Methods and apparatus for high power factor controlled power delivery using a single switching stage per load

Abstract From the Canadian patent

Methods and apparatus for high power factor power transfer to a load using a single switching stage. In exemplary implementations a controllable variable , power may be delivered to a load using a single switching stage while maintaining high power factor, in some cases without requiring any feedback information relating to the load conditions (i.e. without monitoring load voltage and/or current) to control normal switching operations in the single switching stage, and without requiring regulation of load voltage and/or load current. In one example, a single stage high power factor driver is used to control power delivery to an LED-based light source.