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Title:
【発明の名称】2アウトオブ4回路
Document Type and Number:
Japanese Patent JPH0668689
Kind Code:
B2
Abstract:
PURPOSE:To remarkably curtail a current detecting means by providing total four pieces of current detecting means by one piece each of first and second contacts, and fifth and sixth contacts, among the first-the eighth contacts, so that the contact can be tested. CONSTITUTION:Signal processors 17-20 input signals from sensors A1-N1, A2-N2, A3-N3 and A4-N4, respectively and bring them to an arithmetic processing, and output driving signals (a)-(d) to an output circuit 16 in case its result exceeds a prescribed value. The circuit 16 is provided with four pieces of current detecting means 12-15 for detecting a current flowing to a contact. These current detecting means 12-15 are formed by a transformer, etc. A diagnostic device 25 outputs a test signal 26 to switches 21-24 in order to set the signals (a)-(d) to a prescribed variation value. By checking a current detection result signal 27 being an output result of the current detecting means 12-15 in this case, the soundness of contacts 2-9 is evaluated.

Inventors:
Arita Setsuo
Application Number:
JP15448287A
Publication Date:
August 31, 1994
Filing Date:
June 23, 1987
Export Citation:
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Assignee:
株式会社日立製作所
International Classes:
G21C7/36; G05B7/02; G05B9/03; H03K19/23; (IPC1-7): G05B9/03; G05B7/02; G21C7/36; H03K19/23
Domestic Patent References:
JP63140305A
Attorney, Agent or Firm:
Masami Akimoto