AC-DC CONVERTER

• Main Author: MIZUTANI YOSHIO
• Format: Patent
• Language: English
• Published: 07.10.1997
• Edition: 6
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

PROBLEM TO BE SOLVED: To realize a stable operation without setting an unnecessarily high output voltage, by a method wherein the rise of the output voltage of a booster converter, which is not controlled by a 1st control circuit because of the response characteristics, is controlled by a 2nd control circuit having a high response speed. SOLUTION: A 1st control circuit 17 which is composed of a current detection circuit 9, a voltage detection circuit 10 and a signal circuit 11 outputting a signal (1) determines an ON-time ratio when an output voltage E0 is lower than the output voltage value of a converter and controls ON/OFF of a switching means 5 so as to limit the peak value of an input current in order to improve the power factor and stabilize the output voltage of the converter. A 2nd control circuit has the frequency characteristics higher than the frequency of an input AC power supply 1, detects the voltage E0 of a filter capacitor 7, compares the voltage E0 with a reference voltage, and outputs a signal (2) which controls ON/OFF of the switching means 5 so as to have the ON-time ratio reduced according to the voltage rise. A driving circuit 12 turns on and off the switching means 5 with a driving pulse in accordance with OR of the signal (1) and signal (2).