Method for actuating a switching transistor operating as a setting member in a DC/DC converter

摘要

A dc/dc converter for controlling the current through a load which comprises a switching transistor having its emitter-collector circuit coupled between an input voltage source and the load. A control transformer having first, second and third electromagnetically coupled windings is also provided, the second winding of the transformer being electrically connected between the base and emitter of the switching transistor. A control switching logic circuit selectively generates pulses for determining the beginning and the end of the conducting period of the switching transistor, and a control circuit coupled to the logic circuit selectively short circuits the third winding thereby reducing the voltage across the second winding and driving the switching transistor into its non-conducting state. A charging control circuit selectively energizes the first winding from the input voltage source and disconnects this winding from the source when sufficient energy has been stored in the core of the transformer to actuate the switching transistor.