ARCLESS-SWITCHING DC CONTACTOR Russian patent published in 1996 - IPC

FIELD: electrical engineering. SUBSTANCE: contactor has main contact 3 shorted out by main thyristor 1 and backward diode 2. Forced switching unit affording turn-off of thyristor 1 upon opening of main contact 3 has switching thyristor 5, capacitor 6, and choke 7. Capacitor 6 is charged by means of charging circuit that has choke 8 and thyristor 9. Charging circuit is connected through contacts 18 mechanically coupled with contacts 19 that function to connect coil 20 of electromagnet to power supply 4. Charging process and associated turn-on of main thyristor 1 are completed before main contact 3 starts opening. Upon completion of arcless opening of main contact 3, contacts 15 of limit switch close with the result that thyristor 5 is turned on and forced switching unit 5 is energized; then thyristor 1 stops passing current and load 21 is disconnected from power supply 4. EFFECT: improved design. 1 dwg