COMPENSATING METHOD FOR LEAKAGE INDUCTANCE OF TRANSFORMER OF SWITCHING POWER SOURCE AND POWER CIRCUIT THUS COMPENSATED

摘要

PROBLEM TO BE SOLVED: To eliminate the secondary-side output voltage variation in a primary winding voltage control system by selecting a rectifier diode, having a junction capacity value which generates a resonance component with the leakage inductance of the transformer of a switching power source, as a rectifier diode to be connected to the primary-side output voltage detecting winding. ;SOLUTION: In a switching power circuit of a primary winding voltage control system, the output of a primary-side output voltage detecting winding L3 is rectified by a diode D1 and smoothed by a capacitor C1, and control is performed so as to make the voltage of the thin capacitor C1 constant. In this case, the value of the leakage inductance Lo of the winding L3 changes in a constant range by a transformer T in use, by the variation of coupling with the primary winding L1 of the transformer T. Here, a resonance component is generated in accordance with the value of the leakage inductance Lo, by suitably selecting the value of the junction capacity of the diode D1, and the voltage value of the capacitor C1 is changed, and the variation of a secondary winding L2 side output voltage is compensated.;COPYRIGHT: (C)1999,JPO