DEVICE FOR CONTROL OF THYRISTOR SWITCH Russian patent published in 1994 - IPC

FIELD: telephone devices. SUBSTANCE: third output of thyristor switch, self-test unit and 2AND-NOT gate are introduced to accomplish the goal of invention. Device has control unit which has two transistors 2, 3, four resistors 4, 5, 6 and 7, thyristor switch 8 made in transistor. It has three transistors 9, 12, and 13 and two resistors 10 and 11. In addition device has control unit 16 having two transistors 17 and 19, three diodes 20, 23 and 24 and three resistors 18, 21 and 22, 2AND-NOT gate having two-emitter transistor 27 and two transistors 30 and 33, three resistors 26, 31 and 32. EFFECT: increased reliability. 1 dwg