CN109085410B - Self-excitation type closed-loop fluxgate current sensor circuit - Google Patents
Self-excitation type closed-loop fluxgate current sensor circuit Download PDFInfo
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Abstract
The invention provides a self-excitation type closed-loop fluxgate current sensor circuit, which comprises: the positive power supply, the first H-bridge switching tube, the second H-bridge switching tube, the third H-bridge switching tube, the fourth H-bridge switching tube and the magnetic field detection coil; the magnetic field detection device comprises a current limiting resistor, a magnetic field detection coil current sampling resistor, an integral filter circuit and a compensation coil; the voltage on the current sampling resistor of the magnetic field detection coil is the input quantity of the integration filter circuit, the compensation coil is connected to the output loop of the integration filter circuit, and the compensation coil outputs the current of the integration filter circuit. The self-excitation type closed-loop fluxgate current sensor circuit is a closed-loop circuit which is used for detecting the current average value of a magnetic field detection coil, outputting a compensation current finally through filtering integration of the current and enabling a magnetic core to be in a zero-magnetic-flux state; the invention discloses a closed-loop fluxgate control circuit different from an integrated fluxgate control chip, which is simple and practical, low in cost and comparable to the integrated fluxgate control chip in performance.
Description
Technical Field
The invention belongs to the technical field of current isolation detection and sensing, and particularly relates to a self-excitation type closed-loop fluxgate current sensor circuit.
Technical Field
The fluxgate sensor measures the weak magnetic field by utilizing the nonlinear relation between the magnetic induction intensity and the magnetic field intensity of a high-permeability magnetic core in the magnetic field to be measured under the saturated excitation of an alternating magnetic field. This physical phenomenon appears to the measured ambient magnetic field as a "gate" through which the corresponding magnetic flux is modulated and induced electromotive force is generated. The magnetic field generated by the current is measured by utilizing the phenomenon, so that the purpose of measuring the current is indirectly achieved.
The fluxgate current sensor has the advantages of quick response time (less than 1 us), good temperature characteristic (less than 100 PPM), high sensitivity (uA level), capability of measuring direct current and alternating current simultaneously, wide measuring range (mA level-several kA levels), and important position in the field of high-performance current measurement. Most of the current fluxgate current sensor products are designed based on an integrated fluxgate control chip, the price is high, and domestic sensor manufacturers basically have no similar products (mainly magnetic materials and technical reasons).
Disclosure of Invention
The invention aims to provide a simple, practical, low-cost and high-performance closed-loop fluxgate current sensor control circuit.
The invention provides a self-excitation type closed-loop fluxgate current sensor circuit, which comprises: the positive power supply, the first H-bridge switching tube, the second H-bridge switching tube, the third H-bridge switching tube, the fourth H-bridge switching tube and the magnetic field detection coil; the magnetic field detection device comprises a current limiting resistor, a magnetic field detection coil current sampling resistor, an integral filter circuit and a compensation coil; wherein the magnetic field detection coil is a saturable inductor; the first H bridge switching tube, the second H bridge switching tube, the third H bridge switching tube, the fourth H bridge switching tube, the magnetic field detection coil and the current limiting resistor form a self-oscillation circuit; the source electrode of the first H-bridge switching tube is connected with the source electrode of the second H-bridge switching tube and both are connected with a positive power supply; the source electrode of the third H-bridge switching tube is connected with the source electrode of the fourth H-bridge switching tube and is connected to a reference zero point or a negative power supply through a current limiting resistor; the drain electrode of the first H-bridge switching tube is connected with the drain electrode of the third H-bridge switching tube at a first connecting point, the drain electrode of the second H-bridge switching tube is connected with the drain electrode of the fourth H-bridge switching tube at a second connecting point, and the magnetic field detection coil current sampling resistor are connected in series between the first connecting point and the second connecting point; the grid electrode of the first H-bridge switching tube and the grid electrode of the third H-bridge switching tube are connected together and are communicated with the second connection point; the grid electrode of the second H-bridge switching tube is connected with the grid electrode of the fourth H-bridge switching tube and communicated with the first connecting point; the voltage on the current sampling resistor of the magnetic field detection coil is the input quantity of the integration filter circuit, the compensation coil is connected to the output loop of the integration filter circuit, and the compensation coil outputs the current of the integration filter circuit.
Further, the integrating filter circuit comprises an operational amplifier, an integrating resistor and an integrating capacitor, wherein the integrating resistor is connected in series between the magnetic field detection coil and the reverse input end of the operational amplifier, the integrating capacitor is connected in series between the reverse input end of the operational amplifier and the output end of the operational amplifier, and the forward input end of the operational amplifier is connected with the magnetic field detection coil current sampling resistor.
Further, the first H-bridge switching tube and the second H-bridge switching tube are P-type MOS tubes, and the third H-bridge switching tube and the fourth H-bridge switching tube are N-type MOS tubes.
Further, a first circuit is also included, the first circuit including a first oscillating resistor and a second oscillating resistor, wherein the first oscillating resistor is connected in series between the positive power supply and the second connection point, and the second oscillating resistor is connected in series between the positive power supply VCC2 and the first connection point.
Further, the magnetic field detection coil current sampling circuit comprises a second circuit, the second circuit comprises an integral filter circuit in-phase input fourth input resistor and a second filter capacitor, wherein the fourth input resistor is connected in series between the magnetic field detection coil current sampling resistor and the positive input end of the operational amplifier, and the second filter capacitor is connected to a reference zero point or a negative power supply through the positive input end of the operational amplifier.
Further, the circuit comprises a third circuit, the third circuit is a current amplifying circuit, the current amplifying circuit comprises a seventh input resistor, a fifth triode and a sixth triode, one end of the seventh input resistor is connected with the output end of the operational amplifier, the base electrode of the fifth triode is connected with the base electrode of the sixth triode and then is connected with the other end of the seventh input resistor, the emitter of the fifth triode is connected with the emitter of the sixth triode, the collector of the fifth triode is connected with a positive power supply, and the collector of the sixth triode is connected with a reference zero point or a negative power supply.
Further, the fifth triode is an NPN triode, and the sixth triode is a PNP triode.
Further, the circuit comprises a fourth circuit, the fourth circuit comprises a first free-wheeling diode and a second free-wheeling diode, wherein the cathode of the first free-wheeling diode is connected with a positive power supply, the anode of the first free-wheeling diode is connected with the cathode of the second free-wheeling diode, and the anode of the second free-wheeling diode is connected with a reference zero point or a negative power supply.
The positive power supply is a second positive power supply, and further comprises a fifth circuit and a first positive power supply, wherein the fifth circuit is a voltage-reducing and voltage-stabilizing circuit, and the voltage-reducing and voltage-stabilizing current comprises an eighth input resistor, a voltage-stabilizing diode, a seventh triode and a third filter capacitor; the emitter of the seventh triode is connected with the second positive power supply, the collector of the seventh triode is connected with the first positive power supply, the eighth input resistor is connected in series between the first positive power supply and the base of the seventh triode, one end of the third filter capacitor is connected with the second positive power supply, the other end of the third filter circuit is connected with the reference zero point or the negative power supply, the negative electrode of the voltage stabilizing diode is connected with the base of the seventh triode, and the positive electrode of the voltage stabilizing diode is connected with the reference zero point or the negative power supply.
Further, the seventh triode is an NPN triode.
The self-excitation type closed-loop fluxgate current sensor circuit is a closed-loop circuit which is based on the detection of the current average value of the magnetic field detection coil, outputs a compensation current finally through the filtering integration of the current, and enables the magnetic core to be in a zero-magnetic-flux state, and the self-excitation type closed-loop fluxgate current sensor circuit is simple and practical, good in performance, low in cost and good in consistency; the invention discloses a closed-loop fluxgate control circuit different from an integrated fluxgate control chip, which is simple and practical, low in cost and comparable to the integrated fluxgate control chip in performance.
Drawings
The invention will be further described in the following description of preferred embodiments in a clear and understandable manner, with reference to the accompanying drawings.
FIG. 1 is a circuit diagram of a first embodiment of a self-excited closed loop fluxgate current sensor circuit of the present invention;
fig. 2 is a circuit diagram of a second embodiment of the self-excited closed loop fluxgate current sensor circuit of the present invention.
Detailed Description
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will explain the specific embodiments of the present invention with reference to the accompanying drawings. It is evident that the drawings in the following description are only examples of the invention, from which other drawings and other embodiments can be obtained by a person skilled in the art without inventive effort.
For the sake of simplicity of the drawing, the parts relevant to the present invention are shown only schematically in the figures, which do not represent the actual structure thereof as a product. Additionally, in order to simplify the drawing for ease of understanding, components having the same structure or function in some of the drawings are shown schematically with only one of them, or only one of them is labeled. Herein, "a" means not only "only this one" but also "more than one" case.
The technical scheme of the invention is described in detail in the following by specific embodiments.
The invention discloses a self-excitation type closed-loop fluxgate current sensor circuit, which is actually a closed-loop fluxgate current sensor circuit based on self-excitation oscillation type of a magnetic field detection coil (also called a magnetic probe coil) and average value detection of coil current.
The invention can realize DC or AC current isolation detection based on the magnetic gate and magnetic balance principle.
As shown in fig. 1, which is a circuit diagram of a first embodiment of the self-excited closed-loop fluxgate current sensor circuit of the present invention, the self-excited closed-loop fluxgate current sensor circuit may be powered by a dual power supply or a single power supply, and the self-excited closed-loop fluxgate current sensor circuit includes: a positive power supply VCC (the power supply VCC is a double power supply or a single power supply), a first H-bridge switching tube Q1, a second H-bridge switching tube Q2, a third H-bridge switching tube Q3, a fourth H-bridge switching tube Q4 and a magnetic field detection coil LS; the current limiting resistor R1, the magnetic field detection coil current sampling resistor R2, the integration filter circuit and the compensation coil W1 connected with the integration filter circuit, wherein the compensation coil W1 outputs the current Iout of the circuit.
The first H-bridge switching tube Q1 and the second H-bridge switching tube Q2 are P-type MOS tubes, and the third H-bridge switching tube Q3 and the fourth H-bridge switching tube Q4 are N-type MOS tubes; the magnetic field detection coil LS is a saturable inductor, and the magnetic material inside the coil is usually made of magnetic materials with high initial permeability and low saturation induction, wherein the saturable inductor means that when the current in the inductor is greater than a certain threshold value, the inductance thereof is rapidly reduced, and the current is rapidly increased, which is indicated as inductance saturation.
The first H-bridge switching tube Q1, the second H-bridge switching tube Q2, the third H-bridge switching tube Q3, the fourth H-bridge switching tube Q4, the magnetic field detection coil LS and the current limiting resistor R1 form a self-oscillation circuit.
In a self-oscillating circuit: the source electrode of the first H-bridge switching tube Q1 and the source electrode of the second H-bridge switching tube Q2 are connected and are both connected with a positive power supply VCC; the source electrode of the third H-bridge switching tube Q3 and the source electrode of the fourth H-bridge switching tube Q4 are connected and are connected to a reference zero point or a negative power supply through a current limiting resistor R1; the drain of the first H-bridge switching tube Q1 is connected with the drain of the third H-bridge switching tube Q3 (the connection point is the point a shown in fig. 1, i.e., the first connection point), the drain of the second H-bridge switching tube Q2 is connected with the drain of the fourth H-bridge switching tube Q4 (the connection point is the point B shown in fig. 1, i.e., the second connection point), the magnetic field detection coil LS and the magnetic field detection coil current sampling resistor R2 are connected in series between the connection point of the drain of the first H-bridge switching tube Q1 and the drain of the third H-bridge switching tube Q3 and the connection point of the drain of the second H-bridge switching tube Q2 and the drain of the fourth H-bridge switching tube Q4 (i.e., the magnetic field detection coil LS and the magnetic field detection coil current sampling resistor R2 are connected in series between the point a and the point B); the grid electrode of the first H-bridge switching tube Q1 and the grid electrode of the third H-bridge switching tube Q3 are connected together and communicated with the point B (can be directly communicated or can be communicated through a resistor); the grid electrode of the second H-bridge switching tube Q2 and the grid electrode of the fourth H-bridge switching tube Q4 are connected together and communicated with each other at the point A (can be directly communicated or can be communicated through a resistor).
The integrating filter circuit comprises an operational amplifier U1, an integrating resistor R3 and an integrating capacitor C1, wherein the integrating resistor R3 is connected in series between the magnetic field detection coil LS and the reverse input end of the operational amplifier U1, the integrating capacitor C1 is connected in series between the reverse input end of the operational amplifier and the output end of the operational amplifier U1, and the forward input end of the operational amplifier U1 is connected with the magnetic field detection coil current sampling resistor R2.
The voltage on the current sampling resistor R2 of the magnetic field detection coil is the input quantity of the integrating filter circuit, and the compensation coil W1 is connected to the output loop of the integrating filter circuit (namely, the compensation coil W1 is connected with the output end of the operational amplifier U1, including direct connection or connection through a current amplifying circuit diagram).
As shown in fig. 2, which is a circuit diagram of a second embodiment of the self-excited closed-loop fluxgate current sensor circuit of the present invention, compared with the first embodiment, the self-excited closed-loop fluxgate current sensor circuit adopts a dual power supply (i.e., a first positive power supply VCC1 and a second positive power supply VCC 2) or a single power supply, and the self-excited closed-loop fluxgate current sensor circuit further comprises one circuit or a plurality of circuits or all five circuits, one circuit or a plurality of circuits or all five circuits being added in the circuit shown in fig. 1.
The five circuits are a first circuit, a second circuit, a third circuit, a fourth circuit and a fifth circuit respectively.
The first circuit comprises a first oscillation starting resistor R5 and a second oscillation starting resistor R6, wherein the first oscillation starting resistor R5 is connected between the second positive power supply VCC2 and the point B in series, and the second oscillation starting resistor R6 is connected between the second positive power supply VCC2 and the point A in series.
The second circuit comprises an integral filter circuit in-phase input fourth input resistor R4 and a second filter capacitor C2, wherein the fourth input resistor R4 is connected in series between the magnetic field detection coil current sampling resistor R2 and the positive input end of the operational amplifier U1, and the second filter capacitor C2 is connected to a reference zero point or a negative power supply through the positive input end of the operational amplifier U1.
The third circuit is a current amplifying circuit, and the current amplifying circuit comprises a seventh input resistor R7, a fifth triode Q5 and a sixth triode Q6, wherein the fifth triode Q5 is an NPN triode, the sixth triode Q6 is a PNP triode, and the fifth triode Q5 and the sixth triode Q6 all work in an on-line area.
One end of a seventh input resistor R7 is connected with the output end of the operational amplifier U1, the base electrode of a fifth triode Q5 is connected with the base electrode of a sixth triode Q6 and then is connected with the other end of the seventh input resistor R7, the emitting electrode of the fifth triode Q5 is connected with the emitting electrode of the sixth triode Q6, the collecting electrode of the fifth triode Q5 is connected with the first positive power supply VCC1, and the collecting electrode of the sixth triode Q6 is connected with a reference zero point or a negative power supply.
The fourth circuit comprises a first freewheel diode D1 and a second freewheel diode D2, wherein the cathode of the first freewheel diode D1 is connected with the first positive power supply VCC1, the anode of the first freewheel diode D1 is connected with the cathode of the second freewheel diode D2, and the anode of the second freewheel diode D2 is connected with the reference zero point or the negative power supply.
The fifth circuit is a buck voltage stabilizing circuit, and the buck voltage stabilizing current comprises an eighth input resistor R8, a voltage stabilizing diode Z1, a seventh triode Q7 and a third filter capacitor C3. The seventh triode Q7 is an NPN triode, and the seventh triode Q7 works in an on-line area.
An emitter of the seventh triode Q7 is connected with the second positive power supply VCC2, a collector of the seventh triode Q7 is connected with the first positive power supply VCC1, an eighth input resistor R8 is connected between the first positive power supply VCC1 and a base of the seventh triode Q7 in series, one end of a third filter capacitor C3 is connected with the second positive power supply VCC2, the other end of the third filter circuit C3 is connected with a reference zero point or a negative power supply, a negative electrode of a voltage stabilizing diode Z1 is connected with the base of the seventh triode Q7, and a positive electrode of the voltage stabilizing diode Z1 is connected with the reference zero point or the negative power supply. Self-oscillation of the self-excited closed-loop fluxgate current sensor circuit is accomplished by: when the power is just on, the first H-bridge switching tube Q1, the second H-bridge switching tube Q2, the third H-bridge switching tube Q3 and the fourth H-bridge switching tube Q4 will tend to cause one of the switching tubes to be turned on preferentially due to the incomplete consistency of the device parameters (the first oscillating resistor R5 and the second oscillating resistor R6 introduced in fig. 2 will accelerate the turn-on process); the assumption here is that the first H-bridge switching tube Q1 is first turned on, the point a is at a high level, the high level of a is added to the gates of the second H-bridge switching tube Q2 and the fourth H-bridge switching tube Q4, so that the second H-bridge switching tube Q2 is turned off and the fourth H-bridge switching tube Q4 is turned on, thereby the point B is at a low level, the low level of the point B acts on the gates of the first H-bridge switching tube Q1 and the third H-bridge switching tube Q3 again, so that the first H-bridge switching tube Q1 is turned on and the third H-bridge switching tube Q3 is turned off, that is, a circuit state in which the point a is at a high level and the point B is at a low level is established at this time; at this time, a high voltage B is applied to the magnetic field detection coil LS and the magnetic field detection coil current sampling resistor R2, and since the magnetic field detection coil LS is an inductance element, the current cannot be suddenly changed, so the voltage on A, B will increase the current on the magnetic field detection coil LS (the current from a to B is defined as positive current at this time), and the current will flow through the current limiting resistor R1, so the voltage on the current limiting resistor R1 will also increase, and the voltage at point B will also increase continuously; when the current on the magnetic field detection coil LS is larger than a certain threshold value, the magnetic field detection coil LS is saturated in inductance, the current of the magnetic field detection coil LS rises rapidly, the voltage on the current limiting resistor R1 and the voltage at the point B rise rapidly, when the voltage at the point B is larger than a certain threshold value, the third H-bridge switching tube Q3 is conducted, the first H-bridge switching tube Q1 is turned off, the point A is in a low level, the low voltage acts on the grid electrodes of the second H-bridge switching tube Q2 and the fourth H-bridge switching tube Q4, the second H-bridge switching tube Q2 is conducted, the fourth H-bridge switching tube Q4 is turned off, the point B is in a high level, namely a circuit state that A is in a low level and B is in a high level is established at the moment; at this time, a low voltage B is applied to the magnetic field detection coil LS and the magnetic field detection coil current sampling resistor R2, and since LS is an inductive element, the current cannot be suddenly changed, so the voltage on B, A will increase the current on the magnetic field detection coil LS in the opposite direction (the current from B to a is defined as negative current at this time), and the current will flow through the current limiting resistor R1, so the voltage on the current limiting resistor R1 will also increase, and the voltage at point a will also increase continuously; when the current on the magnetic field detection coil LS is larger than a certain threshold value, the magnetic field detection coil LS is saturated in inductance, the current of the magnetic field detection coil LS rises rapidly, the voltage on the current limiting resistor R1 and the voltage at the point A rise rapidly, when the voltage at the point A is larger than a certain threshold value, the fourth H-bridge switching tube Q4 is conducted, the second H-bridge switching tube Q2 is turned off, the point B is in a low level, the low voltage acts on the grids of the first H-bridge switching tube Q1 and the third H-bridge switching tube Q3, the first H-bridge switching tube Q1 is conducted, the third H-bridge switching tube Q3 is turned off, the point A is in a high level, namely a circuit state that A is in a high level and B is in a low level is established at the moment; the frequency of the repeated oscillation is related to the power supply voltage, the inductance of the magnetic field detection coil LS, the current limiting resistor R1, and the magnetic field detection coil current sampling resistor R2.
The magnetic field detection coil LS is operated in a positive and negative magnetic field saturated state (called a fluxgate) by selecting proper magnetic materials and winding proper turns and designing proper parameters of a current limiting resistor R1 and a magnetic field detection coil current sampling resistor R2, and under normal conditions, the fluxgate is in positive and negative symmetry, and under no influence of an external magnetic field, the average value of working current is zero, namely the average value of voltage on the magnetic field detection coil current sampling resistor R2 is zero; because the fluxgate of the invention works with a single power supply (note: the circuit diagram of the invention can work with a double power supply or a single power supply, but the oscillating circuit of the fluxgate works with a single power supply), the symmetry of the fluxgate is not affected by the power supply (the fluxgate works with better symmetry than the double power supply), thereby ensuring that the circuit has extremely high sensitivity and detection precision.
When an external magnetic field is affected (the current sensor is usually a magnetic field of primary current), the positive and negative symmetry of the fluxgate can be broken, at the moment, the working current average value is not zero, namely, the voltage average value on the current sampling resistor R2 of the magnetic field detection coil is not zero, the voltage is amplified by a subsequent filtering and integrating circuit and then is output to the compensation coil W1, the magnetic field direction formed by the current on the compensation coil W1 is opposite to the magnetic field direction of the primary current, and under the steady state condition, the fluxgate is enabled to work in a zero current (average value) state, so that closed loop current detection is formed.
The self-excitation type closed-loop fluxgate current sensor circuit is a closed-loop circuit which is used for detecting the current average value of a magnetic field detection coil, and finally outputting a compensation current through filtering integration of the current, so that the magnetic core is in a zero-flux state. The circuit is simple and practical, has good performance, low cost and good consistency; the invention discloses a closed-loop fluxgate control circuit different from an integrated fluxgate control chip, which is simple and practical, low in cost and comparable to the integrated fluxgate control chip in performance.
It should be noted that the above embodiments can be freely combined as needed. The present invention is not limited to the specific details of the above embodiments, but it should be noted that, within the scope of the technical concept of the present invention, it is possible to make several improvements and modifications within the scope of the technical concept of the present invention, and it is also possible to make various equivalent changes to the technical solution of the present invention, and these improvements, modifications and equivalent changes should be considered as the scope of the present invention.
Claims (6)
1. A self-excited closed loop fluxgate current sensor circuit, comprising: the positive power supply, the first H-bridge switching tube, the second H-bridge switching tube, the third H-bridge switching tube, the fourth H-bridge switching tube and the magnetic field detection coil; the magnetic field detection device comprises a current limiting resistor, a magnetic field detection coil current sampling resistor, an integral filter circuit and a compensation coil; wherein the magnetic field detection coil is a saturable inductor; the first H bridge switching tube, the second H bridge switching tube, the third H bridge switching tube, the fourth H bridge switching tube, the magnetic field detection coil and the current limiting resistor form a self-oscillation circuit; the source electrode of the first H-bridge switching tube is connected with the source electrode of the second H-bridge switching tube and both are connected with a positive power supply; the source electrode of the third H-bridge switching tube is connected with the source electrode of the fourth H-bridge switching tube and is connected to a reference zero point or a negative power supply through a current limiting resistor; the drain electrode of the first H-bridge switching tube is connected with the drain electrode of the third H-bridge switching tube at a first connecting point, the drain electrode of the second H-bridge switching tube is connected with the drain electrode of the fourth H-bridge switching tube at a second connecting point, and the magnetic field detection coil current sampling resistor are connected in series between the first connecting point and the second connecting point; the grid electrode of the first H-bridge switching tube and the grid electrode of the third H-bridge switching tube are connected together and are communicated with the second connection point; the grid electrode of the second H-bridge switching tube is connected with the grid electrode of the fourth H-bridge switching tube and communicated with the first connecting point; the voltage on the current sampling resistor of the magnetic field detection coil is the input quantity of the integration filter circuit, the compensation coil is connected to the output loop of the integration filter circuit, and the compensation coil outputs the current of the integration filter circuit; the first H bridge switching tube and the second H bridge switching tube are P-type MOS tubes, and the third H bridge switching tube and the fourth H bridge switching tube are N-type MOS tubes; the integral filter circuit comprises an operational amplifier, an integral resistor and an integral capacitor, wherein the integral resistor is connected in series between the magnetic field detection coil and the reverse input end of the operational amplifier, the integral capacitor is connected in series between the reverse input end of the operational amplifier and the output end of the operational amplifier, and the forward input end of the operational amplifier is connected with the magnetic field detection coil current sampling resistor.
2. The self-excited closed loop fluxgate current sensor circuit of claim 1, wherein: the circuit further comprises a first circuit, wherein the first circuit comprises a first oscillating resistor and a second oscillating resistor, the first oscillating resistor is connected between the positive power supply and the second connecting point in series, and the second oscillating resistor is connected between the positive power supply VCC2 and the first connecting point in series.
3. The self-excited closed loop fluxgate current sensor circuit of claim 1, wherein: the second circuit comprises an integral filter circuit, wherein the integral filter circuit is in-phase input with a fourth input resistor and a second filter capacitor, the fourth input resistor is connected in series between the magnetic field detection coil current sampling resistor and the positive input end of the operational amplifier, and the second filter capacitor is connected to a reference zero point or a negative power supply through the positive input end of the operational amplifier.
4. The self-excited closed loop fluxgate current sensor circuit of claim 1, wherein: the third circuit is a current amplifying circuit, the current amplifying circuit comprises a seventh input resistor, a fifth triode and a sixth triode, one end of the seventh input resistor is connected with the output end of the operational amplifier, the base electrode of the fifth triode is connected with the base electrode of the sixth triode and then is connected with the other end of the seventh input resistor, the emitter electrode of the fifth triode is connected with the emitter electrode of the sixth triode, the collector electrode of the fifth triode is connected with a positive power supply, and the collector electrode of the sixth triode is connected with a reference zero point or a negative power supply; the fifth triode is an NPN triode, and the sixth triode is a PNP triode.
5. The self-excited closed loop fluxgate current sensor circuit of claim 1, wherein: the circuit comprises a first flywheel diode, a second flywheel diode, a first power supply, a second power supply, a third circuit, a fourth circuit and a reference zero point or a negative power supply, wherein the negative electrode of the first flywheel diode is connected with the positive power supply, the positive electrode of the first flywheel diode is connected with the negative electrode of the second flywheel diode, and the positive electrode of the second flywheel diode is connected with the reference zero point or the negative power supply.
6. The self-excited closed loop fluxgate current sensor circuit of claim 1, wherein: the positive power supply is a second positive power supply, and further comprises a fifth circuit and a first positive power supply, wherein the fifth circuit is a voltage-reducing and voltage-stabilizing circuit, and the voltage-reducing and voltage-stabilizing current comprises an eighth input resistor, a voltage-stabilizing diode, a seventh triode and a third filter capacitor; the emitter of the seventh triode is connected with the second positive power supply, the collector of the seventh triode is connected with the first positive power supply, the eighth input resistor is connected in series between the first positive power supply and the base of the seventh triode, one end of the third filter capacitor is connected with the second positive power supply, the other end of the third filter circuit is connected with a reference zero point or a negative power supply, the negative electrode of the voltage stabilizing diode is connected with the base of the seventh triode, and the positive electrode of the voltage stabilizing diode is connected with the reference zero point or the negative power supply; the seventh triode is an NPN triode.
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| CN113466530A (en) * | 2020-03-31 | 2021-10-01 | 比亚迪半导体股份有限公司 | Current sensor |
| CN111880129B (en) * | 2020-07-24 | 2021-12-07 | 吉林大学 | Self-adaptive compensation fluxgate sensor |
| CN111913028A (en) * | 2020-08-18 | 2020-11-10 | 宁波中车时代传感技术有限公司 | Fluxgate current sensor based on chip type coil |
| CN112198362A (en) * | 2020-10-30 | 2021-01-08 | 常州常荣传感技术有限公司 | Drive circuit for closed-loop current sensor |
| CN114414878B (en) * | 2022-01-25 | 2022-09-27 | 深圳市艾华迪技术有限公司 | Double-excitation automatic desaturation closed loop fluxgate current sensor circuit |
| CN116754823B (en) * | 2023-06-19 | 2024-02-02 | 深圳柯力三电科技有限公司 | Control method of fluxgate vibration |
| CN116539949A (en) * | 2023-07-04 | 2023-08-04 | 杰华特微电子股份有限公司 | Current detection device, detection method and switching circuit of H-bridge circuit |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60173475A (en) * | 1984-02-20 | 1985-09-06 | Mishima Kosan Co Ltd | Self-oscillation type current sensor |
| CN104568033A (en) * | 2014-12-31 | 2015-04-29 | 重庆川仪自动化股份有限公司 | High-frequency excitation device |
| CN105652140A (en) * | 2016-01-22 | 2016-06-08 | 深圳市艾华迪技术有限公司 | Leakage current detection circuit |
| CN205484631U (en) * | 2016-01-22 | 2016-08-17 | 深圳市艾华迪技术有限公司 | Leakage current detection circuit |
| CN206258144U (en) * | 2016-12-20 | 2017-06-16 | 刘超越 | A kind of field circuit for adapting to different impedance transducer internal resistances |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI222266B (en) * | 2002-02-14 | 2004-10-11 | Kazuo Kohno | Self oscillation circuits |
| US8624684B2 (en) * | 2011-04-22 | 2014-01-07 | Continental Automotive Systems, Inc | Adaptive current limit oscillator starter |
| CN209086314U (en) * | 2018-10-24 | 2019-07-09 | 深圳市艾华迪技术有限公司 | A kind of self-excitation type closed-loop fluxgate current sensor circuit |
-
2018
- 2018-10-24 CN CN201811244475.XA patent/CN109085410B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60173475A (en) * | 1984-02-20 | 1985-09-06 | Mishima Kosan Co Ltd | Self-oscillation type current sensor |
| CN104568033A (en) * | 2014-12-31 | 2015-04-29 | 重庆川仪自动化股份有限公司 | High-frequency excitation device |
| CN105652140A (en) * | 2016-01-22 | 2016-06-08 | 深圳市艾华迪技术有限公司 | Leakage current detection circuit |
| CN205484631U (en) * | 2016-01-22 | 2016-08-17 | 深圳市艾华迪技术有限公司 | Leakage current detection circuit |
| CN206258144U (en) * | 2016-12-20 | 2017-06-16 | 刘超越 | A kind of field circuit for adapting to different impedance transducer internal resistances |
Non-Patent Citations (1)
| Title |
|---|
| Self-Oscillating Fluxgate-Based Quasi-Digital Sensor for DC High-Current Measurement;Nong Wang 等;《IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT》;第64卷(第12期);3555-3563 * |
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