Patent ID: 8294379
Filing Date: 2012-10-23
Classification: H05B,Y02B

Abstract:
1. A dimmable light-emitting diode (LED) lamp, comprising: a bridge rectifier, receiving a source alternating current (AC) voltage through a wall switch and providing a rectified direct current (DC) voltage; a toggle detector, monitoring a toggle action of the wall switch; a sustain voltage supply circuit, providing a sustain voltage according to a bias AC voltage, wherein the bias AC voltage is a induced voltage and provided only when the wall switch is turned on; a counter, receiving the sustain voltage for operation, storing and providing an counting value that changes when the toggle detector detects the toggle action of the wall switch; an LED light source; an LED lighting driver, converting the rectified DC voltage to a constant current to drive the LED light source and providing multi-level dimming to the LED light source according to the counting value, wherein the LED lighting driver comprises: a bias voltage supply circuit, providing the bias AC voltage and a bias DC voltage, rectifying the bias AC voltage and filters out ripples in the rectified bias AC voltage and, providing a result of the filtering as the bias DC voltage to be received by the LED lighting driver for operation, and comprises a bias winding electro-magnetically coupled to the inductor via sharing a common magnetic core, the bias winding provides the bias AC voltage by receiving power from the inductor when the MOSFET is switching.