Title:
OVERCURRENT DETECTION CIRCUIT
Document Type and Number:
Japanese Patent JP3437122
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To surely detect only overcurrents by a simple circuit configuration without erroneously detecting a normal operation as an overcurrent with respect to loads such as to produce a rush current at the start of the supply of the power or to cause the level of current to rise as a part of normal operation during power the supply of like a motor lock current.
SOLUTION: A current detection circuit 10 outputs from an output part 11 a proportional current Is proportion to a load current IL flowing through a shunt resistance 2. An integration circuit 20 is made up by connecting a resistance R1 between the output part 11 of the current detection circuit 10 and the earth, and connecting the resistance R1 in parallel with a series circuit comprising a low resistance R2 and a capacitor C1. A comparator 40 compares an output voltage V0 from the integration circuit 20 with a reference voltage VR from a reference voltage generating circuit 30. When the output voltage Vr- exceeds the reference voltage V-, the comparator 40 outputs a low-level voltage signal as an overcurrent signal.
Inventors:
Takashi Hoshino
Application Number:
JP17064099A
Publication Date:
August 18, 2003
Filing Date:
June 17, 1999
Export Citation:
Assignee:
Auto Network Technology Laboratory Co., Ltd.
SUMITOMO WIRING SYSTEMS,LTD.
Sumitomo Electric Industries, Ltd.
SUMITOMO WIRING SYSTEMS,LTD.
Sumitomo Electric Industries, Ltd.
International Classes:
G01R31/02; G01R19/165; (IPC1-7): G01R19/165; G01R31/02
Domestic Patent References:
| JP3265417A | ||||
| JP9308079A | ||||
| JP9318680A | ||||
| JP55101059A | ||||
| JP61198066A |
Attorney, Agent or Firm:
Etsushi Kotani (2 outside)
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