Ordinary electronic energy meters are just a simple measurement tool. It is not controllable and cannot achieve other functions (such as intelligent management, monitoring, etc.) that people need. In order to solve the problem of arrears of electricity bills and realize the function of buying electricity first and then using electricity, pre-paid energy meters came into being. Compared with ordinary electronic watt-hour meters, pre-paid watt-hour meters have added microprocessors, IC card interfaces, and internal tripping electrical appliances. The prepaid energy meter consists of three main functions: one is the energy measurement part, the other is the microprocessor control part (including the IC card), 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 sends it to the microprocessor for energy metering. The microprocessor transmits the electricity to the energy card (IC card) through the card interface Authority, realize on / off control functions through trip device
The core of the energy meter is a microcontroller (CPU), which completes the functions of metering, display, information storage, exchange, and control. The energy meter becomes intelligent because of it, so as to achieve the functions that people need to achieve.
1. Electromechanical: Sampling from the meter disc of the mechanical instrument to convert the rotation of the meter disc into an electrical pulse signal.
2. Electronic type: The data collection, measurement and conversion into electrical pulse signals are performed directly by the electronic integrated circuit.
3. LED / LCD display module: used to display the measurement data and working status of the IC card meter.
4, real-time clock: used to record the clock and calendar, to assist the microcontroller to complete the measurement of various rates and data statistics by day, week and month.
5. IC card interface: used for IC card meter and IC card for data exchange and authentication.
6. ESAM module / E2PROM: It is used to store the metering and status data in the IC card table or to perform system key authentication with the IC card.
7. Load control switch: A switch used to control the user's electricity. The IC card meter can output a control signal to close or open it.
8, power module: used to provide power supply to the IC card meter. For single-phase IC card meters, AC power is supplied directly.