In an electric power switching apparatus a control circuit generates a
switching control signal, for controlling successive current switching
operations, as a of succession of pulse period patterns with each pulse
period pattern made up of one or more successive pulses each having an
identical pulse period, and with successive pulse period patterns
constituting the control signal having respectively different values of
pulse period. The noise power of high-frequency components resulting from
the current switching is thereby dispersed along the frequency spectrum,
reducing resultant radio noise interference.