Drive circuit for light emitting diode array based on sepic or cuk topology

摘要

Features of the invention are related to drive circuits that provide both power factor correction and voltage conversion in a single circuit and in some instances drive an LED array. This single stage converter uses a SEPIC or Cuk topology and can operate LED arrays that have DC voltages above or below the AC line voltage. An output side filter and bulk energy storage device is placed at the output of the circuit. Bulk energy storage can be provided by an inductor, a capacitor, or a combination of an inductor and a capacitor. The output side filtering can be provided by a capacitor or a capacitor and an inductor. The circuit also includes a switch and a switch control device for controlling the switch to provide power factor correction.

主权项

1. A drive circuit, comprising:
a first load connection point and a second load connection point for connecting a load to an output of the drive circuit; an output side filter and bulk energy storage device, wherein the output side filter and bulk energy storage device is connected to the first load connection point, to the second load connection point, and to a sub-circuit based on a SEPIC topology, wherein the sub-circuit includes a capacitor, a free wheeling diode, a first inductor, a second inductor, and a switch; the sub-circuit, wherein the sub-circuit is connected to an input of the drive circuit, to the output side filter and bulk energy storage device, and to the first load connection point; and a control device for controlling the switch to provide power factor correction, wherein the circuit provides both power factor correction and load regulation using the switch, wherein the output side filter and bulk energy storage device comprises a second capacitor and a third inductor and a first terminal of the second capacitor is connected to the first load connection point and a second terminal of the second capacitor is connected to the cathode of the free wheeling diode and a first terminal of the third inductor, and a second terminal of the third inductor is connected to the second load connection point and the first terminal of the third inductor is connected to the cathode of the free wheeling diode and to the second terminal of the second capacitor, and wherein the input of the drive circuit is operable for connection to an output of a bridge rectifier.