Patent ID: 6469917
Filing Date: 2002-10-22
Classification: H02M,Y02B,Y02P

Abstract:
A power factor correction apparatus, for a switching power supply fed by an array of rectifying diodes and consisting of at least an input inductor, a contact of which is connected in series with a contact of said array, and of a power switch connected between the other contact of said array and the other contact of said input inductor, comprising:a) circuitry for identifying, in each cycle determined by the switching frequency of said power supply, whenever the instantaneous value of the current through said inductor reaches a minimal value; b) circuitry for switching said power switch to its conducting state in response to said minimal current through said inductor; c) circuitry for reflecting the current flowing through said inductor by a measurable or simulated parameter; and d) circuitry for providing indication, in each cycle, by using said parameter, said indication being related to the timing until the peak value of said current, that corresponds to a specific load, has been essentially reached, or to the time from the moment that said current reaches said minimal value until said timing, and for switching said power switch to its non-conducting state in response to said indication.