Isolated Capacitance Line Voltage Sensor

摘要

Isolated capacitance line voltage sensing is provided that avoids metal-to-metal contact for voltage sensing of a power signal present on a power wire. An external conductor is positioned by the power wire, creating a capacitor with the power wire conductor, insulation, and external conductor. The capacitance is used to measure the electric field, indicating a voltage level for the powered wire. The impedance mismatch caused by the capacitance is transformed. The impedance transformation circuit may be integrated with the external conductor, allowing voltage sensing by a voltage meter having a lower input impedance. A manual or automatic calibration circuit may be provided to ensure the measured voltage represents the actual voltage on the power wire.

主权项

1. A method for isolated capacitance line voltage sensing, the method comprising:
placing an added conductor against electrical insulation material of a power wire while power is present on a power conductor of the power wire, the power wire connected with a disconnect panel; and measuring a voltage as a function of a capacitance between the added conductor and the power conductor.