Household meter of system components

Common household meter consists of two systems: measurement system and chip processing systems.
Measuring system: a single-phase electronic energy meter. Working principle is: the completion of the voltage divider sampling completed by the sampling resistor current sampling, after electri cenergy meterthe voltage and current signals from the multiplier is converted to power signal, the V / T transformation, promoting the work of degrees, and the pulse signal Enter the SCM system.
Users need to purchase payment in the electricity sector, the purchase of electricity in the sale of electric motors to be written into the user card, the card is passed to the electric meter, electric card after repeated encryption to ensure that users can reliably use. When the purchase power is exhausted, the table will automatically cut off the power supply circuit relay. Of course, electronic watch

Power relative to the machine table should be large, because the drive digital tube or LCD with backlight  Voltage stabilizer more current, general digital tube (equivalent to eight LED lights side by side, but in different positions, according to the light off to display different numbers) lit that takes about 20mA of current, displayed more self-

Greater consumption, but now most mechanical meters do very sensitive, self-consumption is about January 1 degree table Loss (Power Supply Bureau in household electricity bills will be more kilowatt loss), and the mechanical meter is without electricity not consumed, but there will be electronic form without losses, generally with three

Segment LED + microcontroller needs about 2-3W's own consumption, more power will be wasted