7279和TLC549数字电压表，由51单片机控制的，通过模数TL549采样制作的电压表，同时由7279控制的数码管显示-7279, and TLC549 digital voltage meter, controlled by the microcontroller 51 through the production of modulus TL549 sampling voltmeter, accompanied by a 7279-controlled LED display

AD1674与AT89C51进行数模转换，实现数字电压表功能-AD1674 and AT89C51 digital to analog conversion, digital voltmeter function