Title:
ABNORMALITY DETECTOR FOR POLYPHASE PULSE SIGNAL STRING
Document Type and Number:
Japanese Patent JPS54104277
Kind Code:
A
Abstract:
PURPOSE:To detect the long-period abnormality of a polyphase pulse signal string, by outputting an abnormality signal when the smoothing output of the logical sum classified by polyphase pulse signals becomes less than a set voltage. CONSTITUTION:Ignition pulse signal strings S1, S3 and S5 applied to thyristors SCR1, SCR3 and SCR5 are insulated electrically and then detected by pulse detectors 101, 103 and 105 before being waveform-shaped by waveform shaping circuits 111, 113 and 115. Then, their outputs are converted by monostable multivibrators into pulse signal strings of constant width and synthesized by OR circuit OR; the output of OR is converted by smoothing circuit 13 into a DC voltage signal, which is compared with the set voltage from voltage setting circuit 14 by comparator circuit 15. Then, when the signal falls down to the value of the set voltage, the abnormality signal is outputted via latch circuit 16. Since the smoothing circuit is used in this way, a practical abnormality detector can be obtained which detects no extremely-short-period abnormality.
Inventors:
ISHIBASHI AKIRA
HIROSE HIROSHI
NOMOTO SHIGERU
HIROSE HIROSHI
NOMOTO SHIGERU
Application Number:
JP1043978A
Publication Date:
August 16, 1979
Filing Date:
February 03, 1978
Export Citation:
Assignee:
HITACHI LTD
International Classes:
H02P27/02; H02M1/00; H02M1/08; (IPC1-7): H02M1/08; H02P5/40
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