Abstract: An electromagnetic interference reduction circuit incorporated into a pulse width modulator in a power factor corrector circuit, and which serves continuously to vary the operating frequency of the width modulated output of the pulse width modulator so that the fundamental component of said output is spread over a relatively wide bandwidth. The frequency of the width modulated output varies continuously in direct proportion to the voltage from a rectified alternating current sine wave voltage source in order to spread the electromagnetic interference in the circuit over a wide bandwidth.