Bridgeless power factor correction circuit with improved critical mode (CRM) operation

摘要

A power factor correction circuit includes: the first series circuit consisting of the first rectifier element and the first switching element; the second series circuit consisting of the second rectifier element and the second switching element; the first/second reactors; and the first/second current detectors. The first/second current detectors have each the first/second transformers, both primary parts of which consist of the first/second reactors. The first and the second switching elements are controllable based on the first output signal according to the reactor current from the secondary side of the first transformer and the second output signal according to the reactor current from the secondary side of the second transformer so as to apply a desired DC voltage to the load circuit.