THREE PHASE VOLTAGE SENSING DEVICE FOR WATT-HOUR METER

摘要

The various embodiments of the present invention provide a device and method to detect and measure the line voltage in a three phase energy meter. The device has protective impedance connected to each line source to detect and measure each line voltage. At least two resistances are serially connected to each line source to forma protective impedance network. The measured line voltages are level shifted and conditioned using a voltage level shift circuit and a signal conditioning circuit before being input into an ADC in a microcontroller. The microcontroller processes the input digital signal to estimate the actual line voltage value.