WBK1V1DU01(0-1000V Input AC Voltage Monitoring Using Arduino) uses a special isolation module to monitor the AC voltage in the power grid and circuit in real time. When the AC voltage exceeds the set upper limit value, the output exceeds the limit alarm signal, and the output signal is the relay contact signal. The operating limit value of the AC voltage can be arbitrarily set within the input range. The input and output of the product are completely isolated, with high precision, high isolation and low drift. It can be applied to motor overload monitoring, power loss detection, motion verification, signal isolation conversion and other occasions.