MEAN VALUE RECTIFIER CIRCUIT AND SWITCHING POWER CIRCUIT

摘要

PROBLEM TO BE SOLVED: To reduce a power loss and the size of a mean value rectifier circuit and switching power circuit which mean-value rectifies AC voltage. SOLUTION: A mean value rectifier circuit 1 is provided with a diode D1 for rectifying AC voltage, a capacitor C1 which is charged from the output voltage rectified by the diode D1 through a resistor R1, and a transistor Q1 which turns on and discharges the capacitor C1 through the resistor R1 when backward voltage is applied to the diode D1. The mean value rectifier circuit 1 is connected to a tertiary winding N3 of a transformer T and the mean value rectified output voltage is input to a control circuit 2 to control the on/off of a switching transistor Q. The switching power circuit stabilizes the output DC voltage of a rectifying and smoothing circuit 3 connected to a secondary winding N2 of the transformer T.