AC signal acquisition circuit

The invention provides an AC signal acquisition circuit comprising AC signal acquisition modules and an AC signal detection module. Each AC signal acquisition module is used for acquiring AC signals and comprises an AC signal conversion unit, a waveform shift-up unit and a sampling load unit. The AC signal conversion unit comprises an AC transformer which is connected with a live wire and a zero wire. The waveform shift-up unit is used for shifting up the overall waveform setting value of AC signals. The sampling load unit is used for adjusting the sampling values of the AC signals outputted by AC signal acquisition branches. The input end of the sampling load unit is connected with the first end of the AC transformer, and the sampling values of the AC signals are adjusted by adjusting the resistance value of sampling resistance. The AC signal detection module is used for outputting a comparison result to be used as reference for adjusting the resistance value of the sampling resistance of the sampling load u