A method of supplying direct-current (DC) power is presented herein. In the method, a first electrical signal and a second electrical signal are received. The first electrical signal alternates between a high voltage and a low voltage according to a constant duty cycle. The second electrical signal is synchronized with the first electrical signal. The first electrical signal is gated using the second electrical signal to produce a gated electrical signal with a duty cycle less than the duty cycle of the first electrical signal. The gated electrical signal is filtered to generate a DC output voltage. A difference between the generated DC output voltage and a reference DC voltage is determined. The duty cycle of the gated electrical signal is controlled by controlling the gating of the first electrical signal based on the difference.