QUASIRESONANT DC VOLTAGE CHANGER INCORPORATING ZERO-VOLTAGE CHANGE-OVER PROVISION Russian patent published in 1998 - IPC

FIELD: converter engineering; power supplies for DC voltage conversion; telecommunication equipment. SUBSTANCE: converter has power transformer whose primary winding is connected through power transistor switch and first resistor to input leads which are connected in parallel with first capacitor and with circuit set up of series-connected second resistor, second capacitor, and second winding of power transformer whose secondary winding is connected through first diode and filter to output leads; control input of power transistor switch is connected to second input lead through first control transistor switch connected in parallel opposition to second diode; control input of first control transistor switch is connected through third resistor to input of power transistor switch; it also has fourth resistor whose first lead is connected to point of connection of second resistor and second capacitor; newly introduced in voltage changer are second control transistor switch, first and second choke coils, third and fourth diodes, third winding of power transformer, and third capacitor. EFFECT: simplified control circuit arrangement and improved reliability. 2 dwg