Ordinary electronic electric energy meter is just a simple measurement tool, it is not controllable and cannot realize other functions that people need, such as intelligent management and monitoring. In order to solve the problem of arrears in electricity bills and realize the function of buying electricity first and then using electricity, prepaid electricity meter came into being.

Compared with ordinary electronic watt-hour meters, prepaid watt-hour meters have added microprocessors, IC card interfaces, and internal tripping circuit breakers. The prepaid electric energy meter consists of three main functions: one is the electric energy measurement part, the second is the microprocessor control part, and the third is the trip device. The energy metering part uses a dedicated metering circuit like ordinary electronic energy meters to generate a pulse sequence indicating how much electricity is used, and send it to the microprocessor for energy metering. The microprocessor transmits the power usage authority through the electrical card interface and the electrical energy card, and trips The device realizes control functions such as on and off.

The core of the electric energy meter is the microcontroller, which completes the functions of measurement, display, information storage, exchange, control, etc. The electric energy meter becomes intelligent because of it, so as to realize the functions that people need to achieve.

For single phase meter IC card meters, the power is directly supplied by AC conversion.