FIELD: electrical engineering; transistorized dc switching devices. SUBSTANCE: device that may be used, for instance, in secondary power supplies to control switches with electrically isolated power and control circuits to ensure high-speed change-over dispensing with booster current from external unipolar control signal source under conditions of wide range of pulse-to-space ratio variations has matching transformer whose first winding is inserted in circuit set up of dc voltage source and power junction of current-controlled amplifying transistor one of whose electrodes is connected to control input of device through resistor and also is connected to second common electrode of amplifying transistor control input through first booster capacitor, first diode, and positive feedback winding. Device also has first and second cut-off transistors, backward diodes, second and output windings. Novelty is introduction of second cut-off transistor and its new connections with known components to ensure normal operation of device at low pulse-to-space ratios of control signal. EFFECT: enhanced efficiency of output current utilization, reduced size and mass, enlarged functional capabilities of device. 5 cl, 2 dwg
