CN217543234U - Precision voltage monitoring circuit suitable for high voltage - Google Patents
Precision voltage monitoring circuit suitable for high voltage Download PDFInfo
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- CN217543234U CN217543234U CN202221070946.1U CN202221070946U CN217543234U CN 217543234 U CN217543234 U CN 217543234U CN 202221070946 U CN202221070946 U CN 202221070946U CN 217543234 U CN217543234 U CN 217543234U
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Abstract
The precise voltage monitoring circuit suitable for high voltage comprises a first resistance network and a second resistance network which are connected between a detection end and the ground in series; the positive phase input end of the first operational amplifier is connected with the common end of the two resistance networks, and the negative phase input end of the first operational amplifier is connected with the output end; the output ends of the first operational amplifier and the second operational amplifier are respectively connected with two input ends of a differential ADC, and the output end of the differential ADC is used as the output end of the monitoring circuit. The utility model discloses a resistance network carries out synchronous partial pressure to the input high voltage, can improve the sampling precision, accomplishes the single-ended branch of sampling signal through two operational amplifier and carries out analog-to-digital conversion simultaneously, can further increase voltage sampling precision to reduce the circuit complexity, be favorable to improving the sampling precision and make things convenient for the back level to handle.
Description
Technical Field
The utility model belongs to the technical field of the electron, a voltage signal acquisition technique is related to, concretely relates to accurate voltage monitoring circuit suitable for it is highly compressed.
Background
In the specific application scene of multiple voltage acquisition occasions, high-precision acquisition of high-voltage signals is required, the detection precision of voltage detection means commonly used in the market at present is in the level of 0.2%, when the acquisition voltage level is 1000V, the identification error reaches 2V or even higher, and under the condition of the sampling precision, the precision control and operation are difficult to realize. In many scenes, the precision of the precision monitoring voltage needs to reach 0.01 percent or even higher, namely the measurement error needs to be controlled within 100mV when the 1000V high voltage is monitored, but the existing device has no product capable of achieving the performance, and although the individual customized product can realize high-precision detection, the price is high, and the customized product cannot be used in a large scale.
SUMMERY OF THE UTILITY MODEL
For overcoming the technical defect that prior art exists, the utility model discloses a be applicable to highly compressed accurate voltage monitoring circuit.
The utility model discloses a be applicable to high-voltage accurate voltage monitoring circuit, including the first resistance network and the second resistance network of establishing ties between sense terminal and ground, two resistance networks are connected in parallel by a plurality of rated resistance the same resistance and are constituteed;
the positive phase input end of the first operational amplifier is connected with the common end of the two resistance networks, and the negative phase input end of the first operational amplifier is connected with the output end;
the positive phase input end of the second operational amplifier is connected with a first reference voltage, and the inverting input section of the second operational amplifier is connected with the output end of the first operational amplifier through a first resistor and is connected with the output end of the second operational amplifier through a second resistor;
the output ends of the first operational amplifier and the second operational amplifier are respectively connected with two input ends of a differential ADC, and the output end of the differential ADC is used as the output end of the monitoring circuit.
Preferably, the differential ADC further comprises a reference voltage module, wherein the reference voltage module outputs the first reference voltage and outputs a second reference voltage to the differential ADC.
Preferably, the differential ADC is CS1231.
Preferably, the first operational amplifier and the second operational amplifier are HTC8289.
Preferably, the sampling reference voltage of the differential ADC is a voltage value twice the first reference voltage.
Preferably, the resistor network is formed by connecting more than 100 resistors with the same rated resistance in parallel.
Adopt be applicable to highly compressed accurate voltage monitoring circuit, adopt resistance network to carry out synchronous partial pressure to the input high voltage, can improve the sampling precision, accomplish the single-ended branch of sampling signal through two operational amplifier simultaneously and carry out analog-to-digital conversion, can further increase voltage sampling precision to reduce circuit complexity, be favorable to improving the sampling precision and make things convenient for the back level to handle, the utility model discloses each device can adopt common volume production device in the circuit, realizes the high accuracy after the combination and detects, the cost is reduced.
Drawings
Fig. 1 is a schematic diagram of an embodiment of a precise voltage monitoring circuit suitable for high voltage according to the present invention;
the reference numbers in the figures refer to: BG-reference voltage module, VX-detection terminal, RP 1-first resistance network, RP 2-second resistance network, AMP 1-first operational amplifier, AMP 2-second operational amplifier, R1-first resistance, R2-second resistance, OUT 1-first operational amplifier output voltage, OUT 2-second operational amplifier output voltage, VREF 1-first reference voltage, VREF 2-second reference voltage, D-ADC-differential ADC, OUT-monitoring circuit output voltage.
Detailed Description
The following describes the present invention in further detail with reference to the accompanying drawings.
The utility model discloses a be applicable to high-voltage accurate voltage monitoring circuit, including the first resistance network and the second resistance network of establishing ties between sense terminal and ground, two resistance networks are connected in parallel by a plurality of rated resistance the same resistance and are constituteed;
the positive phase input end of the first operational amplifier is connected with the common end of the two resistance networks, and the negative phase input end of the first operational amplifier is connected with the output end;
the positive phase input end of the second operational amplifier is connected with a first reference voltage, and the negative phase input section of the second operational amplifier is connected with the output end of the first operational amplifier through a first resistor and connected with the output end of the second operational amplifier through a second resistor;
the output ends of the first operational amplifier and the second operational amplifier are respectively connected with two input ends of a differential ADC, and the output end of the differential ADC is used as the output end of the monitoring circuit.
As known to those skilled in the art, nominal values of rated resistors are the same, but resistance values of resistors actually produced in batch in an industrial manner have a certain difference, the first resistor network and the second resistor network can greatly improve resistance accuracy by connecting a plurality of resistors in parallel, and obtain a resistance value with a very small error, for example, a single 1000 ohm rated resistor has an error of 1%, and an actual resistance value obtained by connecting 100 identical resistors in parallel is 10 ohms, and according to an error theoretical analysis, an error of 100 parallel resistors can be obtained to be less than 0.1 ohm, and is greatly reduced to less than 1% compared with an error of 5% of a single resistor. By adjusting the magnitude of the single resistance rated value of the first resistance network and the second resistance network, the voltage of the detection end can be divided, for example, 99:1, the voltage value of 1% detection end can be output at the common end of the two resistance networks.
As shown in fig. 1, the voltage divided by the two resistor networks is input to the first operational amplifier and the second operational amplifier, in the specific circuit shown in fig. 1, the conversion of the single-ended signal into the differential signal output is realized by the two operational amplifiers, when the resistance values of the first resistor and the second resistor are equal, the voltages of the two input ends are equal according to the operating principle of the operational amplifiers, and OUT1-OUT2= 2 out1-2 VREF2 can be calculated, wherein OUT1, OUT2, and VREF2 respectively represent the output voltage of the first operational amplifier, the output voltage of the second operational amplifier, and the second reference voltage. The first operational amplifier enables the output voltage of the first operational amplifier to be equal to the voltage of the non-inverting input end of the first operational amplifier, a pair of differential signals can be obtained through the two operational amplifiers, the differential signals are only related to the voltage of the input end of the first operational amplifier, the voltage is equal to the voltage of the detection end, the differential signals are obtained through voltage division and sampling, and the pair of differential voltages can adjust the voltage difference value of the differential signals through the second reference voltage.
The first operational amplifier AMP1 outputs a voltage OUT1 to one sampling end of the differential ADC, and the second operational amplifier AMP2 outputs a voltage OUT2 to the other sampling end of the differential ADC, so that the synchronous signal conversion and the single-end to differential conversion of the detection end VX are completed.
In the embodiment shown in fig. 1, while one reference voltage block BG supplies the second reference voltage to the differential ADC as a sampling reference, it outputs the first reference voltage to the non-inverting input terminal of the second operational amplifier AMP2, so that the differential ADC output can always operate at about the reference point of the first reference voltage. Preferably, the voltage value of the first reference voltage is half of the voltage value of the second reference voltage, so that the sampling reference voltage of the differential ADC is about twice the input voltage, and the sampling effect is the best.
In a specific embodiment, a voltage of 1000V is divided by resistor networks RP1 and RP2 to obtain 500mV, assuming that the feedback accuracy of two operational amplifiers is 1%, that is, the maximum difference between the output OUT1 of AMP1 and the output OUT2 of AMP2 is 500mv × 2% =10mV, and the differential ADC uses CS1231 with 24 bits to collect 20-th-power data with 20 bits, that is, 2 bits. Finally, 510mv/2^20=5.1 × 10 can be calculated -4 mv; sampling error of 5.1 x 10 -4 mv /1000V=5.1*10 -10 ;
Adopt be applicable to highly compressed accurate voltage monitoring circuit, adopt resistance network to carry out synchronous partial pressure to the input high voltage, can improve the sampling precision, accomplish the single-ended branch of sampling signal through two operational amplifier simultaneously and carry out analog-to-digital conversion, can further increase voltage sampling precision to reduce circuit complexity, be favorable to improving the sampling precision and make things convenient for the back level to handle, the utility model discloses each device can adopt common volume production device in the circuit, realizes the high accuracy after the combination and detects, the cost is reduced.
In the foregoing, the preferred embodiments of the present invention, if not obviously contradictory or based on a certain preferred embodiment, can be combined and used by any superposition, the specific parameters in the embodiments and examples are only for the purpose of clearly expressing the verification process of the utility model, and are not used to limit the patent protection scope of the present invention, which is still based on the claims, and all the equivalent structural changes made by the contents of the specification and the drawings of the present invention should be included in the protection scope of the present invention.
Claims (6)
1. A precise voltage monitoring circuit suitable for high voltage is characterized by comprising a first resistor network and a second resistor network which are connected in series between a detection end and the ground, wherein the two resistor networks are formed by connecting a plurality of resistors with the same rated resistance in parallel;
the positive phase input end of the first operational amplifier is connected with the common end of the two resistance networks, and the negative phase input end of the first operational amplifier is connected with the output end;
the positive phase input end of the second operational amplifier is connected with a first reference voltage, and the inverting input section of the second operational amplifier is connected with the output end of the first operational amplifier through a first resistor and is connected with the output end of the second operational amplifier through a second resistor;
the output ends of the first operational amplifier and the second operational amplifier are respectively connected with two input ends of a differential ADC, and the output end of the differential ADC is used as the output end of the monitoring circuit.
2. The precision voltage monitoring circuit for high voltage of claim 1, further comprising a reference voltage module that outputs the first reference voltage and outputs a second reference voltage to a differential ADC.
3. The precision voltage monitoring circuit for high voltages of claim 1 wherein the differential ADC is CS1231.
4. The precise voltage monitoring circuit for high voltages of claim 1 wherein the first operational amplifier and the second operational amplifier are HTC8289.
5. The precision voltage monitoring circuit for high voltages of claim 1, wherein the sampled reference voltage of the differential ADC is twice the voltage value of the first reference voltage.
6. A precision voltage monitoring circuit according to claim 1 wherein the resistor network is formed by connecting more than 100 resistors of the same nominal resistance in parallel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221070946.1U CN217543234U (en) | 2022-05-07 | 2022-05-07 | Precision voltage monitoring circuit suitable for high voltage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221070946.1U CN217543234U (en) | 2022-05-07 | 2022-05-07 | Precision voltage monitoring circuit suitable for high voltage |
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| Publication Number | Publication Date |
|---|---|
| CN217543234U true CN217543234U (en) | 2022-10-04 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221070946.1U Active CN217543234U (en) | 2022-05-07 | 2022-05-07 | Precision voltage monitoring circuit suitable for high voltage |
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| CN (1) | CN217543234U (en) |
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- 2022-05-07 CN CN202221070946.1U patent/CN217543234U/en active Active
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