prepaid electric meter

there are two basic function modules in the meter separately named the energy metering module and the MPU controller module ,the energy metering module adopts well selected special integrated circuits as will send the pules frequency to the MPU to accumulate the consumption of the electricity the MPU controller module transfers message between the prepaid card and the port of card to realize the prepaid meter function and other function main technical data :1.utmost working voltage :0.8 1.15 of reference voltage normally voltage :0.9 1.1 reference voltage 2.dielectrical voltage :more than 2000vac (50Hz)3.power consumption : less than 2W/10VA4.data protection : data store time after 10 year power off 5.purchase electricity first then use electricity 6.alarm for lack of residual electricity 7.record information of power utilization 8.one card for one user ,anti tamper 9.display residual electricity accumulate and alarm electricity 10 specified working temperature :-10 45 degree 11.utmost working temperature :-25 60 degree 12.relative humidity : less than 85%