JP5678285B2 - Current sensor - Google Patents

Description

  The present invention relates to a current sensor that measures the magnitude of a current, and more particularly to a current sensor that detects a current flowing through a conductor via a magnetoelectric transducer.

  In recent years, in the fields of electric vehicles and solar batteries, the current value handled has increased with the increase in output and performance of electric vehicles and solar battery devices. Sensors are widely used. As such a current sensor, a sensor including an electromagnetic conversion element that detects a current flowing through a conductor to be detected through a change in a magnetic field around the conductor has been proposed.

  In such a current sensor, a pair of magnetic collecting cores are arranged on both sides of the electromagnetic conversion element, and a magnetic flux generated from a conductor is collected by the pair of magnetic collecting cores so as to have a small size and high sensitivity. (Patent Document 1).

JP 2005-147755 A

  However, in the current sensor described in Patent Document 1, there is a problem that the sensitivity is easily changed due to a disturbance magnetic field in a direction orthogonal to the sensitivity axis direction of the electromagnetic transducer, and the current detection range is narrowed because the sensitivity is increased. There is a problem.

  The present invention has been made in view of such points, and an object thereof is to provide a current sensor having a wide current detection range while reducing an error caused by an external magnetic field.

The current sensor of the present invention is disposed in the vicinity of a conductor through which current is passed, and has a magnetic sensor having a sensitivity axis in a direction orthogonal to the current supply direction, and is disposed outside the magnetic sensor in the sensitivity axis direction. A pair of magnetic flux collecting cores, and a pair of magnetic shields disposed outside the magnetic flux collecting cores and extending in the energizing direction, wherein the magnetic flux collecting cores and the magnetic shields are integrally formed. is formed, characterized in Rukoto.

  According to this configuration, it is possible to increase sensitivity while eliminating the influence of a magnetic field in a direction (energization direction) orthogonal to the sensitivity axis direction. Thereby, it is possible to realize a current sensor capable of accurately detecting even a low current.

  In the current sensor according to the present invention, the current sensor is disposed inside the pair of magnetic shields without having a magnetic core in the sensitivity axis direction, and has a sensitivity axis in a direction orthogonal to the energization direction. It is preferable to have a magnetic sensor. According to this configuration, a low current can be detected with high sensitivity by the magnetic sensor in which the magnetic flux collecting core is arranged, and a high current can be detected with high accuracy by the other magnetic sensor. Thereby, a current sensor with a wide current detection range can be realized.

In the current sensor of the present invention, the magnetic sensor is disposed in the vicinity of a conductor through which a current is passed, and has a sensitivity axis in a direction orthogonal to the direction in which the current is passed, and outside the magnetic sensor in the sensitivity axis direction A pair of magnetic flux collecting cores, a pair of magnetic shields arranged outside the magnetic flux collecting cores and extending in the energizing direction, and inside the pair of magnetic shields, in the sensitivity axis direction And another magnetic sensor having a sensitivity axis in a direction orthogonal to the energizing direction, and having no magnetic flux collecting core, and another pair of magnetic flux collecting cores inside the pair of magnetic shields the provided, the other pair of magnetism collection core you wherein another magnetic sensor is disposed so as to be positioned between the pair of magnetism collecting core in the current direction.

  In the current sensor of the present invention, it is preferable that the magnetic sensor and / or the other magnetic sensor are two magnetic sensors whose sensitivity axis directions are different from each other by 180 degrees. According to this configuration, since the temperature drift can be canceled by the two magnetic sensors whose sensitivity axis directions are different from each other by 180 degrees, it is possible to detect the current with higher accuracy.

  In the current sensor of the present invention, the pair of current sensors are arranged to face each other with a conductor interposed therebetween, and the sensitivity axis directions of the magnetic sensors in the pair of current sensors are the same. According to this configuration, since the external magnetic field in the sensitivity axis direction can be canceled, more accurate current detection can be performed.

  The current sensor of the present invention is disposed in the vicinity of a conductor through which current is passed, and has a magnetic sensor having a sensitivity axis in a direction orthogonal to the current supply direction, and is disposed outside the magnetic sensor in the sensitivity axis direction. A pair of magnetic flux collecting cores and a pair of magnetic shields arranged outside the magnetic flux collecting cores and extending in the energizing direction, so that the current detection range is reduced while reducing errors due to an external magnetic field. Can be widened.

It is a figure which shows the current sensor which concerns on Embodiment 1 of this invention, (a) is an internal see-through | perspective side view, (b) is an internal see-through | perspective plan view. (A), (b) is a figure for demonstrating the effect of the current sensor which concerns on embodiment of this invention. It is a figure which shows the current sensor which concerns on Embodiment 2 of this invention, (a) is an internal perspective side view, (b) is an internal perspective top view. It is an internal perspective top view which shows the current sensor which concerns on Embodiment 3 of this invention. It is an internal perspective top view which shows the current sensor which concerns on Embodiment 4 of this invention. It is an internal perspective top view which shows the current sensor which concerns on Embodiment 5 of this invention. It is an internal see-through | perspective side view which shows the current sensor which concerns on Embodiment 6 of this invention. It is a figure for demonstrating the magnetic field direction about the current sensor which concerns on Embodiment 6 of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
(Embodiment 1)
1A and 1B are diagrams showing a current sensor according to Embodiment 1 of the present invention, in which FIG. 1A is an internal perspective side view, and FIG. 1B is an internal perspective plan view.

  As shown in FIG. 1A, a current sensor 1 is disposed in the vicinity of a conductor 2 through which a current is passed. This current sensor 1 is mounted on a conductor 2 via a spacer 3. The current sensor 1 may not be directly disposed on the conductor 2 as long as the current flowing through the conductor 2 can be measured.

  A magnetic sensor 12 is disposed on the substrate 11 of the current sensor 1. The magnetic sensor 12 is arranged at the center of the current sensor 1 as shown in FIG. Further, the magnetic sensor 12 has a sensitivity axis in a direction orthogonal to the direction of current application (the direction of the magnetic field generated by the current). A pair of magnetic collecting cores 13 is disposed on the substrate 11 outside the magnetic sensor 12 in the sensitivity axis direction. That is, the pair of magnetism collecting cores 13 are arranged so as to sandwich the magnetic sensor 12. On the substrate 11, a pair of magnetic shields 14 are disposed outside the magnetic flux collecting core 13. That is, the pair of magnetic shields 14 are disposed so as to sandwich the pair of magnetic collecting cores 13 and the magnetic sensor 12. Each of the pair of magnetic shields 14 extends in the energization direction. In addition, a signal processing circuit (not shown) for converting the output of the magnetic sensor 12 into a desired output signal format is provided on the substrate 11, and this signal processing circuit is electrically connected to the magnetic sensor 12. Has been. The current sensor 1 is packaged by a housing 10.

  As the housing 10, a package used for electronic component packaging is used. As the substrate 11, a substrate used for a substrate of an electronic component is used. As the spacer 3, for example, ceramic or insulating resin is used.

  As the magnetic sensor 12, a magnetoresistive element (GMR element (giant magnetoresistive element), TMR element (tunnel type magnetoresistive element), AMR element (anisotropic magnetoresistive element), Hall element, or the like may be used. it can.

  The magnetic shield 14 extends in a direction orthogonal to the sensitivity axis direction, collects an external magnetic field along the longitudinal direction along the longitudinal direction, and a direction perpendicular to the detection magnetic field in the sensitivity axis direction. Collect in the magnetic core 13 inside the pair of magnetic shields 14 through (width direction). Examples of the material of the magnetic shield 14 include ferrite, permalloy, silicon steel, and the like.

The thickness t ₂ of the magnetic shield 14 is preferably 10 times or more the thickness t ₁ of the magnetic sensor 12. Here, the relationship between the ratio of the thickness t ₂ of the magnetic shield 14 to the thickness t ₁ of the magnetic sensor 12 and the magnetic field shield rate in the direction orthogonal to the sensitivity axis direction was examined. Specifically, a current sensor in which the thickness t ₁ of the thickness t ₂ and the magnetic sensor 12 of the magnetic shield 14 and the same (1 time), the thickness t ₂ of the magnetic shield 14 of the magnetic sensor 12 thickness t _The magnetic field shield ratio was examined for a current sensor that was 10 times as large as ₁ . The magnetic field shield rate was obtained by measuring the magnetic field applied from the orthogonal direction with a magnetic sensor (arranged so that the sensitivity axis is in the direction of current application) while changing the shield. The results are shown in Table 1. As can be seen from Table 1, when the thickness t ₂ of the magnetic shield 14 is 10 times the thickness t ₁ of the magnetic sensor 12, the magnetic field shielding factor is very high (about 1/2 of the magnetic field shielding factor is (Improved to 1/10 or less).

  Moreover, it is preferable that the magnetic sensor 12 is arrange | positioned in the approximate center position of the magnetic shield 14 in an electricity supply direction, as shown in FIG.1 (b). Thus, by defining the thickness of the magnetic shield 14 and the position of the magnetic sensor 12 with respect to the magnetic shield 14, it is possible to further reduce the influence of the magnetic field in the direction orthogonal to the sensitivity axis direction. Current detection is possible.

  The magnetic flux collecting core 13 focuses the detected magnetic field that has passed through the magnetic shield 14 onto the magnetic sensor 12. That is, the magnetic flux collecting core 13 collects magnetic flux between the magnetic shield 14 and the magnetic sensor 12. Examples of the material of the magnetism collecting core 13 include ferrite, permalloy, silicon steel, and the like.

  2A and 2B are diagrams for explaining the effect of the current sensor according to the embodiment of the present invention, and are diagrams showing the magnetic field distribution in the current sensor shown in FIG. When an external magnetic field in the same direction as the energization direction (direction orthogonal to the sensitivity axis direction) is applied to the current sensor according to the present embodiment, the external magnetic field is converted into a pair of magnetic shields 14 as shown in FIG. Magnetized. At this time, the magnetic shield 14 has a shape extending long in the energization direction and is sufficiently longer than the size of the magnetic sensor 12, so that an external magnetic field is prevented from reaching the magnetic sensor 12. it can. For this reason, the magnetic sensor 12 is not affected by the external magnetic field, and the detection error due to the external magnetic field is reduced. On the other hand, when a detection magnetic field in the sensitivity axis direction (magnetic field generated by current) is applied to the current sensor according to the present embodiment, the detection magnetic field passes through the magnetic shield 14 as shown in FIG. The magnetic flux is collected by the magnetic flux collecting core 13. Thereby, the magnetic flux added to the magnetic sensor 12 becomes large. As a result, the current can be detected with high sensitivity even for a magnetic field generated with a small current.

  Thus, according to the current sensor according to the present embodiment, it is possible to increase sensitivity while eliminating the influence of a magnetic field in a direction orthogonal to the sensitivity axis direction (energization direction). Thereby, it is possible to realize a current sensor capable of accurately detecting even a low current.

(Embodiment 2)
3A and 3B are diagrams showing a current sensor according to Embodiment 2 of the present invention, in which FIG. 3A is an internal perspective side view, and FIG. 3B is an internal perspective plan view. 3, the same parts as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and the detailed description thereof is omitted.

  In the current sensor 1 shown in FIG. 3, a substantially T-shaped magnetic layer 15 is formed in a plan view. The magnetic layer 15 includes an extending portion 15a extending along the energization direction and an extending portion 15b extending from the extending portion 15a side to the magnetic sensor 12 side. Such a magnetic layer 15 is formed by integrally forming a magnetic flux collecting core and a magnetic shield. Since the same material can be used as the material for the magnetic flux collecting core and the magnetic shield, the magnetic flux collecting core and the magnetic shield can be integrated as in the present embodiment. As a result, the manufacturing process can be simplified.

  When an external magnetic field in the same direction as the energization direction (a direction orthogonal to the sensitivity axis direction) is applied to the current sensor according to the present embodiment, the external magnetic field is collected by the extending portion 15a of the magnetic layer 15 and magnetic sensor 12 Reaching is prevented. On the other hand, when a detection magnetic field in the sensitivity axis direction (a magnetic field generated by a current) is applied to the current sensor according to the present embodiment, the detection magnetic field is collected by the extension 15b via the extension 15a. Thereby, the magnetic flux added to the magnetic sensor 12 becomes large. Thereby, the current can be detected with high sensitivity even for a magnetic field generated with a small current. As described above, even in the current sensor according to the present embodiment, the sensitivity can be improved while eliminating the influence of the magnetic field in the direction (energization direction) orthogonal to the sensitivity axis direction, and the current can be accurately detected. can do.

(Embodiment 3)
FIG. 4 is an internal perspective plan view showing a current sensor according to Embodiment 3 of the present invention. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and detailed description thereof is omitted.

  In the current sensor 1 shown in FIG. 4, another magnetic sensor 16 is disposed inside the pair of magnetic shields 14 and without the magnetic flux collecting core in the sensitivity axis direction. This magnetic sensor 16 also has a sensitivity axis in a direction orthogonal to the energization direction. That is, the magnetic sensor 16 is not located in a region between the magnetic flux collecting cores 13. Therefore, the current sensor 1 according to the present embodiment includes the magnetic sensor 12 positioned between the pair of magnetic cores 13 and the magnetic sensor 16 not positioned between the pair of magnetic cores 13. This magnetic sensor 16 is also electrically connected to a signal processing circuit on the substrate 11. According to this configuration, a low current can be detected with high sensitivity by the magnetic sensor 12 in which the magnetic flux collecting core 13 is disposed, and a high current can be detected with high sensitivity by the other magnetic sensor 16. Thereby, a current sensor with a wide current detection range can be realized.

  When measuring a low current with the current sensor according to the present embodiment, if an external magnetic field in the same direction as the energization direction (direction orthogonal to the sensitivity axis direction) is applied, the external magnetic field is collected by the magnetic shield 14 and magnetized. Reaching the sensor 12 is prevented. On the other hand, when a low magnetic field is measured by the current sensor according to the present embodiment, if a detection magnetic field in the sensitivity axis direction (magnetic field generated by current) is applied, the detection magnetic field passes through the magnetic shield 14 and the magnetic collecting core 13. Magnetized. Thereby, the magnetic flux added to the magnetic sensor 12 becomes large. Thereby, the current can be detected with high sensitivity even for a magnetic field generated with a small current. Further, when a high current is measured by the current sensor according to the present embodiment, if an external magnetic field in the same direction as the energization direction (a direction orthogonal to the sensitivity axis direction) is applied, the external magnetic field is collected on the magnetic shield 14. Thus, reaching the magnetic sensor 12 is prevented. On the other hand, when measuring a high current with the current sensor according to the present embodiment, if a detection magnetic field in the sensitivity axis direction (a magnetic field generated by current) is applied, the detection magnetic field passes through the magnetic shield 14 and is detected by the magnetic sensor 16. Detected. At this time, the magnetic field detected by the magnetic sensor 16 is not collected by the magnetic collecting core 13. As described above, a low current output can be obtained by the magnetic sensor 12, and a high current output can be obtained by the magnetic sensor 16, so that the current detection range can be widened.

(Embodiment 4)
FIG. 5 is an internal perspective plan view showing a current sensor according to Embodiment 4 of the present invention. In FIG. 5, the same parts as those in FIG. 4 are denoted by the same reference numerals as those in FIG.

  In the current sensor 1 shown in FIG. 5, another pair of magnetic flux collecting cores 17 is provided inside the pair of magnetic shields 14. The other pair of magnetism collecting cores 17 are arranged so that the other magnetic sensor 16 is positioned between the pair of magnetism collecting cores 13 in the energizing direction. That is, there is no magnetic sensor between the pair of magnetic collecting cores 17 in the sensitivity axis direction. Therefore, the current sensor 1 according to the present embodiment includes a pair of magnetic flux collecting cores 13 in which the magnetic sensor 12 exists in the sensitivity axis direction and a pair of magnetic flux collecting cores 17 in which no magnetic sensor exists in the sensitivity axis direction. And have. This makes it possible to detect a higher current than the configuration according to the third embodiment.

  When measuring a low current with the current sensor according to the present embodiment, if an external magnetic field in the same direction as the energization direction (direction orthogonal to the sensitivity axis direction) is applied, the external magnetic field is collected by the magnetic shield 14 and magnetized. Reaching the sensor 12 is prevented. On the other hand, when a low magnetic field is measured by the current sensor according to the present embodiment, if a detection magnetic field in the sensitivity axis direction (magnetic field generated by current) is applied, the detection magnetic field passes through the magnetic shield 14 and the magnetic collecting core 13. Magnetized. Thereby, the magnetic flux added to the magnetic sensor 12 becomes large. Thereby, the current can be detected with high sensitivity even for a magnetic field generated with a small current. Further, when a high current is measured by the current sensor according to the present embodiment, if an external magnetic field in the same direction as the energization direction (a direction orthogonal to the sensitivity axis direction) is applied, the external magnetic field is collected on the magnetic shield 14. Thus, reaching the magnetic sensor 12 is prevented. On the other hand, when measuring a high current with the current sensor according to the present embodiment, if a detection magnetic field in the sensitivity axis direction (a magnetic field generated by current) is applied, the detection magnetic field passes through the magnetic shield 14 and is detected by the magnetic sensor 16. Detected. At this time, the magnetic field detected by the magnetic sensor 16 is not collected by the magnetic collecting core 13. Further, the magnetic field applied to the magnetic sensor 16 is reduced because it is collected by the magnetic collecting core 13 and the magnetic collecting core 17. For this reason, it becomes possible to detect a higher current. As described above, a low current output is obtained by the magnetic sensor 12, and a high current output is obtained by the magnetic sensor 16, so that the current detection range can be further widened.

(Embodiment 5)
FIG. 6 is an internal perspective plan view showing a current sensor according to Embodiment 5 of the present invention. In FIG. 6, the same parts as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and detailed description thereof will be omitted.

  In the current sensor 1 shown in FIG. 6, two magnetic sensors 12 and 18 whose sensitivity axis directions are different from each other by 180 degrees are disposed inside the pair of magnetic collecting cores 13. That is, the magnetic sensors 12 and 18 are methods orthogonal to the energization direction, and each has a sensitivity axis in a direction that is 180 degrees different (opposite direction). This magnetic sensor 18 is also electrically connected to the signal processing circuit on the substrate 11. Thereby, the temperature drift added to each magnetic sensor 12 and 18 can be canceled. As a result, it is possible to detect current with higher accuracy.

  When an external magnetic field in the same direction as the energization direction (direction orthogonal to the sensitivity axis direction) is applied to the current sensor according to the present embodiment, the external magnetic field is collected by the magnetic shield 14 and reaches the magnetic sensors 12 and 18. It is prevented. On the other hand, when a detection magnetic field in the sensitivity axis direction (a magnetic field generated by a current) is applied to the current sensor according to the present embodiment, the detection magnetic field passes through the magnetic shield 14 and is collected by the magnetic collection core 13. Thereby, the magnetic flux added to the magnetic sensors 12 and 18 becomes large. Thereby, the current can be detected with high sensitivity even for a magnetic field generated with a small current. Further, by taking the difference between the outputs of the magnetic sensors 12 and 18, the sensitivity can be improved and the temperature drift can be canceled. As described above, also in the current sensor according to the present embodiment, it is possible to further increase the sensitivity while eliminating the influence of the magnetic field in the direction orthogonal to the sensitivity axis direction (energization direction), and to accurately reduce the current. Can be detected.

(Embodiment 6)
FIG. 7 is an internal perspective plan view showing a current sensor according to Embodiment 6 of the present invention. In FIG. 7, the same parts as those in FIG. 1 are denoted by the same reference numerals as those in FIG.

  The current sensor shown in FIG. 7 is formed by arranging a pair of current sensors 1 a and 1 b to face each other with a conductor 2 interposed therebetween. That is, the current sensor shown in FIG. 7 includes a magnetic sensor 12a, a pair of magnetic flux collecting cores 13a, and a pair of magnetic shields 14a on the substrate 11a, and the current sensor 1a packaged by the housing 10a and the substrate 11b. A current sensor 1b including a magnetic sensor 12b, a pair of magnetic collecting cores 13b, and a pair of magnetic shields 14b and packaged by a housing 10b is disposed on the conductor 2 via spacers 3a and 3b, respectively. . The housings 10 a and 10 b are fixed with bolts 19. In this case, the magnetic sensor 12a of the current sensor 1a and the magnetic sensor 12b of the current sensor 1b are each electrically connected to the signal processing circuit. The sensitivity axis directions of the magnetic sensors 12a and 12b in the pair of current sensors 1a and 1b are the same. According to this configuration, an external magnetic field (disturbance magnetic field such as geomagnetism) in the sensitivity axis direction can be canceled, so that more accurate current detection can be performed.

  When an external magnetic field in the same direction as the energization direction (direction orthogonal to the sensitivity axis direction) is applied to the current sensors 1a and 1b according to the present embodiment, the external magnetic field is collected by the magnetic shields 14a and 14b, and the magnetic sensor 12a. , 12b is prevented. On the other hand, when a detection magnetic field in the sensitivity axis direction (magnetic field generated by current) is applied to the current sensor according to the present embodiment, the detection magnetic field passes through the magnetic shields 14a and 14b and is collected in the magnetic collection cores 13a and 13b. Is done. This increases the magnetic flux applied to the magnetic sensors 12a and 12b. Thereby, the current can be detected with high sensitivity even for a magnetic field generated with a small current. Further, by taking the difference between the outputs of the magnetic sensors 12a and 12b, a disturbance magnetic field such as geomagnetism can be canceled and detection accuracy can be improved (see FIG. 8). As described above, also in the current sensor according to the present embodiment, it is possible to further increase the sensitivity while eliminating the influence of the magnetic field in the direction orthogonal to the sensitivity axis direction (energization direction), and to accurately reduce the current. Can be detected.

Next, examples performed for clarifying the effects of the present invention will be described.
Regarding the current sensor (example) having the configuration shown in FIG. 1, the sensitivity when a current of 100 A is passed through the conductor 2 and the influence of the disturbance magnetic field in an environment with a disturbance magnetic field of 1 mT perpendicular to the sensitivity axis Examined. The results are shown in Table 2. Further, for the current sensor (comparative example) in which the magnetic shield 14 is not provided in the configuration shown in FIG. The results are also shown in Table 2.

  As can be seen from Table 2, according to the current sensor of the example, the error due to the external magnetic field could be reduced.

  The present invention is not limited to the above embodiment, and can be implemented with various modifications. For example, the material, thickness, size, manufacturing method, and the like in the above embodiment can be changed as appropriate. In addition, the present invention can be implemented with appropriate modifications without departing from the scope of the present invention.

  The present invention can be applied to a current sensor for current detection such as an electric vehicle or a solar battery.

1, 1a, 1b Current sensor 2 Conductor 3, 3a, 3b Spacer 10, 10a, 10b Housing 11, 11a, 11b Substrate 12, 12a, 12b, 16, 18 Magnetic sensor 13, 13a, 13b, 17 Magnetic collecting core 14, 14a, 14b Magnetic shield 15 Magnetic layer 15a Extension part 15b Extension part 19 Bolt

Claims (5)

A magnetic sensor having a sensitivity axis in a direction orthogonal to a current application direction, and a pair of magnetic flux collecting cores arranged outside the magnetic sensor in the sensitivity axis direction; And a pair of magnetic shields disposed outside the magnetic flux collecting core and extending in the energizing direction ,
A current sensor and the magnetic shield and the magnetic flux collecting core is characterized that you have been formed integrally.   Another magnetic sensor having a sensitivity axis in a direction orthogonal to the energization direction, disposed inside the pair of magnetic shields without having a magnetic core in the sensitivity axis direction. The current sensor according to claim 1. A magnetic sensor having a sensitivity axis in a direction orthogonal to a current application direction, and a pair of magnetic flux collecting cores arranged outside the magnetic sensor in the sensitivity axis direction; And a pair of magnetic shields arranged outside the magnetism collecting core and extending in the energization direction;
Another magnetic sensor disposed inside the pair of magnetic shields without having a magnetic core in the sensitivity axis direction and having a sensitivity axis in a direction orthogonal to the energization direction. ,
Another pair of magnetic flux collecting cores is provided inside the pair of magnetic shields, and the other magnetic flux collecting core is positioned between the other magnetic sensor and the pair of magnetic flux collecting cores in the energization direction. The current sensor is arranged as described above.   The current sensor according to claim 1, wherein the magnetic sensor and / or the other magnetic sensor are two magnetic sensors whose sensitivity axis directions are different from each other by 180 degrees. The pair of current sensors according to any one of claims 1 to 4 are disposed to face each other with a conductor interposed therebetween, and the sensitivity axis directions of the magnetic sensors in the pair of current sensors are the same. And current sensor.

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