D C VOLTAGE STEP-UP CIRCUIT ARRANGEMENT Russian patent published in 1995 - IPC

FIELD: electrical engineering. SUBSTANCE: d.c. voltage step-up circuit has pulse generator built up of transistors T1,T2, resisters R1,R2,R4, capacitor C1, and choke coil DR, isolating diode D1, storage capacitor C2, and negative feedback circuit incorporating resistive voltage divider built around resistors R5,R6, voltage regulator diode D2, and d.c. amplifier that has transistors T2,T4 and resistor R3. Emitter of transistor T1 is connected to positive terminal of power supply and its collector, to negative terminal of power supply through resistor R2; emitter of transistor T2 is connected to negative terminal of power supply and base, to collector of transistor T1, and collector of T2 is connected to base of T1 via series-connected capacitor C1 and resistor R4 and to positive terminal of power supply, via series-connected diode D1 connected in forward direction and capacitor C2. Resistive voltage divider is connected in parallel with capacitor C2; cathode of voltage regulator diode D2 is connected to resistive voltage divider and its cathode, to base of transistor T3 whose emitter is connected to negative terminal of power supply and collector, to its positive terminal via resistor R3. Emitter of transistor T4 is connected to power supply negative terminal and collector, to base of transistor T1 through resistor R1; base of transistor T4 is connected to collector of transistor T3. Voltage is raised due to self-induction voltage built up in choke coil DR when transistor T2 is cut off. Output voltage is regulated by controlling length of ON-state of output transistor T2 that determines amount of energy stored by choke coil DR. Output transistor T2 can operate in switch mode. ON-state of output transistor is controlled by signal generated by negative feedback circuit. EFFECT: improved economic efficiency of circuit. 2 dwg