Current sensor and electronic device incorporating the same

Patent metadata

Field	Value
Publication number	US-9714959-B2
Application number	US-201514831018-A
Country	US
Kind code	B2
Filing date	Aug 20, 2015
Priority date	Feb 27, 2013
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

A busbar module including a busbar through which current of a measurement subject flows and a hold portion that holds the busbar and has a recess portion), the busbar and the hold portion being integrally formed; and a magnetic sensor module including a magnetic sensor that detects an intensity of a magnetic field generated by the current flowing through the busbar, and being able to be selectively assembled with the busbar module by housing the magnetic sensor module to the recess portion of the hold portion are included.

First claim

The invention claimed is:

1. A current sensor, comprising:
a housing;
a busbar extending through and being integral with the housing, the housing having a recess; and
a magnetic sensor module located in the recess and including a magnetic sensor having odd function input/output characteristics, the magnetic sensor being configured to detect an intensity of a magnetic field generated by current flowing through the busbar.

2. The current sensor according to claim 1 , wherein:
the recess of the housing comprises a fitting structure; and
the magnetic sensor module has an outer shape that corresponds to a shape of the fitting structure.

3. The current sensor according to claim 2 , wherein the busbar module includes an electrical device held by the housing together with the busbar in a state in which the electrical device is coupled to the busbar.

4. The current sensor according to claim 1 , wherein the magnetic sensor module further includes a calculating circuit configured to calculate a value of the current by arithmetically operating a detection value of the magnetic sensor.

5. The current sensor according to claim 4 , wherein the recess is a first recess and the magnetic sensor module is a first magnetic sensor module and the housing further includes a second recess having the second magnetic sensor module located therein, the second magnetic sensor module including a magnetic sensor configured to detect the intensity of the magnetic field generated by the current flowing through the busbar.

6. The current sensor according to claim 5 , wherein a phase of a detection value of the first magnetic sensor is opposite to a phase of a detection value of the second magnetic sensor with regard to the intensity of the magnetic field generated by the current flowing through the busbar.

7. The current sensor according to claim 6 , wherein the calculating circuit is a subtracter.

8. The current sensor according to claim 5 , wherein a phase of a detection value of the first magnetic sensor is the same as a phase of a detection value of the second magnetic sensor with regard to the intensity of the magnetic field generated by the current flowing through the busbar.

9. The current sensor according to claim 8 , wherein the calculating circuit is an adder.

10. The current sensor according to claim 5 , wherein both the first and second magnetic sensor modules each include a circuit having a closed loop of an exciting coil.

11. The current sensor according to claim 1 , wherein:
the busbar includes first, second and third busbar portions lying in respective spaced, parallel planes with the third busbar portion being located between the first and second busbar portions, the first and third busbar portions being electrically connected in parallel, the third busbar portion being electrically connected in series with the first and second busbar portions,
the current flows through the first busbar portion in a same direction as the second busbar portion, and
the current flows through the third busbar portion in a direction opposite to the current flow through the first and second busbar portions.

12. The current sensor according to claim 11 , wherein the recess is a first recess which is located in the gap between the first and third busbar portions and the current sensor further comprises a second recess which is located in the gap between the second and third busbar portions.

13. The current sensor according to claim 12 , wherein the planes in which the first, second and third busbar portions lie are parallel to respective detection axes of the first and second magnetic sensors.

14. The current sensor according to claim 1 , wherein the housing comprises a resin material.

15. The current sensor according to claim 1 , wherein:
the busbar includes an input terminal configured to input current to the current sensor, and an output terminal configured to output current from the current sensor, and
the input terminal and the output terminal are disposed in a same plane and extend in mutually opposite directions in a direction of a detection axis of the magnetic sensor.

16. An electronic device incorporating the current sensor according to claim 1 .

17. The current sensor according to claim 1 , wherein:
the busbar includes first and second planar busbar portions lying in parallel planes with a gap interposed there between;
the recess is located in the gap; and
the magnetic sensor module has a detection axis which lies in the gap and is parallel to the planes of the busbar portions.

18. The current sensor according to claim 17 , wherein a dimension of each of the first and second busbar portions as measured in the direction of the detection axis is at least 1.5 times a dimension of the gap as measured in a direction which is orthogonal to the parallel planes in which the first and second busbar portions lie.

19. A current sensor, comprising:
a busbar integrally formed with a housing, the busbar including first and second planar busbar portions lying in respective parallel planes with a gap interposed there between, the housing having a recess located in the gap; and
a magnetic sensor module located in the recess, the magnetic sensor module including a magnetic sensor configured to detect an intensity of a magnetic field generated by a current flowing through the busbar, the magnetic sensor having a detection axis which lies in the gap and is parallel to the planes in which the busbar portions lie, a dimension of each of the first and second busbar portions as measured in the direction of the detection axis being at least 1.5 times a dimension of the gap as measured in a direction which is orthogonal to the parallel planes in which the first and second busbar portions lie.

20. The current sensor according to claim 19 , wherein:
the recess of the housing comprises a fitting structure; and
the magnetic sensor module e has an outer shape that corresponds to a shape of the fitting structure.

21. The current sensor according to claim 20 , wherein the busbar module includes an electrical device held by the housing together with the busbar in a state in which the electrical device is coupled to the busbar.

22. The current sensor according to claim 19 , wherein the magnetic sensor module further includes a calculating circuit configured to calculate a value of the current by arithmetically operating a detection value of the magnetic sensor.

23. The current sensor according to claim 22 , wherein the recess is a first recess and the magnetic sensor module is a first magnetic sensor module and the housing further includes a second recess having the second magnetic sensor module located therein, the second magnetic sensor module including a magnetic sensor configured to detect the intensity of the magnetic field generated by the current flowing through the busbar.

24. The current sensor according to claim 23 , wherein a phase of a detection value of the first magnetic sensor is opposite to a phase of a detection value of the second magnetic sensor with regard to the intensity of the magnetic field generated by the current flowing through the busbar.

25. The current sensor according to claim 24 , wherein the calculating circuit is a subtracter.

26. The current sensor according to claim 23 , wherein a phase of a detection value of the first magnetic sensor is the same as a phase of a detection value of the second magnetic sensor

Assignees

• Murata Manufacturing Co

Inventors

• Kawanami Takashi

Classifications

• G01R15/205 Primary

  using magneto-resistance devices, e.g. field plates · CPC title

• G01R19/20

  using transductors {, i.e. a magnetic core transducer the saturation of which is cyclically reversed by an AC source on the secondary side} · CPC title

• G01R15/20 Primary

  using galvano-magnetic devices, e.g. Hall-effect devices {, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices} · CPC title

• G01R15/207

  Constructional details independent of the type of device used · CPC title

• G01R15/202

  using Hall-effect devices (Hall elements in arrangements for measuring electrical power G01R21/08) · CPC title