THREE-PHASE SWITCH Russian patent published in 2003 - IPC

FIELD: pulse engineering; load switching. SUBSTANCE: first leads of thyristor pairs 1 and 2, 3 and 4, 5 and 6 are connected respectively to anodes of first diodes 8, 9, 10 and to cathodes of third diodes 14, 15, 16; they are also connected through load 26 to respective phases of supply mains; second leads of thyristor pairs 1 and 2, 3 and 4, 5 and 6 are interconnected; control switch 7 is connected through its first lead to cathodes of first diodes 8, 9, 10 and through breaking contact 24 of responding element 23, to first leads of resistors 18, 19, 20 and to anode of light-emitting diode of photon-coupled thyristor 22 whose cathode is connected through current-limiting resistor 21 to anodes of third diodes 14, 15, 16; second leads of resistors 18, 19, 120 are connected to gate electrodes of thyristors 2, 4, 6 and to anodes of second diodes 11, 12, 13 whose cathodes are connected to gate electrodes of thyristors 1,3, 5, respectively; responding element 23 shorted out in backward direction by fourth diode 17 is connected by means of its lead to minus terminal 28 of dc voltage supply, its other lead being connected through photon-coupled thyristor of optocoupler 23 to plus terminal 27 of mentioned voltage supply. EFFECT: enhanced reliability and service life. 1 dwg