A flyback controller may receive a chopped and rectified AC voltage from a dimmer control, each cycle of which may have a controllable off period that is substantially attenuated but not always zero due to leakage of the dimmer control, and a controllable on period that substantially tracks the AC voltage. The flyback controller may include a control circuit configured to generate a switching signal based on the signal from the dimmer input. The switching signal may controllably oscillate between its on and off states during the on periods of the chopped and rectified AC voltage so as to controllably regulate current that is delivered by a secondary winding of a transformer in a flyback converter. The switching signal may be in the on state during the off periods of the chopped and rectified AC voltage, thereby preventing a voltage build up from the dimmer control leakage.