Patent ID: 7548438
Filing Date: 2009-06-16
Classification: H02M,Y02B

Abstract:
1. A method of shaping input current to a boost-type AC to DC power converter based upon a first reference shape of peak current values and a second reference shape of peak off-time values, the method comprising: receiving an input voltage signal to the power converter; determining a count corresponding to a phase of the input voltage signal, the count corresponding to one of at least a first range, a second range, and a third range of the phase of the input voltage signal; determining turn-on timings and turn-off timings of a switch in the boost-type power converter based upon one or more operation modes, at least one of the operation modes being a peak current switching mode that determines the turn-off timings of the switch so as to keep the switch on until a current through the switch reaches the peak current value corresponding to the determined count at which time the switch is turned off, and at least another one of the operation modes being a shaped off-time switching mode that determines the turn-on timings of the switch so as to keep the switch off until a duration of the off-time of the switch reaches the peak off-time value corresponding to the count at which time the switch is turned on; and controlling the switch to be turned on and off based upon the determined turn-on timings and the determined turn-off timings, respectively.