A dimming system includes an alternating current input, a reference crossing detector operable to detect when a signal derived from the alternating current input crosses a reference level, a ramp signal generator operable to generate a ramp signal with a changing voltage, wherein the ramp signal generator is operable to restart the ramp signal based on an output of the reference crossing detector, a switch operable to control a current derived from the alternating current input to a load output, a switch driver operable to control the switch based at least in part on the ramp signal, and a difference amplifier operable to generate a difference between the ramp signal and an input from a light sensor, wherein the switch driver is operable to control the switch based at least in part on the difference.