Non-Contact Measurement of Line Voltage

This paper presents a capacitively coupled non-contact voltage sensor, which is specifically optimized for monitoring line voltages ranging from plug level to distribution levels at thousands of volts. The sensor uses a new arrangement of electrostatic pickups to measure the rate of change of an unknown potential, and digitally integrates that the rate of change in order to recover the original signal. This architecture allows for higher sensitivity and more robust disturbance rejection. The cost of the sensor is low because the number of parts is small and the capacitive pickups are integrated into a standard printed circuit board to create a monolithic sensor.