CN205176142U - Inductance measurement circuit - Google Patents
Inductance measurement circuit Download PDFInfo
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- CN205176142U CN205176142U CN201520863695.6U CN201520863695U CN205176142U CN 205176142 U CN205176142 U CN 205176142U CN 201520863695 U CN201520863695 U CN 201520863695U CN 205176142 U CN205176142 U CN 205176142U
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- circuit
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- chip microcomputer
- power supply
- inductance
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Abstract
The utility model discloses an inductance measurement circuit, this inductance measurement circuit comprises pulse control circuit, step pulse circuit, effect voltage circuit, benchmark voltage circuit, display circuit, singlechip and comparison circuit, pulse control circuit's output is connected with step pulse circuit's the input and the output of singlechip respectively, step pulse circuit's output is connected with the input that acts on voltage circuit and singlechip respectively, effect voltage circuit's output is connected with comparison circuit's input, and benchmark voltage circuit's output is connected with comparison circuit's input, comparison circuit's output is connected with the input of singlechip, the output of singlechip is connected constitution inductance measurement circuit with the input of display circuit. The utility model discloses the electricity is surveyed the measuring circuit and is had measurement accuracy height, fast, and circuit structure is simple, the component is few, easy operation, advantages such as measuring result automatic display.
Description
Technical field:
The utility model relates to a kind of metering circuit, uses when being specially adapted to inductance measurement.
Background technology:
Under the occasion of circuit design, scientific research personnel is to various circuit modeling, emulation, calculating, need the size of the inductance value accurately understanding multiple inductive reactive element, traditional measuring method measures the alternating-current parameter of inductor, utilizes the approximate formula derived to calculate.Not only circuit structure is complicated, use element is many, production cost is high for the measuring instrument designed based on this measuring method, and measuring error is also larger; Other high-precision digital measuring instruments, mostly expensive again, be difficult to popularize.
Summary of the invention:
Task of the present utility model is to provide that a kind of circuit unit is few, the inductance measurement circuit of Quick Measurement.
Task of the present utility model completes like this: a kind of inductance measurement circuit, it is characterized in that: this inductance measurement circuit is by pulse control circuit, step pulse circuit, applied voltage circuit, reference voltage circuit, display circuit, single-chip microcomputer and comparator circuit are formed, the output terminal of described pulse control circuit is connected with the output terminal of single-chip microcomputer with the input end of step pulse circuit respectively, the output terminal of described step pulse circuit is connected with the input end of single-chip microcomputer with applied voltage circuit respectively, the described output terminal of applied voltage circuit is connected with the input end of comparator circuit, the output terminal of reference voltage circuit is connected with the input end of comparator circuit, the output terminal of described comparator circuit is connected with the input end of single-chip microcomputer, the output terminal of described single-chip microcomputer and the input end of display circuit are connected to form inductance measurement circuit.Described pulse control circuit is connected by resistance R5 and photo-coupler No. 2 pins by the pin P1 on single-chip microcomputer, and photo-coupler No. 3 pins are connected with resistance R1, and resistance R1 is also connected with C point, constitutes described pulse control circuit.C point on described step pulse circuit is connected with triode Q1 base stage, triode Q1 emitter is connected with power supply ground, triode Q1 collector is connected with power supply VCC by diode D1, wherein diode D1 is reverse-bias state, the coils from parallel connection of coils of diode D1 two ends and relay R ELAY, the common of relay contact K1 connects step signal line STEP, and K1 normally closed contact connects power supply ground, K1 normally opened contact connects power supply VCC, constitutes described step pulse circuit.P1 on described applied voltage circuit is inductance detection head, and for connecting tested inductive element, step signal line STEP is connected with resistance R3 upper end, and resistance R3 lower end is connected with the upper end of tested inductance P1, and the lower end of tested inductance P1 is connected with power supply ground.Described reference voltage circuit is under the effect of step signal, and A point exports a certain size voltage, and its size of opposed power ground is
a point is also connected with No. 5 pins of voltage comparator U2B, and the upper end of adjustable resistance R2 is connected with power supply VCC, and the lower end of adjustable resistance R2 is connected with the upper end of resistance R6, and the lower end of resistance R6 is connected with power supply ground, constitutes described reference voltage circuit.
The utility model has following effect: the utility model electrical measurement metering circuit has that measuring accuracy is high, speed is fast, and circuit structure is simple, element is few, simple to operate, and measurement result such as to show automatically at the advantage.
Accompanying drawing illustrates:
Fig. 1 is pulse control circuit 1 structural representation; Fig. 2 is inductance measurement circuit structural representation; Fig. 3 is the block diagram of the technical program.
Embodiment:
The technical program is by pulse control circuit 1, step pulse circuit 2, applied voltage circuit 3, reference voltage circuit 4, display circuit 5, single-chip microcomputer 6, form with comparator circuit 7, (as shown in Figure 3) described pulse control circuit 1 is connected with the output terminal of single-chip microcomputer 6 with the input end of step pulse circuit 2 respectively, the output terminal of described step pulse circuit 2 is connected with the input end of applied voltage circuit 3 with single-chip microcomputer 6 respectively, the output terminal of described applied voltage circuit 3 is connected with the input end of comparator circuit 7, the output terminal of reference voltage circuit 4 is connected with the input end of comparator circuit 7, the output terminal of described comparator circuit 7 is connected with the input end of single-chip microcomputer 6, the output terminal of described single-chip microcomputer 6 and the input end of display circuit 5 are connected to form inductance measurement circuit.
The technical program inductance measurement circuit schematic diagram used as shown in Figure 2, its theoretical foundation is: tested inductance L 1 connected with resistance R3, carry out time-domain analysis to the loop of its composition, derive when inductance is under step signal effect after calculating, its both end voltage over time rule is
wherein E is the amplitude of step signal, and size equals power supply VCC, is 5V in the utility model.L is the size of tested inductance L 1, and R is the size of described resistance R3.Through calculating, as t=T, the voltage at described inductance L 1 two ends is U=0.3679E.In the technical program, U setting value is 1.8395V, and namely No. 6 pin voltage values of voltage comparator U2B are provided by the reference voltage circuit 4 that resistance R6, resistance R2 and power supply VCC are in series, and suitably adjustment power supply and resistance value are set to 1.8395V.In given step signal in a flash, the timer opening single-chip microcomputer 6 starts timing, and by No. 5 pin voltage of above-mentioned U (t) expression formula this transient voltage comparer known U2B higher than No. 6 pin voltage, therefore its U2B No. 7 pins export as high level.No. 7 pins of voltage comparator U3B are connected with single-chip microcomputer 6, and As time goes on, when the magnitude of voltage at inductance L 1 two ends is lower than setting value, voltage comparator No. 7 pin upsets, will trigger the interrupt mechanism of single-chip microcomputer 6, single-chip microcomputer 6 stops timing.The computing formula deriving described inductance L 1 is L=t × R, and time t single-chip microcomputer 6 is accurately measured, and described resistance R3 is the resistance of the known resistance of high precision, therefore the size of described inductance L 1 can directly be calculated by single-chip microcomputer 6.
Pulse control circuit 1 as shown in Figure 1 and step pulse circuit 2, when the P1 pin of single-chip microcomputer 6 is set to low level, photo-coupler U1 conducting, the base voltage of triode Q1, base current significantly improves, make triode Q1 conducting, relay K 1 coil circuit invocation point, its normally opened contact closes, namely relay No. 1 pin is received on power supply VCC, obtain an effective step signal, namely step pulse circuit 2 produces a step signal, after this step signal produces, the series loop acting on single-chip microcomputer 6 simultaneously and be made up of resistance R3 and tested inductance, timer opened by single-chip microcomputer 6, the voltage that described applied voltage circuit 3 and described reference voltage circuit 4 produce simultaneously is sent into described comparator circuit 7 and is carried out numeric ratio comparatively, and single-chip microcomputer 6 is delivered in the output of comparator circuit 7, when the comparative result that single-chip microcomputer 6 receives is high level, timer keeps timing, otherwise stopping timing, and single-chip microcomputer 6 pin P1 is set to noble potential, record timing time is t, single-chip microcomputer 6 is according to timing time t, the resistance R3 of known resistance, the formula of deriving, calculate, and result is shown by display circuit 5, a measuring period completes.
Described pulse control circuit 1 as shown in Figure 1, pin P1 on single-chip microcomputer 6 is connected by resistance R5 and photo-coupler No. 2 pins, photo-coupler No. 3 pins are connected with resistance R1, resistance R1 is also connected with C point, constitute described pulse control circuit 1, by pulse control circuit 1, the interference free performance of single-chip microcomputer 6 can be improved.
Described step pulse circuit 2 as shown in Figure 1, C point is connected with triode Q1 base stage, triode Q1 emitter is connected with power supply ground, triode Q1 collector is connected with power supply VCC by diode D1, and wherein diode D1 is the coils from parallel connection of coils of reverse-bias state, diode D1 two ends and relay R ELAY, the common of relay contact K1 connects step signal line STEP, K1 normally closed contact connects power supply ground, and K1 normally opened contact connects power supply VCC, constitutes described step pulse circuit 2.
When the pin P1 on single-chip microcomputer 6 is high level, photo-coupler U1 closes, triode Q1 closes, relay R ELAY coil almost no current passes through, relay contact K1 attonity, the common STEP ground connection of K1, the common STEP state that single-chip microcomputer 6 detects K1 is 0, when single-chip microcomputer 6 pin P1 as required, when acting as low level, photo-coupler U1 conducting, triode Q1 conducting, relay R ELAY coil is by enough electric currents, relay contact K1 action, after action, the common STEP of K1 meets power supply VCC, the state that single-chip microcomputer 6 detects K1 common STEP is 1, carry out rapidly other logical operations and interface process.When STEP becomes 1 state from 0 state, be regarded as a step signal.
Described applied voltage circuit 3 as shown in Figure 2, P1 is inductance detection head, for connecting tested inductive element, inductance value size is L, step signal line STEP is connected with resistance R3 upper end, resistance R3 lower end A point is connected with the upper end of tested inductance P1, and the lower end of tested inductance P1 is connected with power supply ground, constitutes described applied voltage circuit 3.The A point of described applied voltage circuit 3 is connected with No. 5 pins of operational amplifier U2B, measuring voltage is given comparator circuit 7 and compares with reference voltage.
Described reference voltage circuit 4 as shown in Figure 2, the upper end of adjustable resistance R2 is connected with power supply VCC, the lower end B point of adjustable resistance R2 is connected with the upper end of resistance R6, the lower end of resistance R6 is connected with power supply ground, constitute described reference voltage circuit 4, by regulating the resistance size of adjustable resistance R2, can change the current potential size of B point, the current potential of B point is adjusted to 1.8395V by the utility model.The B point of described reference voltage circuit 4 is connected with No. 6 pins of operational amplifier U2B, for comparator circuit 7 provides reference voltage.
Described comparator circuit 7 as shown in Figure 2, No. 5 pins of operational amplifier U2B and No. 6 pins lower end A point of contact resistance R3 and the upper end B point of resistance R6 respectively, No. 8 pins are connected power supply VCC and ground respectively with No. 4 pins, No. 7 pins of U2B are connected with single-chip microcomputer 6 pin P2, also be connected with the lower end of resistance R4 simultaneously, the upper end of resistance R4 is connected with power supply VCC, constitutes described comparator circuit 7.The effect of comparator circuit 7 is compared the size of the current potential of the current potential of A point and B point, and comparative result is sent into single-chip microcomputer 6 and process.The power supply VCC size of the technical program is 5V, from described applied voltage circuit 3, resistance R3 and tested inductance are series relationship, time-domain analysis is carried out in this series loop, obtain a result to rise at a moment of being subject to step signal excitation for: from then on series loop and carry out timing, export useful signal to described voltage comparator circuit 7 to end to single-chip microcomputer 6 pin P2, between the resistance R of timing time t and resistance R3, tested inductance value size L, have fixing mathematical relation, i.e. L=t × R.
The one-piece construction schematic block diagram of the technical program as shown in Figure 3, its P1 pin is set to low level by single-chip microcomputer 6, control described step pulse circuit 2 and produce a step signal, after this step signal produces, the series loop acting on single-chip microcomputer 6 simultaneously and be made up of resistance R3 and tested inductance, timer opened by single-chip microcomputer 6, the voltage that described applied voltage circuit 3 and described reference voltage circuit 4 produce simultaneously is sent into described comparator circuit 7 and is carried out numeric ratio comparatively, after single-chip microcomputer 6 have received the object information of described comparator circuit 7 transmission, rapid stopping timing, and single-chip microcomputer 6 pin P1 is set to noble potential, record timing time is t, single-chip microcomputer 6 is according to timing time t, the resistance R3 of known resistance, the formula of deriving, calculate, and result is shown by display circuit 5, a measuring period completes.
The above is only the preferred implementation of the technical program; it should be pointed out that for those skilled in the art, under the prerequisite not departing from the technical program know-why; can also make some improvement, these improve the protection domain that also should be considered as the technical program.
Claims (5)
1. an inductance measurement circuit, it is characterized in that: this inductance measurement circuit is by pulse control circuit, step pulse circuit, applied voltage circuit, reference voltage circuit, display circuit, single-chip microcomputer and comparator circuit are formed, the output terminal of described pulse control circuit is connected with the output terminal of single-chip microcomputer with the input end of step pulse circuit respectively, the output terminal of described step pulse circuit is connected with the input end of single-chip microcomputer with applied voltage circuit respectively, the described output terminal of applied voltage circuit is connected with the input end of comparator circuit, the output terminal of reference voltage circuit is connected with the input end of comparator circuit, the output terminal of described comparator circuit is connected with the input end of single-chip microcomputer, the output terminal of described single-chip microcomputer and the input end of display circuit are connected to form inductance measurement circuit.
2. a kind of inductance measurement circuit according to claim 1, it is characterized in that: described pulse control circuit is connected by resistance R5 and photo-coupler No. 2 pins by the pin P1 on single-chip microcomputer, photo-coupler No. 3 pins are connected with resistance R1, resistance R1 is also connected with C point, constitutes described pulse control circuit.
3. a kind of inductance measurement circuit according to claim 1, it is characterized in that: the C point on described step pulse circuit is connected with triode Q1 base stage, triode Q1 emitter is connected with power supply ground, triode Q1 collector is connected with power supply VCC by diode D1, wherein diode D1 is reverse-bias state, the coils from parallel connection of coils of diode D1 two ends and relay R ELAY, the common of relay contact K1 connects step signal line STEP, K1 normally closed contact connects power supply ground, K1 normally opened contact connects power supply VCC, constitutes described step pulse circuit.
4. a kind of inductance measurement circuit according to claim 1, it is characterized in that: the P1 on described applied voltage circuit is inductance detection head, for connecting tested inductive element, step signal line STEP is connected with resistance R3 upper end, resistance R3 lower end is connected with the upper end of tested inductance P1, and the lower end of tested inductance P1 is connected with power supply ground.
5. a kind of inductance measurement circuit according to claim 1 or 4, is characterized in that: described reference voltage circuit is under the effect of step signal, and A point exports a certain size voltage, and its size of opposed power ground is
a point is also connected with No. 5 pins of voltage comparator U2B, and the upper end of adjustable resistance R2 is connected with power supply VCC, and the lower end of adjustable resistance R2 is connected with the upper end of resistance R6, and the lower end of resistance R6 is connected with power supply ground, constitutes described reference voltage circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520863695.6U CN205176142U (en) | 2015-11-03 | 2015-11-03 | Inductance measurement circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520863695.6U CN205176142U (en) | 2015-11-03 | 2015-11-03 | Inductance measurement circuit |
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| Publication Number | Publication Date |
|---|---|
| CN205176142U true CN205176142U (en) | 2016-04-20 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201520863695.6U Expired - Fee Related CN205176142U (en) | 2015-11-03 | 2015-11-03 | Inductance measurement circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105388364A (en) * | 2015-11-03 | 2016-03-09 | 新乡学院 | Inductance measurement circuit |
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2015
- 2015-11-03 CN CN201520863695.6U patent/CN205176142U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105388364A (en) * | 2015-11-03 | 2016-03-09 | 新乡学院 | Inductance measurement circuit |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20160420 Termination date: 20171103 |