The power supply is a tool to measure the voltage value. From the earliest pointer power supply to the later digital power supply, the power supply has gone through rough to delicate, rough to precise, low resolution to high resolution, small range to large range. After a long time of development and progress, the power supply has made a qualitative leap in the technical level. The basic principle of traditional power supply is the magnetic effect of current. Generally, the power supply normally has three terminals, one negative terminal, two positive terminals, just two ranges. The voltage value of components increases with the increase of current, and the power supply and components are connected in parallelSingle chip microcomputer includes processor, which can read and write ram of random memory device. It can only read ROM of memory device, timing and counting function, input and output pin devices and many other ultra small processors in one device. The birth of microcontroller has influenced the design of the whole electronic industry. This development solution has become very popular, completely replacing the previous development solution. In the past ten years, MCU has been applied in many fields, such as industrial operation, automotive electronics, intelligent industry and operation, intelligent operation, unmanned operation and aerospace office. MCU not only has the advantages of small space, small quality, low energy consumption, low cost, stability and development compatibility, but also has been applied in many fields and used in many daily products.