Title:
TEST CIRCUIT FOR SAFETY PROTECTION SYSTEM
Document Type and Number:
Japanese Patent JPS5829013
Kind Code:
A
Abstract:
PURPOSE:To decrease the danger of plant stop due to erroneous trip, by providing a switch for the test of by-pass state of a specific channel and of each vice table unit and processing the output of the switch selectively. CONSTITUTION:When a by-pass command switch (SW)1 is depressed, ''1'' is outputted, a channel 1 is set to the test mode and the remaining channels are in a normal operating state. Thus, the output of non-trip by-pass (NTB)2-4 of channels 2-4 is at ''0'', this signal is selected at gates G1-G3 and ''1'' is inputted to a gate G4. When a test SW6 provided to each vice table is depressed, an output goes to ''1'' and inverted at an inverter G5, then an output V01 of an AND gate G8 goes to zero, i.e., the non-trip state is obtained. In this test state, the operation of 2-out-of-4 is made. When a channel 1 is tested during the test of a channel 2, an output of an NTB2 goes to ''1'' and the output of the by-pass 8 of the channel 1 and the NTB9 goes to ''1'' and the output of the trip by-pass TB5 goes to ''1'' and the output V01 goes to ''1'' with the SW6 depressed, that is, the trip signal is obtained.
Inventors:
OKAMOTO TETSUO
KOBAYASHI HIDEO
TAKAMORI HISAHARU
KOBAYASHI HIDEO
TAKAMORI HISAHARU
Application Number:
JP12710281A
Publication Date:
February 21, 1983
Filing Date:
August 13, 1981
Export Citation:
Assignee:
YOKOGAWA ELECTRIC WORKS LTD
International Classes:
G21C17/00; G05B23/02; (IPC1-7): G21C17/00
Attorney, Agent or Firm:
Shinsuke Ozawa