A method of surge reduction in the switching regulator

Abstract

When the switching regulator is used for the supply of the color T.V. receiver, the following two conditions are desired to be satisfied. (1) The switching operations should be completed within the retrace interval of horizontal scanning. (2) The output voltage is close to the input voltage value. To realize a regulator satisfying both of these two conditions, a reactor with two windings should be used. In this case, turn ration of windings differs far from unity. Hence a surge voltage due to leakage inductance appears across the transistor. The amount of the surge may be great enough to cause a break down in the transistor. We propose in this paper a method of cascade connection to give a solution to the problem of switching surge. The key point of the surge reduction is to make use of a cascade connection of the switching regulator with reactors of single winding. The efficiency, the voltage rating of the transistor and the regulation range are discussed on typical three kinds of circuit.