PURPOSE: To improve the power factor on power source side in a capacitor input type rectifying circuit.
CONSTITUTION: An AC switch such as a TRIAC 2 or the like and a reactor 3 are connected in series between a capacitor input type rectifying circuit comprising diodes 5-8 and a capacitor 9 and an AC power source. A capacitor 4 is connected in parallel to the input part of the capacity input type rectifying circuit. The TRIAC 2 is turned on, being delayed by a certain time from the zero cross point of AC power voltage, or turned on with the timing being decided based on the output voltage of the capacitor input type rectifying circuit or the comparison between this output voltage and the AC power source voltage. Or, the TRIAC 2 is turned on in every half cycle of the power source voltage by connecting the capacitor 4 to the junction between the reactor 4 and the diodes 5 and 7.
FUJITA KOETSU
TORIYAMA FUMIO
HIEDA MASAAKI
OKUBO ATSUSHI
