Universal power converter with single, shared power transformation circuit

摘要

A power conversion method and apparatus convert an AC input voltage signal or a DC input voltage signal to a DC output voltage signal suitable for driving a DC load. The power converter includes a first voltage stage coupled to a first pair of input terminals to receive a rectified AC input voltage signal. A second voltage stage is coupled to a second pair of input terminals to receive a DC input voltage signal from a battery source. A transistor drive circuit is connected between the input terminals and the first and second voltage stages. The drive circuit causes energy to be stored in either the first or second voltage stage depending upon whether an AC or a DC voltage signal is applied to the input terminals. The stored energy is released to a third voltage stage to produce a DC output voltage at output terminals coupled to a power supply of a portable device, such as a personal computer.