor matrices by horizontal switch and longitudinal switch combination.
Claims (2)
1. electric capacity, resistance, the inductance digital conversion circuit, by electric capacity, inductance, resistance, comparer, timer, controller, electric-controlled switch is formed, it is characterized in that: each electric capacity, resistance all links to each other with the electric-controlled switch of controller control, controller can be formed the capacitance-resistance charging and discharging circuit by electric-controlled switch control capacitance gating resistance, but measuring resistance and electric capacity, the end that electric capacity links to each other with resistance links to each other with comparer, the reference voltage of comparer links to each other with comparer, comparer output links to each other with timer, the electric-controlled switch control signal links to each other with timer, the timer metering discharges and recharges the time, and described resistance can change inductive bank into and become the LC charging and discharging circuit to come inductance measuring and electric capacity.
2. according to the described a kind of electric capacity of claim 1, resistance, inductance digital conversion circuit, it is characterized in that: described electric-controlled switch, but a plurality of series connection survey sensor of its electric-controlled switch matrix.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99119404 CN1131436C (en) | 1999-09-21 | 1999-09-21 | Circuit to convert capacitance, resistance and inductance into digital amount |
| PCT/CN2000/000185 WO2001022595A1 (en) | 1999-09-21 | 2000-06-30 | A digital circuit for converting a capacitance value, a resistance value and an inductance value to digital values |
| AU58010/00A AU5801000A (en) | 1999-09-21 | 2000-06-30 | A digital circuit for converting a capacitance value, a resistance value and an inductance value to digital values |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99119404 CN1131436C (en) | 1999-09-21 | 1999-09-21 | Circuit to convert capacitance, resistance and inductance into digital amount |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1289048A CN1289048A (en) | 2001-03-28 |
| CN1131436C true CN1131436C (en) | 2003-12-17 |
Family
ID=5280884
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 99119404 Expired - Fee Related CN1131436C (en) | 1999-09-21 | 1999-09-21 | Circuit to convert capacitance, resistance and inductance into digital amount |
Country Status (3)
| Country | Link |
|---|---|
| CN (1) | CN1131436C (en) |
| AU (1) | AU5801000A (en) |
| WO (1) | WO2001022595A1 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7460441B2 (en) * | 2007-01-12 | 2008-12-02 | Microchip Technology Incorporated | Measuring a long time period |
| CN102253286A (en) * | 2011-06-27 | 2011-11-23 | 郑军 | Resistance/capacitance measuring method and device thereof |
| CN103308842A (en) * | 2012-03-07 | 2013-09-18 | 鸿富锦精密工业（深圳）有限公司 | Debugging circuit |
| CN102621399B (en) * | 2012-04-23 | 2014-07-02 | 欧阳斌林 | Inductance measuring method based on switching circuit |
| CN103513106A (en) * | 2012-06-26 | 2014-01-15 | 中兴通讯股份有限公司 | Measuring method, measuring circuit and monitoring apparatus |
| CN104730341A (en) * | 2015-03-10 | 2015-06-24 | 昆山龙腾光电有限公司 | Impedance detection circuit and displayer detection device and method |
| CN108627701A (en) * | 2017-03-15 | 2018-10-09 | 上海骐宏电驱动科技有限公司 | Resistance measurement system and resistance measuring equipment |
| CN109935181A (en) * | 2017-12-19 | 2019-06-25 | 上海和辉光电有限公司 | A kind of driving circuit, the method and display for detecting connecting component impedance |
| CN108982972A (en) * | 2018-08-22 | 2018-12-11 | 西安飞芯电子科技有限公司 | A kind of micro- inductance measurement method and apparatus |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4492916A (en) * | 1979-07-20 | 1985-01-08 | Johnson Benjamin A | Digital meter using calculator components |
| FR2495782A1 (en) * | 1980-12-05 | 1982-06-11 | Accumulateurs Fixes | RESISTANCE MEASUREMENT CIRCUIT |
| US4864513A (en) * | 1987-07-07 | 1989-09-05 | Honeywell Incorporated | Potentiometer setting detection by measuring the ratio of RC time constants |
| US4841458A (en) * | 1987-07-07 | 1989-06-20 | Honeywell, Incorporated | Analog to digital conversion by measuring the ratio of RC time constants |
| FR2625822B1 (en) * | 1988-01-13 | 1994-04-15 | Ciapem | DEVICE FOR ENTERING DATA INTO A MICROPROCESSOR, PARTICULARLY FOR CONTROLLING A HOUSEHOLD APPLIANCE |
| WO1990012459A1 (en) * | 1989-03-31 | 1990-10-18 | Digital Appliance Controls, Inc. | Analog to digital converter |
| US4987372A (en) * | 1989-08-01 | 1991-01-22 | Lutron Electronics Co., Inc. | Potentiometer state sensing circuit |
| KR920009206B1 (en) * | 1990-01-25 | 1992-10-14 | 삼성전자 주식회사 | Integration type audio/digital converter control circuit |
| DE4020732A1 (en) * | 1990-06-29 | 1992-01-09 | Pilz Gmbh & Co | Manual analog input circuitry for microprocessor, etc. - has charge circuit with DC voltage source for included capacitor, with start switches |
| FR2679339B1 (en) * | 1991-07-18 | 1994-12-09 | Sagem | METHOD FOR MEASURING A RESISTANCE BY EVALUATING THE CHARGING TIME OF A CAPACITOR. |
| AT401985B (en) * | 1991-09-19 | 1997-01-27 | Vaillant Gmbh | ANALOG-DIGITAL CONVERTER |
| US5479103A (en) * | 1994-01-18 | 1995-12-26 | Air Communications, Inc. | Non-linear voltage measuring implementing capacitor charging time |
| FR2718242B1 (en) * | 1994-04-01 | 1996-05-03 | Schlumberger Ind Sa | Circuit for measuring a physical quantity. |
| EP0701687B1 (en) * | 1994-04-05 | 1999-07-28 | Koninklijke Philips Electronics N.V. | Resistance measuring circuit, and thermal appliance, electrical thermometer and cold-generating appliance including such a measuring circuit |
| DE4423955A1 (en) * | 1994-07-07 | 1996-01-11 | Bosch Gmbh Robert | Method for analog / digital conversion of an electrical signal and device for carrying out the method |
| JPH11153632A (en) * | 1997-11-20 | 1999-06-08 | New Japan Radio Co Ltd | Resistance measuring device |
-
1999
- 1999-09-21 CN CN 99119404 patent/CN1131436C/en not_active Expired - Fee Related
-
2000
- 2000-06-30 AU AU58010/00A patent/AU5801000A/en not_active Abandoned
- 2000-06-30 WO PCT/CN2000/000185 patent/WO2001022595A1/en active Application Filing
Also Published As
| Publication number | Publication date |
|---|---|
| WO2001022595A1 (en) | 2001-03-29 |
| CN1289048A (en) | 2001-03-28 |
| AU5801000A (en) | 2001-04-24 |
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