Patent ID: 6654259
Filing Date: 2003-11-25
Classification: H02M,Y02B

Abstract:
A resonance type switching power supply unit having a switching circuit for carrying out a switching operation on an inputted direct current, a converter transformer supplied with a switched output from the switching circuit, a resonator including a coil of said converter transformer as a resonator element, a rectifier for rectifying an output of said converter transformer and supplying a rectified output to a load connected to said resonance type switching power supply unit, and a switching controller for controlling a switching frequency of said switching circuit depending on the rectified output deriving from said rectifier, said converter transformer being arranged as one capable of varying a leakage inductance thereof, and said resonance type switching power supply unit comprising:a detector for detecting an input voltage applied to said switching circuit and an output current supplied from said rectifier to the load; and a leakage inductance controller for variably controlling the leakage inductance of said converter transformer.