Patent ID: 8760072
Filing Date: 2014-06-24
Classification: H05B,Y02B

Abstract:
1. A method of controlling a power supply for light emitting diode (LED) module in a roadway fixture, the method comprising: performing electro-magnetic interference (EMI) filtering of an incoming alternating current (AC) current; performing AC to direct current (DC) rectification of the AC current; stepping down the rectified DC current based upon a power correction factor (PFC) value; providing the stepped down DC current to the LED module; measuring a current through the LED module; determining the PFC value based upon at least the measured current through the LED module; feeding-back the determined PFC value to control the stepped down DC current; and determining a turn-on cycle used in determining an age of the LED module for a ramp-over-time current mode to provide an increasing current to the LED module to maintain illumination output over time by adjusting the PFC value.