An AC-to-DC power converter that is capable of generating a regulated, isolated DC voltage output from a power factor corrected AC voltage input with improved efficiency. The AC-to-DC power converter is a two-stage power converter including a PFC stage connected in series to a power conversion stage. The PFC stage performs power factor correction using a zero current switching technique, and the power conversion stage includes a zero voltage switched half-bridge converter. The power conversion stage includes a transformer for providing the isolated DC voltage output. The AC-to-DC power converter includes a single feedback control loop for transferring error information from the DC voltage output to the PFC stage, thereby obtaining regulation of the DC voltage output.
A half bridge converter having a pulse width control unit, a level regulating unit, a half bridge switch unit, an electricity converting unit and a feedback unit is disclosed. The level regulating unit receives a first DC electricity and boosting the first DC electricity to a working voltage level for forming a working electricity. The pulse width control unit produces a conduction cycle signal for controlling the half bridge switch unit to switch the working electricity to a conduction timing of the electricity converting unit, so that the electricity converting unit converts the working electricity to output a second DC electricity. The feedback unit draws a feedback signal from the second DC electricity to send to the level regulating unit for altering the voltage of the working electricity, so as to adjust the output of the electricity converting unit, thereby achieving voltage regulation.
