An electric power supply circuit includes a diode bridge circuit (12) for rectifying an alternating current, a switching element (S) for causing a short-circuit for output power of the diode bridge circuit (12), and a PAM control section (15) for causing the switching element (S) to perform switching with a predetermined timing so that a waveform of an input current approximates to a sine wave. The PAM control section (15) outputs ON/OFF pulses so that five pulses are output for each zero-cross point and one of the five pulses located in center extends over the zero-cross point at any time.
