The single phase electric meter uses the eddy current generated by the voltage and current coils on the aluminum disk to interact with the alternating magnetic flux to generate electromagnetic force, which makes the aluminum disk rotate, and at the same time introduces the braking torque, so that the rotation speed of the aluminum disk is proportional to the load power. It is driven by gears, and the number of rotations of the turntable is calculated by the counter to measure the electric energy. Therefore, the main structure of the watt-hour meter is composed of voltage coils, current coils, turntables, rotating shafts, brake magnets, gears, counters, etc.