| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a switching power unit which restricts an automatic reset only by revising the external circuit of the switching power unit, using a power control IC having a built-in automatic reset function in excessive load. Ž<P>SOLUTION: The switching power unit converts the AC input voltage from an AC power supply AC, rectified through a diode bridge D1, into a desired DC voltage with a switching element Q1 and outputs it. The switching power unit is controlled with the power control IC 100 having the built-in automatic reset function in excessive load. In the power control IC 100, a resistor R0 connects between a power terminal VCC and a smoothing capacitor C1 of a primary circuit, allowing current to flow from the smoothing capacitor C1 side to the power terminal VCC even when power is not supplied from an auxiliary winding Lb in excessive load. Then, the power control IC 100 maintains the voltage of the power terminal VCC at a prescribed level, preventing the automatic reset operation in excessive load to hold a switching suspension state. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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