| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching power supply unit capable of easily evading a latch operation when power supply is reactivated. SOLUTION: The switching power supply unit 10 includes: a capacitor Cin provided between both poles of input lines 12, 13; an IC 14 for switching power supply for controlling the on/off of the switching element Q1; a capacitor C1 for operating the IC 14; auxiliary winding 15 provided in a transformer T, for charging the capacitor C1; an excess current detecting resistor R1 for detecting an excess current flowing through the switching element Q1; output lines 18, 19 connected to the secondary side of the transformer T; a rectifier D2 provided in the output lines 18, 19, for converting an AC outputted from the transformer T to a DC; and a smoothing capacitor C2 provided between both poles of the output lines 18, 19 where the DC flows. A diode D4 is provided, an anode side thereof being connected to the side of the capacitor C1, and a cathode side thereof being connected to the side of Cin. COPYRIGHT: (C)2012,JPO&INPIT |
