Patent ID: 6882551
Filing Date: 2005-04-19
Classification: H02M,Y02B

Abstract:
1. A switching power supply device for converting an alternating voltage into a DC voltage with a higher amplitude than that of the alternating voltage so as to output high DC voltage, the device having a switching element for controlling a full-wave rectified alternating voltage into an on/off state, the switching power supply device comprising: a controller having an error voltage generator for generating an error voltage according to a difference between the output voltage and a first reference voltage and a computing unit for computing a current target value by relating the full-wave rectified alternating voltage with the error voltage, the controller controlling the switching element into a nonconductive state when an electric current flowing in the switching element reaches the current target value; a comparator for comparing the error voltage with a second reference voltage and outputting a switching signal when the error voltage is higher than the second reference voltage; and a reference voltage generator for generating the first reference voltage and setting the first reference voltage lower according to the switching signal.