说明：  89C51 AD采集交流电的程序50HZ的交流电经过精密整流以后每个周期单通道采集800个点分两个通道采集电压和电流并计算S，P，Q，相位角g
(89C51 AD acquisition procedures AC 50HZ precision rectifier of alternating current through each cycle after the 800 points collected single-channel two-channel voltage and current acquisition and calculate the S, P, Q, phase angle g)