Title:
VOLTAGE DETECTING DEVICE
Document Type and Number:
Japanese Patent JP3304597
Kind Code:
B2
Abstract:
PURPOSE: To secure insulation between circuits, and restrain generation of heat by making light from a light emitting device incident on a liquid crystal display on which voltage to be detected is impressed, and receiving transmitted light by a light receiving device.
CONSTITUTION: Voltage to be detected is divided by an electric 7 current restricting resistor 4 and a Zener diode 5, and is impressed on a liquid crystal display 1, and the device 1 is turned on. A light emitting part 9 emits pulse light having wave lengths (λ1 and λ2), and makes it incident on the device 1 and an optical filter 6 through optical fiber 10. The light incident on the device 1 in an ON condition passes as it is, and in the light incident on the filter 6, only light having a wave length (λ1) passes, and both and are made incident on a light receiving unit 15 through optical fiber 19. The output signal is separated into pulses having wave lengths (λ1 and λ2) by a separator 16, and the pulses having (λ2) are counted by a detector 17, and when they exceed a prescribed value, it is judged as the voltage to be detected exists. When the pulses having (λ1) are counted by a detector 18, abnormality of the light emitting part 9, the optical fibers 10 and 19 or the like can be detected.
Inventors:
Hideto Ohki
Application Number:
JP4208694A
Publication Date:
July 22, 2002
Filing Date:
March 14, 1994
Export Citation:
Assignee:
Nissin Electric Co., Ltd.
International Classes:
G01R31/02; G01R15/22; G01R15/24; G01R19/00; G01R19/155; (IPC1-7): G01R19/155; G01R15/24; G01R19/00; G01R31/02
Domestic Patent References:
| JP4198763A | ||||
| JP2198365A | ||||
| JP59122959A |
Attorney, Agent or Firm:
Akio Miyai
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