Patent ID: 7446486
Filing Date: 2008-11-04
Classification: H02M,Y10S

Abstract:
1. A method of generating a power supply voltage in a two wire dimmer having a phase cut switching device adapted to be coupled between a hot side of an AC line and a lamp load for providing power to the lamp load, the method comprising the steps of: receiving an AC waveform from the hot side of the AC line; charging a charge storage capacitor from the AC line through a charge storage switching device during regions of the AC waveform when the phase cut switching device is substantially off to generate the power supply voltage across the charge storage capacitor; generating a control voltage across a high voltage drive source capacitor; providing the control voltage to a control electrode of the charge storage switching device to drive the charge storage switching device on in a saturated region of operation when a magnitude of the AC waveform is less than a predetermined level; and turning the charge storage switching device off when the AC waveform is above the predetermined level; and providing the power supply voltage across the charge storage capacitor as an output voltage.