| 摘要 |
FIELD: devices designed for switching dc circuits under load-carrying and emergency short-circuit conditions. SUBSTANCE: device has current relay, operating mechanism and its control system, and each pole is provided with two pairs of series- connected power contacts; connected in parallel with second pair of power contacts is semiconductor adapter built around transistor shorted out by opposing diode and protective circuit which is set up of series-connected varistor and capacitor shorted out by resistor. Protective circuit capacitor is shorted out by additional circuit set up of series-connected varistor and resistor. Connected in parallel with transistor is circuit of two series-connected resistors with series circuit of diode and capacitor inserted between their midpoint and control electrode of transistor; the latter capacitor is shorted out, in its turn, by resistor and auxiliary contact of device; newly introduced in device is also current transformer whose primary winding is inserted in transistor current circuit and secondary winding is connected through additional diode shorted out by resistor and through mentioned capacitor in parallel with transistor emitter and control junction. Newly introduced in device are also additional diode cumulatively connected in series with transistor, two dc voltage changers and their control system. Input terminals of first voltage changer, output terminals of second one, and diode are interconnected in series and connected through second pair of power contacts to load; input terminals of second voltage changer and of control system of both changers are connected to power supply of operating mechanism control system; input terminals of first voltage changer are connected to operating mechanism control system. EFFECT: enhanced speed of response and operating reliability. 5 cl, 1 dwg
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