CN110687339A - Current sensor - Google Patents
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- CN110687339A CN110687339A CN201910514547.6A CN201910514547A CN110687339A CN 110687339 A CN110687339 A CN 110687339A CN 201910514547 A CN201910514547 A CN 201910514547A CN 110687339 A CN110687339 A CN 110687339A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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Abstract
The invention provides a current sensor capable of improving the measurement accuracy of current. A current sensor (1) is provided with: a magnetic core (10) that can be disposed around the axial direction of a wire (2) through which a current to be measured flows; an excitation coil (22) wound around the magnetic core (10); a feedback coil (32) wound around the magnetic core (10) and the exciting coil (22); an excitation circuit (24) that inputs an excitation current to the excitation coil (22); a detection circuit (40) that detects a signal corresponding to the current to be measured based on the output of the excitation coil (22); a feedback circuit (34) that outputs a feedback signal based on a signal corresponding to the current to be measured to a feedback coil (32); an integration amplifier circuit (50) that integrates the output of the excitation coil (22) and outputs the result amplified by a predetermined magnification as a cancellation signal; and an arithmetic circuit (60) that subtracts the cancellation signal from a signal based on the feedback coil current flowing through the feedback coil (32).
Description
Cross-reference to related applications
The present application claims priority from japanese patent application No. 2018-128109 (application No. 7/5/2018), and the disclosure of this application is incorporated herein by reference in its entirety.
Technical Field
The present disclosure relates to current sensors.
Background
Conventionally, a Zero Flux (Zero Flux) type current sensor is known (for example, see patent document 1).
Documents of the prior art
Patent document
Patent document 1: international publication No. 2006/129389
Disclosure of Invention
Problems to be solved by the invention
In the zero-flux current sensor, the excitation current may cause noise in the feedback coil. The noise may reduce the current measurement accuracy.
An object of the present disclosure is to provide a current sensor capable of improving the accuracy of current measurement.
Means for solving the problems
The current sensor according to some embodiments includes a magnetic core, an exciting coil, a feedback coil, an exciting circuit, a detecting circuit, a feedback circuit, an integrating and amplifying circuit, and an arithmetic circuit. The magnetic core may be disposed around an axial direction of a wire through which a current to be measured flows. The excitation coil is wound around the magnetic core. The feedback coil is wound around the magnetic core and an outer side of the exciting coil. The excitation circuit inputs excitation current to the excitation coil. The detector circuit detects a signal corresponding to the current to be measured based on an output of the exciting coil. The feedback circuit outputs a feedback signal based on a signal corresponding to the current to be measured to the feedback coil. The integration amplifier circuit integrates the output of the exciting coil and outputs the result amplified by a predetermined magnification as a cancel signal. An arithmetic circuit subtracts the cancellation signal from a signal based on a feedback coil current flowing through the feedback coil. In this way, noise due to the exciting current included in the feedback coil current is cancelled, and the measurement accuracy of the current sensor is improved. Further, the measurement accuracy is improved by a relatively inexpensive and small configuration.
In the current sensor of an embodiment, the feedback circuit may flow a feedback current to the feedback coil as the feedback signal. Thus, the measurement accuracy of the current sensor is improved. Further, the measurement accuracy is improved by a relatively inexpensive and small configuration.
In the current sensor of an embodiment, the magnetic core may be openable and closable. Thus, the current sensor can be easily attached to the lead wire because the magnetic core can be opened and closed. As a result, the convenience of the current sensor is improved.
In the current sensor according to an embodiment, the integrating and amplifying circuit may determine the predetermined magnification based on the feedback coil current and an output of the exciting coil. Thus, the cancellation signal efficiently approaches the noise due to the excitation signal. As a result of the cancellation signal approaching the noise due to the excitation signal, the measurement accuracy of the current sensor improves.
Effects of the invention
According to the present disclosure, a current sensor capable of improving the accuracy of current measurement is provided.
Drawings
Fig. 1 is a block diagram showing a configuration example of a current sensor according to an embodiment.
Fig. 2 is a plan view showing a configuration example of the magnetic sensor.
Fig. 3 is a sectional view a-a of fig. 2.
Fig. 4 is a plan view showing an example of a magnetic sensor to which a magnetic core having a contact portion is attached.
Fig. 5 is a plan view showing a state where the contact portion of the magnetic core of fig. 4 is opened.
Fig. 6 is a block diagram showing the structure of the current sensor of comparative example 1.
Fig. 7 is a sectional view showing the structure of the current sensor of comparative example 2.
Description of reference numerals:
1 Current sensor
2 conducting wire
10 magnetic core
12 magnetic collector
14 contact part
16 deformation part
20 magnetic sensor
22 field coil
24 exciting circuit
32 feedback coil
34 feedback circuit
40 wave detection circuit
50 integral amplifying circuit
60 arithmetic circuit
70 output part
Detailed Description
Conventionally, there is known a sensor that detects a magnetic flux generated by a current to be measured by a core surrounding the current to be measured and a coil wound around the core. The sensor measures a current to be measured based on a result of the excitation of the core by the coil, or measures a current to be measured based on a current induced in the coil by the current to be measured.
When the core is excited to measure the current to be measured, the measurement result may contain noise due to the excitation. In the case where two cores excited in opposite directions are provided to cancel out noise caused by excitation, an increase in cost and an increase in size of the sensor are caused.
On the other hand, as shown in fig. 1, the current sensor 1 according to one embodiment of the present disclosure includes a magnetic sensor 20, an exciting circuit 24, a feedback circuit 34, a detector circuit 40, an integrating/amplifying circuit 50, and an arithmetic circuit 60. The magnetic sensor 20 has a magnetic core 10, an exciting coil 22, and a feedback coil 32. The current sensor 1 may further have an output section 70. As described later, the current sensor 1 includes the integrating and amplifying circuit 50 and the arithmetic circuit 60, and thus can cancel noise due to excitation. The integrating amplifier circuit 50 and the operational circuit 60 may be formed of relatively inexpensive components such as a filter and an operational amplifier. That is, the current sensor 1 according to the embodiment of the present disclosure can improve the measurement accuracy of the current to be measured while reducing the cost and size.
As shown in fig. 2 and 3, the magnetic core 10 is located around the axial direction of the wire 2 extending in the Z-axis direction. That is, the magnetic core 10 can be disposed around the axial direction of the wire 2. The Z-axis is represented in a positive direction from the inner side of the paper surface to the front side of the paper surface. The X-axis and the Y-axis are represented as axes extending along the paper plane in a manner orthogonal to the Z-axis. The magnetic core 10 forms a closed magnetic path around the axial direction of the wire 2. The current flowing in the wire 2 generates a magnetic flux around the axial direction of the wire 2. At least a portion of the magnetic beam passes through the closed magnetic circuit formed by the magnetic core 10. The current sensor 1 can measure the magnitude of the current flowing through the lead wire 2 by detecting the magnetic flux passing through the core 10 by the magnetic sensor 20. The current flowing through the conductor 2 is also referred to as measured current. The magnetic core 10 forms a closed magnetic path around the axial direction of the wire 2, so that magnetic flux generated by the current to be measured easily passes through the magnetic core 10 and is easily detected by the current sensor 1. As a result, the measurement accuracy of the current to be measured is improved.
The current sensor 1 may further have a magnetic concentrator 12 that concentrates the magnetic flux to the magnetic core 10. Magnetic collector 12 may have an outer magnetic collector 12a and an inner magnetic collector 12 b. The magnetic core 10 may be located between the outer magnetic collector 12a and the inner magnetic collector 12 b. Since the magnetic flux is concentrated on the magnetic core 10, the current sensor 1 can more easily detect the magnetic flux generated by the current to be measured.
The magnetic core 10 may contain a soft magnetic material such as iron or ferrite. The shape of the magnetic core 10 may be a ring shape. The closed magnetic path formed by the magnetic core 10 may be in a shape of a circle or a shape close to a circle in a plan view. When the region surrounded by the closed magnetic path has a shape of a circle or a shape close to a circle in a plan view, the size of a magnetic flux generated in the closed magnetic path by a current flowing through the conductor 2 intersecting the region is less likely to change regardless of the position where the conductor 2 intersects the region. As a result, the measurement accuracy of the current to be measured is improved.
The exciting coil 22 is wound around the magnetic core 10. In the case where the magnetic collector 12 is provided, the exciting coil 22 may be wound around the inner side of the magnetic collector 12. The excitation coil 22 may be wound over the entire closed magnetic circuit formed by the magnetic core 10, or may be wound around a part of the closed magnetic circuit. The excitation coil 22 may be constituted by one coil or may be divided into a plurality of coils. In the case where the excitation coil 22 is divided into a plurality of coils, the coils may be connected in series. In the case where the exciting coil 22 is divided into a plurality of coils, the number of turns of the exciting coil 22 may be the sum of the number of turns of the respective coils.
The feedback coil 32 is wound further outside the exciting coil 22. In the case where the magnetic collector 12 is provided, the feedback coil 32 may be wound outside the magnetic collector 12. The winding direction of the exciting coil 22 and the winding direction of the feedback coil 32 may be the same direction or opposite directions. The feedback coil 32 may be wound over the entire closed magnetic circuit formed by the magnetic core 10, or may be wound around a part of the closed magnetic circuit. The feedback coil 32 may be constituted by one coil or may be divided into a plurality of coils. In the case where the feedback coil 32 is divided into a plurality of coils, the coils may be connected in series. In the case where the feedback coil 32 is divided into a plurality of coils, the number of turns of the feedback coil 32 may be the sum of the number of turns of the respective coils.
The excitation coil 22 and the feedback coil 32 may be wound repeatedly along at least a part of the path of the closed magnetic circuit, or may be wound so as not to be repeated along the path of the closed magnetic circuit.
The exciting circuit 24 is connected to a terminal of the exciting coil 22, and applies a voltage to the terminal or inputs a current to the terminal. The terminal voltage of the exciting coil 22 is also referred to as an exciting voltage. The current flowing through the exciting coil 22 is also referred to as an exciting current. The excitation current input from the excitation circuit 24 or the excitation voltage applied from the excitation circuit 24 is also referred to as an excitation signal.
When the exciting circuit 24 receives an exciting current from the terminal of the exciting coil 22, the exciting voltage is determined based on a magnetic flux obtained by combining a magnetic flux generated by the input exciting current and a magnetic flux generated by a current to be measured in a closed magnetic path along the magnetic core 10. That is, the excitation voltage appearing in response to the input of the excitation current changes based on the change in the measured current. The current sensor 1 can measure the current to be measured by inputting an excitation current to the excitation coil 22 and measuring an excitation voltage.
When the exciting circuit 24 applies an exciting voltage to both ends of the exciting coil 22, an exciting current flows so that a magnetic flux is generated in which a magnetic flux corresponding to the applied exciting voltage and a magnetic flux generated by a current to be measured are combined. That is, the excitation current flowing in accordance with the application of the excitation voltage changes based on the change in the measured current. The current sensor 1 applies an excitation voltage to the excitation coil 22 and measures an excitation current, thereby measuring a current to be measured.
The detector circuit 40 detects at least one of an excitation current and an excitation voltage from the excitation coil 22 as an output of the excitation coil 22. When the exciting circuit 24 receives an exciting current, the detector circuit 40 detects an exciting voltage as an output of the exciting coil 22. When the exciting circuit 24 applies an exciting voltage, the detector circuit 40 converts the exciting current into a voltage and detects the voltage as an output of the exciting coil 22. For example, the detector circuit 40 may detect a terminal voltage of a resistor through which an exciting current flows as an output of the exciting coil 22.
The output of the exciting coil 22 is determined based on an exciting signal input to the exciting coil 22 and a B-H curve representing hysteresis (hystersis) characteristics of the core 10. The magnetic flux generated in the magnetic core 10 by the current to be measured modulates the change in the magnetic flux generated based on the input of the excitation signal, and changes the output of the excitation coil 22. The output of the exciting coil 22 when the current to be measured does not flow indicates a signal corresponding to the exciting signal. The difference between the output of the exciting coil 22 when the current to be measured flows and the output of the exciting coil 22 when the current to be measured does not flow indicates a signal corresponding to the current to be measured. That is, the output of the exciting coil 22 includes a signal corresponding to the exciting signal and a signal corresponding to the current to be measured.
The detector circuit 40 detects a signal corresponding to the current to be measured based on the output of the exciting coil 22. The signal corresponding to the measured current is also referred to as a detection result. For example, the detector circuit 40 may invert the positive and negative of an input terminal for obtaining the output of the excitation coil 22 by a frequency 2 times the frequency of the excitation signal. The detector circuit 40 may input the acquired output of the excitation coil 22 to an LPF (Low Pass Filter) while inverting the positive and negative of the input terminal at a frequency 2 times the frequency of the excitation signal, and may cut off the high frequency component. The signal thus obtained can be used as a detection result. That is, the detector circuit 40 can calculate the detection result by inverting the positive and negative and cutting the high frequency component when acquiring the output of the exciting coil 22.
When the measured current is zero, the detector circuit 40 may calculate the detection result so that the detection result is zero. The detector circuit 40 may adjust the zero point of the detection result by shifting the detected output of the excitation coil 22 using, for example, a bridge circuit.
The current sensor 1 can calculate the measured current based on the detection result. The method of calculating the measured current based on the detection result is also called a fluxgate (fluxgate) method.
The detector circuit 40 outputs the detection result to the feedback circuit 34.
The feedback circuit 34 is connected to a terminal of the feedback coil 32, and inputs a current to the terminal. The feedback circuit 34 inputs a feedback signal based on the detection result to the feedback coil 32. The feedback signal may be a current or a voltage. The current that the feedback circuit 34 feeds out to the feedback coil 32 as a feedback signal is also referred to as a feedback current. On the other hand, a current based on the measured current is induced in the feedback coil 32. The current induced in the feedback coil 32 by the measured current is also referred to as the induced current. As a result, a current obtained by combining the feedback current and the sense current flows through the feedback coil 32. The current flowing in the feedback coil 32 is also referred to as a feedback coil current. That is, the feedback coil current includes an induced current and a feedback current.
The feedback circuit 34 controls the feedback current so that the magnetic flux generated by the feedback coil current cancels the magnetic flux generated by the current to be measured in the closed magnetic path along the magnetic core 10. For example, in fig. 2, when the measured current flows in the positive direction of the Z axis, magnetic flux based on the current is generated in the closed magnetic path along the magnetic core 10 in the counterclockwise direction when facing the paper surface. In this case, the feedback circuit 34 controls the feedback current so that the magnetic flux based on the feedback coil current is generated toward the clockwise direction when facing the paper face in the closed magnetic path along the magnetic core 10. That is, the feedback circuit 34 controls the feedback current so that the magnetic flux based on the feedback coil current cancels the magnetic flux based on the measured current. In this case, the direction in which the feedback current flows is determined according to the direction in which the feedback coil 32 is wound.
The more high-frequency components contained in the measured current, the more induced current contained in the feedback coil current. On the other hand, the more the dc component or the low-frequency component contained in the measured current, the more the feedback current contained in the feedback coil current.
In the present embodiment, the feedback coil current includes the induced current and the feedback current, and thus the feedback coil current can follow the current to be measured with high accuracy regardless of the frequency component included in the current to be measured. As a result, the current sensor 1 can measure the current to be measured with high accuracy based on the feedback coil current. The method of calculating the measured current based on the feedback coil current is also referred to as a zero-flux method.
The zero-flux system is different from the fluxgate system in that a magnetic flux based on the measured current is canceled by a magnetic flux based on the feedback coil current in the closed magnetic path along the magnetic core 10. Since the magnetic flux based on the measured current is cancelled, the influence of the hysteresis of the magnetic core 10 is reduced when the measured current is calculated by the current sensor 1. As a result, when the zero-flux system is adopted, the linearity of the graph showing the relationship between the measured current and the feedback coil current is improved. Further, since the magnetic flux based on the measured current is cancelled, the influence of the temperature change is reduced when the measured current is calculated by the current sensor 1. As a result, the stability of the calculated value of the measured current is improved. That is, if the zero-flux method is adopted, the measured current can be calculated with higher accuracy.
The detector circuit 40 and the feedback circuit 34 may be included in one circuit.
The feedback coil current also includes a current induced by a magnetic flux generated by the excitation current in the closed magnetic path along the magnetic core 10. That is, the current measured based on the magnitude of the feedback coil current includes noise due to the excitation signal. The noise due to the excitation signal is proportional to the magnetic flux generated in the magnetic core 10 by the excitation current.
The current sensor 1 of the present embodiment further includes the integrating and amplifying circuit 50 and the arithmetic circuit 60, and can cancel out noise due to the excitation signal included in the feedback coil current, thereby improving the measurement accuracy of the current to be measured.
The integrating and amplifying circuit 50 acquires an output of the exciting coil 22. The integrating and amplifying circuit 50 acquires the terminal voltage of the exciting coil 22 as the output of the exciting coil 22. The integration amplifier circuit 50 integrates the output of the exciting coil 22. The signal obtained by integrating the output of the excitation coil 22 is also referred to as an integration result. The integrating and amplifying circuit 50 may have a first-order LPF including a resistor and a capacitor as an integrating circuit.
The voltage of the coil is proportional to a value obtained by time-differentiating the magnetic beam generated by the coil. For the excitation coil 22, for example, the following equations (1) and (2) hold. In the formulae (1) and (2), t represents time. VLRepresenting the terminal voltage of the excitation coil 22. Φ represents a magnetic flux of the excitation coil 22.
Further, the integration result is a signal obtained by integrating the terminal voltage of the exciting coil 22, and is thus proportional to the magnetic flux of the exciting coil 22. That is, the integration result is proportional to the magnetic flux generated in the magnetic core 10 by the excitation current and proportional to the noise contained in the feedback coil current. The integrating and amplifying circuit 50 amplifies the integration result by a predetermined magnification, and outputs a signal obtained as a result to the arithmetic circuit 60. The signal output from the integrating and amplifying circuit 50 to the arithmetic circuit 60 is also referred to as a cancel signal. The cancellation signal is a signal that is the same as or similar to noise contained in the feedback current. The cancellation signal is set to a signal represented by a voltage. The integrating amplification circuit 50 may have a circuit in which an operational amplifier is included as an amplification circuit. The predetermined magnification is determined based on the time constant of the LPF included in the integrating circuit, the number of turns of the exciting coil 22, the number of turns of the feedback coil 32, the self-inductance of the feedback coil 32, or the like.
The predetermined magnification may be determined based on the feedback coil current and the output of the exciting coil 22. The predetermined magnification may be determined based on the waveform of the feedback coil current and the waveform of the voltage of the exciting coil 22. In other words, the integrating and amplifying circuit 50 may determine the predetermined magnification based on the feedback coil current and the output of the exciting coil 22.
The predetermined magnification may be determined based on the feedback coil current and the voltage of the exciting coil 22 when the measured current is zero. The feedback coil current in the case where the measured current is zero contains only a noise component. Since the predetermined magnification is determined under the condition that the measured current is zero, the cancellation signal can be efficiently brought close to the noise caused by the excitation signal.
The predetermined magnification is not limited to the case where the measured current is zero, and may be determined based on the feedback coil current and the voltage of the exciting coil 22 when the measured current is a predetermined value. The predetermined value may be, for example, 1A (ampere) of direct current.
The predetermined magnification may be determined based on the instantaneous data of the feedback coil current and the instantaneous data of the voltage of the exciting coil 22. Since the predetermined magnification is determined based on the instantaneous data, the cancel signal can more efficiently approach the noise caused by the excitation signal.
According to the various methods described above, the measurement accuracy of the current sensor 1 is improved as a result of the cancellation signal approaching the noise caused by the excitation signal.
The arithmetic circuit 60 acquires a signal based on the feedback current from the feedback circuit 34, and acquires a cancellation signal from the integrating-amplifying circuit 50. The signal based on the feedback current is set to a signal represented by a voltage. The arithmetic circuit 60 subtracts the cancellation signal from the signal based on the feedback current, and outputs the subtraction result to the output unit 70. The operation circuit 60 may have a circuit in which an operational amplifier is included as a subtraction operation circuit.
The output unit 70 outputs a measured value of the current to be measured based on the subtraction result of the arithmetic circuit 60. The subtraction result of the arithmetic circuit 60 corresponds to a signal obtained by subtracting the influence of noise due to the excitation signal from the signal based on the feedback current. That is, the influence of noise due to the excitation signal is subtracted from the measurement value output from the output unit 70. As a result, the accuracy of the measured value of the measured current can be improved.
The current sensor 1 performs feedback through the exciting circuit 24 and the feedback circuit 34 so as to cancel magnetic flux generated in the closed magnetic circuit along the magnetic core 10 based on the exciting signal. That is, the exciting circuit 24 and the feedback circuit 34 constitute a feedback system. The current sensor 1 has an integrating and amplifying circuit 50 and an arithmetic circuit 60 outside the feedback system. In this way, the influence of the integrating and amplifying circuit 50 and the arithmetic circuit 60 on the operation of the feedback system is negligible or no. As a result, the current sensor 1 further improves the accuracy of current measurement.
The magnetic core 10 may be openable and closable. As shown in fig. 4 and 5, the magnetic core 10 may have the contact portion 14 and the deformation portion 16. The magnetic core 10 is attached around the lead wire 2 in a state where the contact portion 14 is opened, and then constitutes a closed magnetic path around the axial direction of the lead wire 2 in a state where the contact portion 14 is closed. The deformable portion 16 may have an opening/closing structure such as a hinge, or may have flexibility. Since the magnetic core 10 can be opened and closed, the magnetic sensor 20 is easily attached to the lead wire 2. As a result, the convenience of the current sensor 1 is improved.
The current sensor 91 of the comparative example 1 shown in fig. 6 does not include the integrating and amplifying circuit 50 and the arithmetic circuit 60, as compared with the current sensor 1 shown in fig. 1. In the current sensor 91 of comparative example 1, the output unit 70 calculates the current to be measured based on the feedback current and outputs the current as the measurement result of the current. In the measurement result output from the output unit 70, the noise due to the excitation signal is not cancelled out from the feedback current. That is, the measurement result of the current sensor 91 contains noise due to the excitation signal.
The current sensor 92 of comparative example 2 shown in fig. 7 has two magnetic cores 10a and 10b, and two exciting coils 22a and 22 b. The current sensor 92 has a direction of a magnetic flux generated by exciting the magnetic core 10a by the exciting coil 22a and a direction of a magnetic flux generated by exciting the magnetic core 10b by the exciting coil 22b as opposite directions. In this way, noise due to the excitation signal included in the feedback current flowing through the feedback coil 32 is cancelled. As a result, the measurement result of the current sensor 92 hardly contains noise due to the excitation signal. However, the number of the magnetic cores 10 and the exciting coils 22 increases. That is, the cost of the current sensor 92 of comparative example 2 increases, and the size thereof becomes large.
On the other hand, the current sensor 1 of the present embodiment includes the integrating amplifier circuit 50 and the arithmetic circuit 60, and thereby cancels out noise due to the excitation signal included in the feedback current. The integrating and amplifying circuit 50 and the operational circuit 60 may be formed of relatively inexpensive components or circuits such as an LPF or an operational amplifier. That is, the current sensor 1 of the present embodiment is capable of improving the measurement accuracy of the current to be measured while reducing the cost and size.
Although the embodiments of the present disclosure have been described above with reference to the drawings, the specific configuration is not limited to the embodiments, and various modifications are included within the scope not departing from the gist of the present disclosure.
In the present disclosure, the X-axis, Y-axis, and Z-axis are set for convenience of explanation and may be exchanged with each other. The structure of the present disclosure is explained using an orthogonal coordinate system composed of an X axis, a Y axis, and a Z axis. The positional relationship of the structures of the present disclosure is not limited to having an orthogonal relationship.
Claims (5)
1. A current sensor having:
a magnetic core that can be disposed around the axial direction of a wire through which a current to be measured flows;
an excitation coil wound around the magnetic core;
a feedback coil wound outside the magnetic core and the exciting coil;
an exciting circuit that inputs an exciting current to the exciting coil;
a detector circuit that detects a signal corresponding to the current to be measured based on an output of the exciting coil;
a feedback circuit that outputs a feedback signal based on a signal corresponding to the current to be measured to the feedback coil;
an integral amplifier circuit that integrates an output of the exciting coil and outputs a result amplified by a predetermined magnification as a cancel signal; and
and an arithmetic circuit that subtracts the cancellation signal from a signal based on a feedback coil current flowing through the feedback coil.
2. The current sensor of claim 1,
the feedback circuit feeds a feedback current to the feedback coil as the feedback signal.
3. The current sensor of claim 1,
the magnetic core can be opened and closed.
4. The current sensor of claim 2,
the magnetic core can be opened and closed.
5. The current sensor according to any one of claims 1 to 4,
the integrating and amplifying circuit determines the prescribed magnification based on the feedback coil current and the output of the exciting coil.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2018128109A JP6826560B2 (en) | 2018-07-05 | 2018-07-05 | Current sensor |
| JP2018-128109 | 2018-07-05 |
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| CN110687339A true CN110687339A (en) | 2020-01-14 |
| CN110687339B CN110687339B (en) | 2021-07-30 |
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| CN113189384A (en) * | 2021-04-20 | 2021-07-30 | 上海科技大学 | Ripple current compensation method for sampling resistor of fluxgate current sensor |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111665383B (en) * | 2020-05-22 | 2022-06-21 | 哈尔滨工业大学 | Full-digital fluxgate type current sensor |
| CN118191394B (en) * | 2024-03-15 | 2024-08-20 | 弘乐集团有限公司 | Electronic current-voltage sensor circuit, measuring method and structure thereof |
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| CN108196159A (en) * | 2018-03-13 | 2018-06-22 | 河北博为电气股份有限公司 | A kind of DC leakage flow detection device |
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| CN113189384A (en) * | 2021-04-20 | 2021-07-30 | 上海科技大学 | Ripple current compensation method for sampling resistor of fluxgate current sensor |
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| JP2020008369A (en) | 2020-01-16 |
| CN110687339B (en) | 2021-07-30 |
| JP6826560B2 (en) | 2021-02-03 |
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