Abstract: A dimmer for controlling AC power to a lighting load provides a leading power factor by initiating conduction through an electronic switch at each zero crossing of the line current. The dimmer delivers current to the lighting load in a sequence of pulses where each pulse corresponds to a portion of one AC half wave. A variable resistance that alters a voltage signal delivered to an integrated circuit permits the user to determine the duration of each pulse and thus vary the power delivered to the lighting load. The dimmer is provided with over current protection.