Patent ID: 6737846
Filing Date: 2004-05-18
Classification: G05F

Abstract:
An Active Power Factor Correction (APFC) apparatus having improved output voltage regulation, for switching a 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 controllable power switch connected in tandem with said array and said input inductor, comprising:a) sampling circuitry, for sampling the instantaneous value of the output voltage; b) control circuitry, for controlling the switching time of said controllable switch in response to an error signal, and, thereby, causing said instantaneous value to be essentially similar to a predetermined nominal value; c) amplifier circuitry, for generating said error signal, said amplifier circuitry having at least a reference input connected to a reference signal, being determined according to said nominal value and sampling circuitry, and an input, to which an input signal is provided, said error signal represents the deviation of said input signal from said reference signal, said input signal being associated with the sampled instantaneous value; and d) circuitry for providing a low-pass filtered first indication signal to said input, whenever the deviation, of the output signal, of said sampling circuitry, from said reference signal, does not exceed a predetermined value, or otherwise, for providing a second indication signal to said amplifier circuitry whenever said deviation exceeds said predetermined value, said second indication signal being related to higher deviation values.