Title:
MAGNETIC-BALANCE CURRENT SENSOR
Document Type and Number:
WIPO Patent Application WO/2012/026255
Kind Code:
A1
Abstract:
A magnetic-balance current sensor that allows miniaturization, is easier to install, and exhibits decreased hysteresis and increased measurement precision. This magnetic-balance current sensor is provided with: a magnetism-detection bridge circuit, the output of which changes in accordance with an induced magnetic field from a wire through which a current being measured flows; a magnetic-field attenuation unit (30) that attenuates the induced magnetic field applied to a magnetoresistive effect element in the magnetism-detection bridge circuit; and a feedback coil (122) that generates a cancelling magnetic field that cancels out the induced magnetic field on the basis of the output from the magnetism-detection bridge circuit. When an equilibrium state in which said cancelling magnetic field and the induced magnetic field cancel each other out is reached, a current proportional to the current being measured flows through the feedback coil. The feedback coil (122) is provided such that the direction of the cancelling magnetic field applied to the magnetic-field attenuation unit (30) is roughly opposite the direction of the induced magnetic field applied to the magnetic-field attenuation unit (30).
Inventors:
HEBIGUCHI HIROYUKI (JP)
Application Number:
PCT/JP2011/066803
Publication Date:
March 01, 2012
Filing Date:
July 25, 2011
Export Citation:
Assignee:
ALPS GREEN DEVICES CO LTD (JP)
HEBIGUCHI HIROYUKI (JP)
HEBIGUCHI HIROYUKI (JP)
International Classes:
G01R15/18
Foreign References:
| JP2004132790A | 2004-04-30 | |||
| JP2000516714A | 2000-12-12 |
Attorney, Agent or Firm:
AOKI, Hiroyoshi et al. (JP)
Hiroyoshi Aoki (JP)
Hiroyoshi Aoki (JP)
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Claims: