Power supply with power factor correction

摘要

This disclosure relates to a power supply circuit for converting AC energy from an AC source to DC energy for powering a load. The circuit comprises first and second circuit lines and a full wave rectifier connectable to the AC source and to the circuit lines for providing a rectified input voltage on the circuit lines. An inductor is connected in one of the circuit lines and an output capacitor is connected across the circuit lines between the inductor and the load. A control switch including two power terminals and a control terminal has the two power terminals connected across the circuit lines between the inductor and the output capacitor. A sensor responsive to current flow through the inductor provides a current representative signal. A relatively high fixed frequency oscillator closes the control switch in each cycle thereof. A circuit responsive to a comparison of the input and output voltages with the current representative signal opens the control switch when the current representative signal reaches a preset value based on the input plus the output voltages.