220V Cooling Fan overall layout

"220V Cooling Fan" 220V mains voltage through the transformer will become after the AC voltage of 15V, after rectifier circuit into a DC voltage of about plus or minus 15V. -15V Voltage to the buffer amplifier integrated amplifier to provide a negative voltage. "220V Cooling Fan" + 15V DC voltage by five after V into a stable 5V voltage regulator microcontroller and D / A digital-analog converter IC provides operating voltage, when the power is turned on 89C51 is reset voltage reset, the internal start execution of the program, and the corresponding output voltage. "dota2雷竞技下载 " switch button, press a button next machine in standby mode. Power no voltage output, press any key to boot.