Patent ID: 9307593
Filing Date: 2016-04-05
CPC Classification: H05B,Y02B

Claim Text:
1. A light-emitting diode (LED) lamp, comprising: an LED string including one or more LEDs; a rectifier circuit configured to receive an AC input voltage and to generate a rectified voltage corresponding to the AC input voltage, the rectified voltage is a phase-cut AC input voltage indicating a dimming level; a bleeder circuit coupled to the rectifier circuit and configured to turn on to provide a bleeder current at a first current level responsive to the AC input voltage less than a first threshold voltage and to reduce the bleeder current to a second current level responsive to the AC input voltage exceeding a second threshold voltage; and an LED driver circuit configured to switch on or off a power stage switch according to a duty cycle based on the rectified voltage, to regulate a driving current through the LED string.