CN114252676A - Current sensor - Google Patents
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- CN114252676A CN114252676A CN202111048369.6A CN202111048369A CN114252676A CN 114252676 A CN114252676 A CN 114252676A CN 202111048369 A CN202111048369 A CN 202111048369A CN 114252676 A CN114252676 A CN 114252676A
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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
- G01R19/0092—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring current only
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Abstract
The current sensor (100) of the present invention includes: a magnetic core (101) that can be disposed so as to surround the periphery of a wire (300) through which a current to be measured flows; a magnetic sensor (102) that detects the magnetic flux inside the magnetic core (101); an amplifier (103) that amplifies the output of the magnetic sensor (102) and outputs a current corresponding to the output of the magnetic sensor (102); a feedback coil (104) wound around the core (101) and configured to flow a current output from the amplifier (103) in a direction of canceling the magnetic flux; a shunt resistor (105) arranged between the feedback coil (104) and ground (33); a differential amplifier (110) that amplifies the voltage across the shunt resistor (105); a negative output terminal (100B) that outputs the reference potential of the differential amplifier (110); and a limiting resistor (116) arranged between the negative output terminal (100B) and ground (33).
Description
Technical Field
The present invention relates to a current sensor.
Background
Conventionally, a Zero Flux (Zero Flux) type current sensor is known (for example, refer to patent document 1).
The zero-flux current sensor flows a current in a feedback coil wound around a core so as to cancel out a magnetic flux generated in the core disposed around a current to be measured.
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
It is required to improve the accuracy of the current measured by the current sensor in a zero-flux manner.
Accordingly, it is an object of the present disclosure to provide a current sensor capable of improving the accuracy of a current measured in a zero-flux manner.
Means for solving the problems
The current sensor of several embodiments includes: a magnetic core configurable to surround a circumference of a wire through which a current to be measured flows; a magnetic sensor that detects a magnetic flux inside the magnetic core; an amplifier that amplifies an output of the magnetic sensor and outputs a current corresponding to the output of the magnetic sensor; a feedback coil wound around the core and flowing a current output from the amplifier in a direction to cancel the magnetic flux; a shunt resistance configured between the feedback coil and ground (ground); a differential amplifier that amplifies a voltage across the shunt resistor; a negative output terminal that outputs a reference potential of the differential amplifier; and a limiting resistor configured between the negative output terminal and the ground. According to such a current sensor, the accuracy of the current measured in the zero-flux manner can be improved.
In the current sensor of an embodiment, the current sensor may further include a ground voltage terminal connected to a ground voltage terminal of a measuring device that measures the current detected by the current sensor. Thereby, the ground of the current sensor and the ground of the measuring device may be connected.
In the current sensor of an embodiment, the measurement device may include a measurement circuit and a power supply circuit, the negative output terminal is connected to a negative input terminal connected to an input of a negative side of the measurement circuit, and the ground voltage terminal of the measurement device is connected to a ground of the power supply circuit.
In the current sensor according to the embodiment, the resistance value of the limiting resistor may be larger than a resistance value of a 1 st wiring resistor, which is a wiring resistance of a wiring connecting the negative output terminal and the negative input terminal, and a resistance value of a 2 nd wiring resistor, which is a wiring resistance of a wiring connecting the ground voltage terminal of the current sensor and the ground voltage terminal of the measuring device. In this way, since the resistance value of the limiting resistor is larger than the resistance value of the 1 st wiring resistor and the resistance value of the 2 nd wiring resistor, the current flowing from the negative output terminal of the current sensor to the negative input terminal of the measuring device can be reduced, and the potential difference between the negative output terminal and the negative input terminal can be reduced.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the present disclosure, a current sensor capable of improving the accuracy of a current measured in a zero-flux manner can be provided.
Drawings
Fig. 1 is a schematic configuration diagram showing a state in which a current sensor according to an embodiment is connected to a measuring apparatus.
Fig. 2 is a table showing an example of the relationship between the limiting resistance and the measurement error.
Fig. 3 is a graph showing an example of the relationship between the limiting resistance and the measurement error.
Fig. 4 is a schematic configuration diagram showing a state in which a current sensor of a comparative example is connected to a measuring device.
Detailed Description
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
Fig. 1 is a schematic configuration diagram showing a state in which a current sensor 100 according to an embodiment is connected to a measuring apparatus 200. Referring to fig. 1, the structure and function of the current sensor 100 will be schematically described.
The current sensor 100 is a zero-flux mode current sensor. The current sensor 100 can detect the measured current flowing in the wire 300 in a non-contact manner. The current sensor 100 is electrically connected to the measuring device 200.
The measurement device 200 is a measurement device that measures the current detected by the current sensor 100. The measurement device 200 has a measurement circuit 210 and a power supply circuit 220.
The measurement circuit 210 is a circuit that measures the current detected by the current sensor 100. The power supply circuit 220 is a circuit for supplying power to the current sensor 100.
As terminals for electrical connection with the measurement device 200, the current sensor 100 has: a positive output terminal 100A, a negative output terminal 100B, a positive voltage input terminal 100C, a ground voltage terminal 100D, a negative voltage input terminal 100E.
The positive output terminal 100A is a terminal for outputting an output signal of a differential amplifier 110 described later. The negative output terminal 100B is a terminal that outputs a reference potential of a differential amplifier 110 described later. The positive voltage input terminal 100C is a terminal that receives supply of positive voltage from the power supply circuit 220 of the measurement device 200. The ground voltage terminal 100D is a terminal connected to the ground of the power supply circuit 220 of the measurement device 200. The negative voltage input terminal 100E is a terminal that receives supply of a negative voltage from the power supply circuit 220 of the measurement device 200.
As terminals for electrical connection with the current sensor 100, the measurement device 200 has a positive input terminal 200A, a negative input terminal 200B, a positive voltage output terminal 200C, a ground voltage terminal 200D, a negative voltage output terminal 200E.
The positive voltage output terminal 200C is a terminal for supplying the positive voltage generated by the power supply circuit 220 to the current sensor 100. The ground voltage terminal 200D is a terminal connected to the ground of the power supply circuit 220. The negative voltage output terminal 200E is a terminal for supplying the negative voltage generated by the power supply circuit 220 to the current sensor 100.
As shown in fig. 1, the negative input terminal 200B is in short circuit with the ground voltage terminal 200D in the inside of the measurement device 200.
The positive output terminal 100A of the current sensor 100 is connected to the positive input terminal 200A of the measuring device 200 by a wire such as a cable. The negative output terminal 100B of the current sensor 100 is connected to the negative input terminal 200B of the measuring device 200 by a wire such as a cable. The positive voltage input terminal 100C of the current sensor 100 is connected to the positive voltage output terminal 200C of the measurement device 200 through a cable or the like. The ground voltage terminal 100D of the current sensor 100 is connected to the ground voltage terminal 200D of the measurement device 200 through a wire such as a cable. The negative voltage input terminal 100E of the current sensor 100 is connected to the negative voltage output terminal 200E of the measuring device 200 through a wire such as a cable.
The current sensor 100 includes a magnetic core 101, a magnetic sensor 102, an amplifier 103, a feedback coil 104, a shunt resistor 105, a differential amplifier 110, and a limiting resistor 116.
The magnetic core 101 can be disposed so as to surround the periphery of the wire 300 through which the current to be measured flows. When a current to be measured flows through the wire 300, a magnetic field is generated around the current to be measured. When a magnetic field is generated around the current to be measured, a magnetic flux is generated inside the core 101.
The magnetic sensor 102 is disposed at a position magnetically couplable to the magnetic core 101. The magnetic sensor 102 detects a magnetic flux generated inside the core 101. The magnetic sensor 102 outputs a signal corresponding to the detected magnetic flux. The magnetic sensor 102 may output a signal corresponding to the detected magnetic flux as a voltage or as a current. The magnetic sensor 102 may also be any type of magnetic sensor. The magnetic sensor 102 may be a fluxgate element, a hall element, or the like, for example.
The amplifier 103 amplifies the signal output from the magnetic sensor 102 and outputs a current corresponding to the output of the magnetic sensor 102. The current output from the amplifier 103 flows through the feedback coil 104. The amplifier 103 is connected to the positive power supply 31 and the negative power supply 32. The positive power supply 31 is connected to the positive voltage input terminal 100C. The negative power supply 32 is connected to the negative voltage input terminal 100E.
The current output from the amplifier 103 is supplied from the positive power supply 31 or the negative power supply 32. From which of the positive power supply 31 and the negative power supply 32 the current output by the amplifier 103 is supplied depends on the direction of the current output by the amplifier 103. FIG. 1 shows the supply of a current I from a positive power supply 31 to an amplifier 103SThe amplifier 103 outputs a current ISThe case (1).
The feedback coil 104 is wound around and disposed on the core 101. When a current flows through the feedback coil 104, the feedback coil 104 generates a magnetic field inside the feedback coil 104. As a result, the feedback coil 104 generates a magnetic flux inside the core 101. The feedback coil 104 flows the current output from the amplifier 103 in a direction to cancel out the magnetic flux generated in the magnetic core 101 inside the magnetic core 101 by the current to be measured. That is, the feedback coil 104 is wound in a direction to cancel out the magnetic flux generated by the magnetic core 10 according to the current to be measured.
By the magnetic field generated by the feedback coil 104, the magnetic flux generated by the magnetic core 101 in accordance with the current to be measured is cancelled, whereby the magnetic flux inside the magnetic core 101 becomes substantially zero.
The shunt resistor 105 is disposed between the feedback coil 104 and the ground 33. Ground 33 is the ground of current sensor 100. One end of the shunt resistor 105 is electrically connected to the feedback coil 104. The other end of the shunt resistor 105 is electrically connected to the ground 33.
The amplifier 103 outputs a current flowing through the feedback coil 104 and the shunt resistor 105, and the current flows into the ground 33.
The current flowing through the feedback coil 104 is a current for canceling out a magnetic flux generated in the magnetic core 101 by the magnetic core 101 in accordance with the current to be measured, and is therefore proportional to the current to be measured. Therefore, the current flowing in the shunt resistor 105 is proportional to the measured current. Since the voltage across the shunt resistor 105 is proportional to the current flowing through the shunt resistor 105, the voltage across the shunt resistor 105 is proportional to the current to be measured.
In this way, by measuring the voltage across the shunt resistor 105, the value of the measured current flowing in the wire 300 can be measured. With this configuration, the current sensor 100 is a zero-flux current sensor. The zero-flux current sensor 100 can measure the value of the current to be measured with high accuracy without contacting the current to be measured, regardless of whether the current to be measured is direct current or alternating current.
The differential amplifier 110 amplifies and outputs a voltage difference of the voltages across the shunt resistor 105. The differential amplifier 110 has an input terminal 110A, an input terminal 110B, an output terminal 110C, and a reference terminal 110D.
The input terminal 110A is electrically connected to one end of the shunt resistor 105. The input terminal 110B is electrically connected to the other end of the shunt resistor 105. The output terminal 110C is electrically connected to the positive output terminal 100A. The reference terminal 110D is electrically connected to the ground 33 via a limiting resistor 116. Further, limiting resistor 116 is electrically connected to negative output terminal 100B.
The differential amplifier 110 amplifies a voltage difference between the input terminal 110A and the input terminal 110B, and outputs the amplified signal to the output terminal 110C. The reference terminal 110D outputs a reference potential of the differential amplifier 110. That is, the output signal of the differential amplifier 110 output from the output terminal 110C is a signal based on the reference potential instructed from the reference terminal 110D.
Although the input terminal 110A, the input terminal 110B, the output terminal 110C, and the reference terminal 110D are named as "terminals", they may be simple wirings having no structure like terminals.
The differential amplifier 110 has a 1 st resistor 111, a 2 nd resistor 112, a 3 rd resistor 113, a 4 th resistor 114, and an operational amplifier 115.
One end of the 1 st resistor 111 is electrically connected to the input terminal 110A. The other end of the 1 st resistor 111 is electrically connected to the inverting input terminal of the operational amplifier 115 and the 2 nd resistor 112.
One end of the 2 nd resistor 112 is electrically connected to the inverting input terminal of the operational amplifier 115 and the 1 st resistor 111. The other end of the 2 nd resistor 112 is electrically connected to the output terminal 110C.
One end of the 3 rd resistor 113 is electrically connected to the input terminal 110B. The other end of the 3 rd resistor 113 is electrically connected to the non-inverting input terminal of the operational amplifier 115 and the 4 th resistor 114.
One end of the 4 th resistor 114 is electrically connected to the non-inverting input terminal of the operational amplifier 115 and the 3 rd resistor 113. The other end of the 4 th resistor 114 is electrically connected to the reference terminal 110D.
With such a configuration, the differential amplifier 110 can output a voltage corresponding to the current flowing through the shunt resistor 105 to the positive output terminal 100A. At this time, the reference potential of the signal output from the positive output terminal 100A by the differential amplifier 110 is output from the negative output terminal 100B.
The structure of the differential amplifier 110 is not limited to the structure shown in fig. 1. The differential amplifier 110 may be a differential amplifier having another structure.
Limiting resistor 116 is disposed between reference terminal 110D and ground 33. One end of the limiting resistor 116 is electrically connected to the reference terminal 110D. One end of the limiting resistor 116 is also electrically connected to the negative output terminal 100B via the reference terminal 110D. The other end of limiting resistor 116 is electrically connected to ground 33.
Next, the flow of current in the current sensor 100 is described with reference to fig. 1.
The current I flowing in the feedback coil 104 of the amplifier 103SSupplied by the power supply circuit 220 of the measuring device 200. The current supplied from the power supply circuit 220 is supplied to the amplifier 103 via the positive voltage output terminal 200C, the positive voltage input terminal 100C, and the positive power supply 31. The amplifier 103 outputs the current supplied from the power supply circuit 220.
Current I output by amplifier 103SFlows into the ground 33 via the feedback coil 104 and the shunt resistor 105.
The current I supplied from the power supply circuit 220 of the measuring apparatus 200 and flowing into the ground 33 of the current sensor 100SAnd returns to ground of the power circuit 220 through two paths.
The 1 st path is a path returning to the ground of the power supply circuit 220 via the limiting resistor 116, the reference terminal 110D, the negative output terminal 100B, the 1 st wiring resistor 10, and the negative input terminal 200B. Here, the 1 st wiring resistance 10 is negativeThe resistance of the wiring of the output terminal 100B and the negative input terminal 200B. The wiring connecting the negative output terminal 100B and the negative input terminal 200B may be, for example, a cable. In the 1 st path, current IPAnd (4) flowing.
The 2 nd path is a path returning to the ground of the power supply circuit 220 via the ground voltage terminal 100D, the 2 nd wiring resistor 20, and the ground voltage terminal 200D. Here, the 2 nd wiring resistor 20 is a resistor of a wiring connecting the ground voltage terminal 100D and the ground voltage terminal 200D. The wiring connecting the ground voltage terminal 100D and the ground voltage terminal 200D may be, for example, a cable. In the 2 nd path, current IRAnd (4) flowing.
Current I supplied from power supply circuit 220 to amplifier 103SThe ground of the power circuit 220 is returned through two paths, path 1 and path 2. Therefore, the current I supplied from the power supply circuit 220 to the amplifier 103SA current I flowing through the 1 st pathPA current I flowing through the 2 nd pathRThe following relationship holds.
IS＝IP+IR
The resistance value of the 1 st path is the sum of the resistance value of the limiting resistor 116 and the resistance value of the 1 st wiring resistor 10. The resistance value of the 2 nd path is the resistance value of the 2 nd wiring resistor 20. Here, the resistance value of the limiting resistor 116 is a value sufficiently larger than the resistance value of the 1 st wiring resistor 10 and the resistance value of the 2 nd wiring resistor 20.
The 1 st wiring resistor 10 and the 2 nd wiring resistor 20 are wiring resistors such as cables, and are resistance values of, for example, about several 10m Ω. The limiting resistor 116 is a resistor having a sufficiently larger resistance value than it. The limiting resistor 116 may be, for example, a chip resistor.
Since the resistance value of the limiting resistor 116 is sufficiently larger than the resistance value of the 1 st wiring resistor 10 and the resistance value of the 2 nd wiring resistor 20, the resistance value of the 1 st path is also larger than the resistance value of the 2 nd path. As a result, the current I supplied by the power circuit 220SSubstantially through path 2 back to ground of the power circuit 220. I.e. the current I flowing in the 1 st pathPBecomes a very small current.
If atCurrent I flowing through path 1PWhen the voltage becomes smaller, the potential difference between the negative output terminal 100B and the negative input terminal 200B becomes smaller. As a result, the measurement error when the measurement circuit 210 measures the measurement target current detected by the current sensor 100 is reduced. This is because the output signal output from the positive output terminal 100A by the differential amplifier 110 is a signal based on the potential of the negative output terminal 100B, and the measurement circuit 210 measures the signal input to the terminal at the positive input terminal 200A based on the potential of the negative input terminal 200B.
(calculation example of measurement error)
Fig. 2 and 3 show an example of the relationship between the resistance value of the limiting resistor 116 and the measurement error. Fig. 2 shows the calculation results as a table. Fig. 3 shows the calculation results as a graph.
The results shown in fig. 2 and 3 are calculated on the assumption that the following conditions are set.
< Condition >
The 1 st resistor 111 is 10k Ω
The 2 nd resistor 112 is 40k Ω
The 3 rd resistor 113 is 10k Ω
The 4 th resistor 114 is 40k Ω
1 st wiring resistance 10 is 20m Ω
The 2 nd wiring resistance 20 is 60m Ω
IS＝400mA
As shown in fig. 2 and 3, the measurement error is inversely proportional to the resistance value of the limiting resistor 116. Therefore, as the resistance value of the limiting resistor 116 becomes larger, the measurement error becomes smaller. However, as the resistance value of the limiting resistor 116 becomes larger, the measurement error becomes slower to decrease.
When there is a target value of the measurement error, the resistance value of the limiting resistor 116 may be a resistance value that can achieve the target value of the measurement error.
If the resistance value of the limiting resistor 116 is excessively increased, the risk of the differential amplifier 110 being affected by disturbance increases. Therefore, it is desirable that the resistance value of the limiting resistor 116 not be increased more than necessary. The resistance value of the limiting resistor 116 is preferably about several ohms, for example.
The limiting resistor 116 does not need to be a high-precision resistor as the 1 st resistor 111, the 2 nd resistor 112, the 3 rd resistor 113, and the 4 th resistor 114. The limiting resistor 116 may have a small resistance value of about several Ω, and may be a general small resistor because the current flowing through the resistor is small. That is, the limiting resistor 116 may be an inexpensive small resistor.
Comparative example
Fig. 4 shows a current sensor 400 of a comparative example. The current sensor 400 of the comparative example is different from the current sensor 100 shown in fig. 1 in that the limiting resistor 116 included in the current sensor 100 shown in fig. 1 is not included.
The 4 th resistor 114 of the differential amplifier 410 included in the current sensor 400 of the comparative example is directly connected to the ground 33 without the limiting resistor 116 as shown in fig. 1.
Therefore, when the current to be measured flowing through the wire 300 is measured with the configuration shown in fig. 4, the resistance value of the 1 st path is the resistance value of the 1 st wiring resistance 10. The resistance value of the 2 nd path is the resistance value of the 2 nd wiring resistor 20. That is, the resistance value of the 1 st path is substantially the same as the resistance value of the 2 nd path.
Therefore, in the structure of the comparative example, the current I flowing through the 1 st pathPWith the current I flowing in the 2 nd pathRThe current I flowing through the 1 st path is substantially the samePThe power supply circuit 220 supplies about half of the current to the current sensor 400.
In the comparative example, since such a large current flows in the 1 st path, the potential difference between the negative output terminal 100B and the negative input terminal 200B becomes large. That is, since the difference between the potential of the negative output terminal 100B, which is the reference for the output of the differential amplifier 110, and the potential of the negative input terminal 200B, which is the reference for measurement by the measurement circuit 210, is large, the measurement error of the measurement by the measurement circuit 210 is large.
The current sensor 100 of the present embodiment has the limiting resistor 116, and thus can reduce a measurement error as compared with the current sensor 400 of the comparative example.
According to the current sensor 100 of the above-described embodiment, the accuracy of the current measured by the zero-flux method can be improved. More specifically, the current sensor 100 is a zero-flux current sensor including: a magnetic core 101 capable of being disposed so as to surround the periphery of a wire 300 through which a current to be measured flows; a magnetic sensor 102 that detects a magnetic flux inside the core 101; an amplifier 103 that amplifies an output of the magnetic sensor 102 and outputs a current corresponding to the output of the magnetic sensor 102; a feedback coil 104 wound around the core 101 and configured to flow a current output from the amplifier 103 in a direction of canceling the magnetic flux; a shunt resistor 105 arranged between the feedback coil 104 and the ground 33; and a differential amplifier 110 that amplifies the voltage across the shunt resistor 105. Since current sensor 100 includes limiting resistor 116 disposed between negative output terminal 100B and ground 33, the current flowing from negative output terminal 100B to negative input terminal 200B can be reduced, and the potential difference between negative output terminal 100B and negative input terminal 200B can be reduced, so that the error in measuring the current detected by current sensor 100 by measuring device 200 can be reduced.
In addition, in the current sensor 100, since the limiting resistor 116 may be a general-purpose resistance element, an error in measuring a current can be reduced at low cost. Since the limiting resistor 116 may be a chip resistor, for example, the limiting resistor 116 can be introduced into a small assembly space.
As those skilled in the art will appreciate, the present disclosure may be implemented in other prescribed ways than the above-described embodiments without departing from the spirit or essential characteristics thereof. Therefore, the foregoing description is illustrative and not restrictive. The scope of the disclosure is defined not by the foregoing description but by the appended claims. And among all variations, several variations are included within their scope of equivalents.
For example, the arrangement, number, and the like of the respective components are not limited to those described above and illustrated in the drawings. The arrangement, number, and the like of each component may be arbitrarily configured as long as the function thereof can be realized.
In the above-described embodiment, the case where the power supply circuit 220 supplies current to the positive power supply 31 of the current sensor 100 via the positive voltage output terminal 200C and the positive voltage input terminal 100C has been described as an example, but the power supply circuit 220 may supply current to the negative power supply 32 of the current sensor 100 via the negative voltage output terminal 200E and the negative voltage input terminal 100E.
Description of the reference symbols
10 st 1 st wiring resistor
20 nd 2 nd wiring resistance
31 positive power supply
32 negative power supply
33 ground
100 current sensor
100A positive output terminal
100B negative output terminal
100C positive voltage input terminal
100D ground voltage terminal
100E negative voltage input terminal
101 magnetic core
102 magnetic sensor
103 amplifier
104 feedback coil
105 shunt resistor
110 differential amplifier
110A input terminal
110B input terminal
110C output terminal
110D reference terminal
111 st resistance
112 nd 2 nd resistor
113 rd resistance
114 th resistance
115 operational amplifier
116 limiting resistance
200 measuring device
200A positive input terminal
200B negative input terminal
200C positive voltage output terminal
200D ground voltage terminal
200E negative voltage output terminal
210 measurement circuit
220 power supply circuit
300 conducting wire
400 current sensor
410 differential amplifier.
Claims (4)
1. A current sensor, comprising:
a magnetic core that can be disposed so as to surround a periphery of a wire through which a current to be measured flows;
a magnetic sensor that detects a magnetic flux inside the magnetic core;
an amplifier that amplifies an output of the magnetic sensor and outputs a current corresponding to the output of the magnetic sensor;
a feedback coil wound around the core and configured to flow a current output from the amplifier in a direction to cancel the magnetic flux;
a shunt resistor configured between the feedback coil and ground;
a differential amplifier that amplifies a voltage across the shunt resistor;
a negative output terminal that outputs a reference potential of the differential amplifier; and
a limiting resistor disposed between the negative output terminal and the ground.
2. The current sensor of claim 1,
the current sensor further includes a ground voltage terminal connected to a ground voltage terminal of a measuring device that measures the current detected by the current sensor.
3. The current sensor of claim 2,
the measuring device comprises a measuring circuit and a power supply circuit,
the negative output terminal is connected with a negative input terminal connected to an input of the negative side of the measurement circuit,
the ground voltage terminal of the measurement device is connected to a ground of the power supply circuit.
4. The current sensor of claim 3,
the limiting resistor has a resistance value larger than a resistance value of a 1 st wiring resistor, which is a wiring resistance of a wiring connecting the negative output terminal and the negative input terminal, and a resistance value larger than a resistance value of a 2 nd wiring resistor, which is a wiring resistance of a wiring connecting the ground voltage terminal of the current sensor and the ground voltage terminal of the measuring device.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020-161336 | 2020-09-25 | ||
| JP2020161336A JP7216058B2 (en) | 2020-09-25 | 2020-09-25 | current sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114252676A true CN114252676A (en) | 2022-03-29 |
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| CN202111048369.6A Pending CN114252676A (en) | 2020-09-25 | 2021-09-08 | Current sensor |
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Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000097972A (en) * | 1998-09-25 | 2000-04-07 | Asahi Kasei Denshi Kk | Current sensor |
| JP4771094B2 (en) | 2008-01-17 | 2011-09-14 | Ｔｄｋ株式会社 | Magnetic balanced current sensor |
| JP2012225664A (en) | 2011-04-15 | 2012-11-15 | Tdk Corp | Current sensor and current detection method |
| JP6605007B2 (en) * | 2017-10-12 | 2019-11-13 | 株式会社タムラ製作所 | Current detector |
| CN207380115U (en) | 2017-10-20 | 2018-05-18 | 吉林大学 | A kind of novel high-precision low noise D.C. high-current detection device |
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| JP7216058B2 (en) | 2023-01-31 |
| JP2022054256A (en) | 2022-04-06 |
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