D C SWITCH ( VARIANTS ) Russian patent published in 2002 - IPC

FIELD: switching of D C circuits. SUBSTANCE: D C switch has first and second contactors, voltage pickup, backward diode, capacitor and first resistor. It is inserted with first and second electron keys, second diode, second resistor and current pickup and command device is fitted with first and second additional outputs and two controlling inputs connected correspondingly to controlling inputs of electron keys and to outputs of current and voltage pickups. Such arrangement secures operational supply condition of load switching on under which both contactors and first electron key are cut in and operational supply condition of load switching off under which second electron key and first contactor are cut in and then second electron key and second contactor are cut out. EFFECT: raised speed of cut-out and reduced switching surge. 6 cl, 3 dwg