HIGH POWER FACTOR LED-BASED LIGHTING APPARATUS AND METHODS

摘要

Power control methods and apparatus in which a switching power supply provides power factor correction and an output voltage to a load via control of a single switch, without requiring any feedback information associated with the load. The single switch may be controlled without monitoring either the output voltage across the load or a current drawn by the load, and/or without regulating either the output voltage across the load or the current drawn by the load. The RMS value of an A.C. input voltage to the switching power supply may be varied via a conventional A.C. dimmer (e.g., using either a voltage amplitude or duty cycle control technique) to in turn control the output voltage. The switching power supply may comprise a flyback converter configuration, a buck converter configuration, or a boost converter configuration, and the load may comprise an LED-based light source.