US Patent 7649327 System and method for selectively dimming an LED

Embodiments of the present disclosure include an LED ballast circuit for dimming one or more LEDs using a phase controlled dimmer switch. The LED ballast circuit has a power conditioning unit which includes a substantially fixed duty cycle clock for outputting a clock cycle and a transformer configured to store energy and discharge a substantial portion of the stored energy once per clock cycle in order to power one or more LEDs. The LED ballast circuit and load collectively behave like a resistor.