Drive circuit for flicker-free led lighting having high power factor

Abstract

A drive circuit for flicker-free LED lighting having a high power factor, the circuit comprising a start-up circuit, a controller, a transformer T1, a first current switch, and a second current switch. The transformer T1 comprises a main primary winding Np1, a primary winding Np2, a primary winding Na, and a secondary winding Ns. The main primary winding Np1 and the primary winding Np2 are in-phase, the primary winding Na and the secondary winding Ns are in-phase, and phases of the main primary winding Np1 and the secondary winding Ns are inverted. The start-up circuit and the transformer T1 are connected to an input terminal Vin. The start-up circuit, the first current switch, and the second current switch are connected to the controller. The controller controls, by means of controlling the first current switch, and the second current switch to turn on or off, an output current of the secondary winding Ns of the transformer T1. The drive power supply circuit for LED lighting having a high power factor reduces ripples in an output current, thereby realizing advantages of a high power factor, being flicker-free, and having a low cost, etc., for LED lighting.

Dependencies are inferred from the claim text.