Abstract
The design of the main power switch on the course of development, future development trends, and the advantages and disadvantages of switching power supply and anti-jamming measures. The design of a typical half-bridge switching power supply design of the structure to control TL494 as the core device and auxiliary power supply by way of its electricity, although the design is complex, but is conducive to increasing the output power of the main power. FET used as a switching device, and its on-deadline fast, conduction losses small, which is the high efficiency switching power supply to provide protection. At the same time, supplemented by over-voltage circuit overcurrent protection circuits, for the security system to provide protection, the introduction of passive PFC ircuit,reducing the electromagnetic crosstalk, to achieve the purpose of environmental protection. Output voltage adjustable so that it could be applied to different occasions. Key words: Pulse Wide Moduation; Half-bridge transformation; TL494
