Patent ID: 9166470
Filing Date: 2015-10-20
Classification: H02M,Y02B

Abstract:
1. A method for power factor correction for a voltage converter, wherein a DC voltage or a rectified AC input voltage feeds an inductor, the inductor is repeatedly charged and discharged by a clocked switch by virtue of said switch closing and opening, a discharging current from the inductor is supplied to an output of the converter via a diode, during the discharge phase, a voltage corresponding to a DC output voltage is detected, a temporal range is established at which the discharging current reaches or crosses a zero line at the end of a discharge phase, while evaluating the detected output voltage, and the time when the discharging current reaches or crosses the zero line, switch-on and switch-off signals for clocking the switch are generated, and the switch is switched on again no earlier than after a specific minimum switch-off time of the switch has elapsed and no later than after a specific maximum switch-off time of the switch has elapsed, wherein zero crossing detector signals are detected once the minimum switch-off time has elapsed but before the maximum switch-off time has elapsed and cause the switch to switch on again without a delay.