Regulation and stabilization in a switching power supply

Claim 1

A regulating device for producing a regulated D.C. voltage comprising: a pair of input terminals for receiving an input signal; input means coupled to the input terminals for producing a first D.C. signal in response to the input signal; switching means coupled to the first input means for producing primary pulses at a predetermined frequency by switching the first D.C. signal on and off; transformer means coupled to the switching means for producing secondary pulses responsive to the primary pulses; output rectifying means coupled to the transformer means for rectifying the secondary pulses; first output filtering means coupled to the output rectifying means for filtering the rectified secondary pulses, thereby producing an output D.C. voltage; first comparison means coupled to the first output filtering means for comparing a D.C voltage sensed at the output of the first output filtering means with a first reference voltage, and producing a trigger signal when the level of the sensed voltage differs from the level of the first reference voltage by a predetermined amount, said comparison means operating to compare the voltages at each cycle of operation; active circuit means for producing a stabilizing voltage and summing the stabilizing voltage with one of the sensed voltage and the first reference voltage before comparison of the sensed voltage and the first reference voltage in the comparison means; pulse width modulating means coupled to the first comparison means and to the switching means for varying the width of the primary pulses produced by the switching means, in response to the trigger signal frOm the first comparison means; and oscillating means coupled to the pulse width modulating means for establishing the predetermined frequency of the primary pulses produced by the switching means.