US 4,283,759 A · Switching regulator

Abstract

A switching regulator which is designed so that a negative feedback is applied to the base of a transistor constituting an oscillator adapted for chopping a DC voltage, only during a period of time which is required to effect pulse width control when the transistor is switched from conduction to non-conduction. A control circuit may also be provided which is arranged to compare the output of a current detecting circuit for detecting a current proportional to a current for driving a transformer with the output of an error voltage amplifier for amplifying an output resulting from comparison of a rectified version of the AC output of the transformer with a reference voltage. The foregoing control circuit is also arranged so that when the output of the current detecting circuit exceeds the output of the error voltage amplifier, a trigger signal is imparted to cause the oscillator to be changed from the on state to the off state.

Claims7

Dependent claims

A switching regulator comprising a relaxation oscillator circuit for chopping a DC voltage supplied from an input power source to thereby drive a transformer;

a rectifier circuit for rectifying the AC output of said transformer;
a feedback circuit for comparing the rectified output voltage derived from said rectifier circuit with a reference voltage and applying a negative feedback to the base of the transistor or said oscillator circuit in accordance with the deviation of said rectified output voltage from said reference voltage;
and means for permitting said negative feedback to be applied only during that period of the relaxation oscillation cyclic periods which is required to effect pulse width control when said transistor is switched from conduction to non-conduction.

Dependencies are inferred from the claim text.

Switching regulator

Life of this patent

Switching regulator

Life of this patent

Abstract

Claims7