| 摘要 |
PURPOSE: A high efficiency power supply is provided to achieve improved power efficiency by minimizing the dropout voltage generated from a linear regulator regardless of fluctuation of AC input power or load current fluctuation of output terminal. CONSTITUTION: A high efficiency power supply comprises a transformer(210), a rectifier(220), a switching unit(230), a linear regulator(240), and a post regulator(250). The transformer applies input AC power to a primary coil, and performs a transform operation to the voltage applied to a secondary coil in accordance with the winding ratio of the primary coil and the secondary coil. The rectifier is arranged to rectify AC voltage output from the secondary coil of the transformer. The switching unit outputs or cuts off the signal output from the rectifier in accordance with a switching control signal. The linear regulator converts the signal output from the switching unit into a predetermined DC voltage. The post regulator generates a switching control signal having a length of a switching on/off section varying in accordance with the size of the difference signal between the input terminal voltage and output terminal voltage of the linear regulator. |
