| 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 (102). An external conductor (108) is positioned by the power wire (102), creating a capacitor with the power wire conductor (104), insulation, and external conductor (108). The capacitance is used to measure the electric field, indicating a voltage level for the powered wire (104). The impedance mismatch caused by the capacitance is transformed. The impedance transformation circuit (110) may be integrated with the external conductor (108), allowing voltage sensing by a voltage meter (112) 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 (102). |
