CONTROL CIRCUIT Russian patent published in 2000 - IPC

FIELD: safety of duplicated hardware of systems of railway automatics. SUBSTANCE: given control circuit tests coincidence of dynamic information signals in test points of two similar sets of equipment to be diagnosed which operate in step. In this case logic function AND is realized. Control circuit incorporates following units: two AND gates, three inverters, two diode bridges, two optrons, three transistors, optoelectronic switch-inverter NOR with resistive input isolation, NAND gate, six capacitors, twelve resistors, source of +5 V power supply. If duplicated system is serviceable then signal "logic one" is formed across output of control circuit that has same frequency as signal across input of circuit testing U_in. If hardware of duplicated system is out of order then signal across output of control circuit corresponds to logic zero, that is to lack of frequency. EFFECT: enhanced efficiency of control circuit testing reliability of duplicated hardware. 1 dwg