Patent ID: 8310171
Filing Date: 2012-11-13
Classification: H05B

Abstract:
1. A current driver circuit for at least one light emitting diode (LED) comprising: an input section adapted to receive a truncated power waveform generated by a variable dimmer circuit, the truncated power waveform having a positive pulse portion and a negative pulse portion, a duty cycle of which is proportional to a desired dimming level; a rectifier section for rectifying the input truncated power waveform to a plurality of positive pulses; a current switching regulator adapted to provide a constant current to the at least one LED; and a controller coupled to the rectifier section and adapted to determine a level of each of the plurality of positive pulses, wherein if the level is below a first predetermined threshold, the current switching regulator is turned off by the controller and, if the level is a above a second predetermined threshold, the current switching regulator is turned on by the controller so as to pulse modulate the constant current to the at least one LED to maintain the desired dimming level of the at least one LED.