Design of Clamp Forward Converter Used in Computing Devices

In this paper, we implement a circuit topology for the gold standard ATX80+.The total output power is 255 watts under full load operation. An active-clamping ZVS forward converter is adopted to provide main power and in secondary side, the BUCK circuit technology is adopted to provide 3 sets power +12V, +5V and +3.3V. To eliminate the current harmonics and to achieve high power factor, an active power factor corrector is added to the implemented power supply. And a two-step follower boost circuit is used to decrease PFCs output voltage which will reduce power losses of the switching loss and conduction loss during loads of light load and typical load. During high load, in active clamp circuit, output diode will be converted into MOSFET, and a current transformer both are used to reduce total power consumption in order to comfort the EPA regulation.