CN218003525U - Coil drive circuit and current sensor - Google Patents
Coil drive circuit and current sensor Download PDFInfo
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- CN218003525U CN218003525U CN202222006059.4U CN202222006059U CN218003525U CN 218003525 U CN218003525 U CN 218003525U CN 202222006059 U CN202222006059 U CN 202222006059U CN 218003525 U CN218003525 U CN 218003525U
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Abstract
The present application relates to a coil driving circuit and a current sensor, the coil driving circuit including: the output end of the compensation coil is grounded; an operational amplifier unit, a non-inverting input terminal of which is used for receiving an alternating voltage signal, an inverting input terminal of which is connected with the input terminal of the compensation coil, and configured to: generating a driving alternating voltage signal; a coil driving module, connected to both the output end of the operational amplifier unit and the input end of the compensation coil, configured to: and driving the compensation coil according to the driving alternating voltage signal so as to cancel the zero crossing point crossing distortion of the alternating voltage signal.
Description
Technical Field
The utility model relates to an electronic circuit technical field especially relates to a coil drive circuit and current sensor.
Background
A common emitter push-pull circuit is generally adopted in a compensation coil driving circuit of a traditional closed-loop current sensor, and due to the factor of PN node voltage drop of a triode, the output of an operational amplifier has the problem of zero crossing point cross-over distortion, so that the precision of the current sensor in measuring small signals is reduced.
However, in the prior art, a bias voltage is applied to make the triode weakly conductive, so that the influence of zero crossing cross distortion is reduced, but the method is influenced by temperature change, and static zero output is increased.
SUMMERY OF THE UTILITY MODEL
Accordingly, it is desirable to provide a coil driving circuit and a current sensor, which can eliminate the zero crossing point crossing distortion and improve the measurement accuracy of the small current driving of the compensation coil.
A first aspect of the present application provides a coil driving circuit including:
the output end of the compensation coil is grounded;
an operational amplifier unit, a non-inverting input terminal of which is used for receiving an alternating voltage signal, an inverting input terminal of which is connected with the input terminal of the compensation coil, and configured to: generating a driving alternating voltage signal;
a coil driving module, connected to both the output end of the operational amplifier unit and the input end of the compensation coil, configured to: and driving the compensation coil according to the driving alternating voltage signal so as to cancel zero crossing point crossing distortion of the alternating voltage signal.
In the coil driving circuit provided in the above embodiment, by providing the compensation coil, the operational amplifier unit, and the coil driving module, the output end of the compensation coil is grounded; an operational amplifier unit, a non-inverting input terminal of which is used for receiving an alternating current voltage signal, an inverting input terminal of which is connected with an input terminal of the compensation coil, and configured to: generating a driving alternating voltage signal; a coil driving module connected to both the output of the operational amplifier unit and the input of the compensation coil, and configured to: and driving the compensation coil according to the driving alternating voltage signal to cancel the zero crossing point crossing distortion of the alternating voltage signal and improve the precision of measuring a small driving current signal.
In one embodiment, the coil driving module includes:
a crossover distortion cancellation unit configured to: the first end of the operational amplifier unit is connected with the output end of the operational amplifier unit, and the second end of the operational amplifier unit is connected with the input end of the compensation coil;
a push-pull unit configured to: the first end of the operational amplifier unit is connected with the output end of the operational amplifier unit, the second end of the operational amplifier unit is connected with the positive power supply, the third end of the operational amplifier unit is connected with the negative power supply, and the fourth end of the operational amplifier unit is connected with the second end of the crossover distortion canceling unit.
In one embodiment, the push-pull unit includes:
a first switching tube configured to: the first end of the cross-over distortion cancellation unit is connected with the second end of the cross-over distortion cancellation unit, the second end of the cross-over distortion cancellation unit is connected with the output end of the operational amplifier unit, and the third end of the cross-over distortion cancellation unit is connected with the positive power supply;
a second switching tube configured to: the first end is connected with the second end of the crossover distortion canceling unit, the second end is connected with the output end of the operational amplifier unit, and the third end is connected with the negative power supply.
In one embodiment, when the driving current of the compensation coil is smaller than a preset current, the first switch tube and the second switch tube are both closed, and the driving alternating-current voltage signal is transmitted to the compensation coil through the crossover distortion cancellation unit.
In one embodiment, when the driving current of the compensation coil is greater than or equal to a preset current and the amplitude of the driving alternating voltage signal is in a positive half cycle, the first switching tube is turned on, and the second switching tube is turned off.
In one embodiment, when the driving current of the compensation coil is greater than or equal to a preset current and the amplitude of the driving alternating voltage signal is in a negative half cycle, the first switching tube is turned off and turned on, and the second switching tube is turned on.
In one embodiment, the first switch tube comprises an NPN transistor, and the second switch tube comprises a PNP transistor.
In one embodiment, the crossover distortion cancellation unit includes an adjustable resistor.
In one embodiment, the operational amplifier unit comprises an operational amplifier.
A second aspect of the present application provides a current sensor including the coil drive circuit described above.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain drawings of other embodiments without creative efforts based on the drawings.
Fig. 1 is a schematic circuit diagram of a coil driving circuit according to an embodiment of the present disclosure;
fig. 2 is a schematic circuit diagram of a coil driving circuit according to another embodiment of the present disclosure;
FIG. 3 is a schematic circuit diagram of a coil driving circuit according to another embodiment of the present application;
fig. 4 is a schematic circuit diagram of a coil driving circuit according to another embodiment of the present disclosure.
The reference numbers illustrate: 10. an operational amplifier unit; 20. a coil driving unit; 21. a crossover distortion canceling unit; 22. a push-pull unit; 221. a first switch tube; 222. and a second switch tube.
Detailed Description
To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are illustrated in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Where the terms "comprising," "having," and "including" are used herein, another component may be added unless a specific limiting term is used, such as "only," "consisting of 8230; \8230composition," etc. Unless mentioned to the contrary, singular terms may include the plural and are not to be construed as being one in number.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present application.
In this application, unless otherwise expressly stated or limited, the terms "connected" and "connecting" are used broadly and encompass, for example, direct connection, indirect connection via an intermediary, communication between two elements, or interaction between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.
In order to explain the technical solution of the present application, the following description will be given by way of specific examples.
In a coil driving circuit provided in an embodiment of the present application, as shown in fig. 1, the coil driving circuit includes a compensation coil L1, an operational amplifier unit 10, and a coil driving module 20. The output end of the compensation coil L1 is grounded; an operational amplifier unit 10, having a non-inverting input terminal for receiving an ac voltage signal IN and an inverting input terminal connected to the input terminal of the compensation coil L1, and configured to: generating a driving alternating voltage signal; a coil driving module 20, connected to both the output end of the operational amplifier unit 10 and the input end of the compensation coil L1, and configured to: and driving the compensation coil L1 according to the driving alternating voltage signal so as to cancel the zero crossing point crossing distortion of the alternating voltage signal.
In the coil driving circuit provided in the above embodiment, by providing the compensation coil, the operational amplifier unit, and the coil driving module, the output end of the compensation coil is grounded; an operational amplifier unit, a non-inverting input terminal of which is used for receiving an alternating voltage signal, an inverting input terminal of which is connected with the input terminal of the compensation coil, and configured to: generating a driving alternating voltage signal; a coil driving module, connected to both the output end of the operational amplifier unit and the input end of the compensation coil, configured to: and driving the compensation coil according to the driving alternating voltage signal to cancel the zero crossing point crossing distortion of the alternating voltage signal and improve the precision of measuring a small driving current signal.
In one embodiment, the operational amplifier unit 10 is configured to receive an ac voltage signal, perform impedance reduction processing on the ac voltage signal, and generate a driving ac voltage signal.
In one embodiment, as shown in fig. 2-4, the coil drive module includes: a crossover distortion canceling unit 21 and a push-pull unit 22. Specifically, the crossover distortion canceling unit 21 is configured to: the first end is connected with the output end of the operational amplifier unit 10, and the second end is connected with the input end of the compensation coil L1; the push-pull unit 22 is configured to: the first end is connected with the output end of the operational amplifier unit 10, the second end is connected with the positive power supply + DC, the third end is connected with the negative power supply-DC, and the fourth end is connected with the second end of the crossover distortion canceling unit 21. Wherein the arrows with filled hatchings indicate the current flow direction.
In one embodiment, with continued reference to fig. 2, the push-pull unit 22 includes: a first switch tube 221 and a second switch tube 222. Specifically, the first switch tube 221 is configured to: the first end is connected with the second end of the crossover distortion canceling unit 21, the second end is connected with the output end of the operational amplifier unit 10, and the third end is connected with the positive power supply + DC; the second switch tube 222 is configured to: the first end is connected with the second end of the crossover distortion canceling unit 21, the second end is connected with the output end of the operational amplifier unit 10, and the third end is connected with the negative power supply-DC.
In one embodiment, referring to fig. 2, when the driving current of the compensation coil L1 is smaller than a preset current, the first switch 221 and the second switch 222 are both turned off, and the driving ac voltage signal is transmitted to the compensation coil L1 through the crossover distortion cancellation unit 21.
In one embodiment, as shown in fig. 3, when the driving current of the compensation coil L1 is greater than or equal to the preset current and the amplitude of the driving ac voltage signal is at the positive half cycle, the first switching tube 221 is turned on, and the second switching tube 222 is turned off.
In one embodiment, as shown in fig. 4, when the driving current of the compensation coil L1 is greater than or equal to the preset current and the amplitude of the driving ac voltage signal is at the negative half cycle, the first switch tube 221 is turned off and turned on, and the second switch tube 222 is turned on.
As an example, the first switch tube 221 includes an NPN transistor, and the second switch tube 222 includes a PNP transistor.
As an example, the crossover distortion canceling unit 21 includes an adjustable resistor R1; the op-amp unit 10 includes an operational amplifier.
In an embodiment of the present application, there is also provided a current sensor including the coil driving circuit described above.
All possible combinations of the technical features of the above embodiments may not be described for the sake of brevity, but should be considered as within the scope of the present disclosure as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A coil driving circuit, comprising:
the output end of the compensation coil is grounded;
an operational amplifier unit, a non-inverting input terminal of which is used for receiving an alternating voltage signal, an inverting input terminal of which is connected with the input terminal of the compensation coil, and configured to: generating a driving alternating voltage signal;
a coil driving module, connected to both the output end of the operational amplifier unit and the input end of the compensation coil, configured to: and driving the compensation coil according to the driving alternating voltage signal so as to cancel zero crossing point crossing distortion of the alternating voltage signal.
2. The coil drive circuit according to claim 1, wherein the coil drive module comprises:
a crossover distortion cancellation unit configured to: the first end of the operational amplifier unit is connected with the output end of the operational amplifier unit, and the second end of the operational amplifier unit is connected with the input end of the compensation coil;
a push-pull unit configured to: the first end is connected with the output end of the operational amplifier unit, the second end is connected with the positive power supply, the third end is connected with the negative power supply, and the fourth end is connected with the second end of the crossover distortion canceling unit.
3. The coil drive circuit according to claim 2, wherein the push-pull unit comprises:
a first switching tube configured to: the first end of the cross-over distortion cancellation unit is connected with the second end of the cross-over distortion cancellation unit, the second end of the cross-over distortion cancellation unit is connected with the output end of the operational amplifier unit, and the third end of the cross-over distortion cancellation unit is connected with the positive power supply;
a second switching tube configured to: the first end is connected with the second end of the crossover distortion canceling unit, the second end is connected with the output end of the operational amplifier unit, and the third end is connected with the negative power supply.
4. The coil drive circuit according to claim 3,
when the driving current of the compensation coil is smaller than the preset current, the first switch tube and the second switch tube are both closed, and the driving alternating-current voltage signal is transmitted to the compensation coil through the crossover distortion cancelling unit.
5. The coil drive circuit according to claim 3,
when the driving current of the compensation coil is larger than or equal to the preset current and the amplitude of the driving alternating voltage signal is in the positive half cycle, the first switch tube is switched on, and the second switch tube is switched off.
6. The coil drive circuit according to claim 3,
when the driving current of the compensation coil is larger than or equal to the preset current and the amplitude of the driving alternating voltage signal is in the negative half cycle, the first switch tube is closed and conducted, and the second switch tube is conducted.
7. The coil driving circuit according to any one of claims 3-6, wherein the first switching tube comprises an NPN transistor, and the second switching tube comprises a PNP transistor.
8. The coil drive circuit according to any one of claims 3 to 6, wherein the crossover distortion canceling unit includes an adjustable resistance.
9. The coil drive circuit according to any of claims 3 to 6, wherein the operational amplifier unit comprises an operational amplifier.
10. A current sensor comprising a coil drive circuit according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222006059.4U CN218003525U (en) | 2022-08-01 | 2022-08-01 | Coil drive circuit and current sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222006059.4U CN218003525U (en) | 2022-08-01 | 2022-08-01 | Coil drive circuit and current sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218003525U true CN218003525U (en) | 2022-12-09 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202222006059.4U Active CN218003525U (en) | 2022-08-01 | 2022-08-01 | Coil drive circuit and current sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN218003525U (en) |
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2022
- 2022-08-01 CN CN202222006059.4U patent/CN218003525U/en active Active
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