Patent ID: 6370039
Filing Date: 2002-04-09
Classification: H02M

Abstract:
A power supply, comprising;a voltage regulator responsive to an error signal for regulating a DC internal voltage output; and a DC/AC switching power converter including a transformer having a primary winding coupled to the DC internal voltage output and one or more power switches; a control circuit driving the one or more power switches at a constant duty cycle such that an alternating current having a constant duty cycle flows through the primary winding; and an error amplifier having an input coupled to a current sensor, the current sensor sensing a voltage proportional to the current through the primary winding, the error amplifier having another input coupled to a reference voltage proportional to a maximum expected voltage loss on a load coupled to a secondary winding of the transformer, the error amplifier outputting a control signal proportional to the difference between the reference voltage and the voltage sensed by the current sensor; wherein the error signal is based upon the control signal and a signal proportional to the internal voltage output.