Capacitive non-contact voltage sensing method and apparatus

A non-contact electric potential meter system suitable for obtaining a determination of a voltage between a first hot conductor of a first alternating current (AC) electrical circuit and a reference potential, without direct electrical contact to the first hot conductor and without comparison to a second AC voltage signal, the non-contact electric potential meter system comprising:

• a flexible sensing attachment providing a measurement region configured to receive the first hot conductor without interruption of the first hot conductor,
• wherein the flexible sensing attachment in operation is configured to at least partly surround the first hot conductor;
• and
• a capacitive AC voltage sensing mechanism, comprising:
• an electrode situated near the first hot conductor when the measurement region has received the first hot conductor;
• waveform-sensing electronic circuitry configured to obtain an AC voltage waveform induced by capacitive coupling between the first hot conductor and the electrode;
• capacitance-determining electronic circuitry configured to obtain a scaling factor based on a coupling capacitance formed between the first hot conductor and the electrode;
• and
• signal processing electronic circuitry configured to obtain, from the AC voltage waveform obtained by the waveform-sensing electronic circuitry and the coupling capacitance-based scaling factor obtained by the capacitance-determining electronic circuitry, the voltage between the first hot conductor and the reference potential.

A non-contact electric potential meter system suitable for obtaining a determination of a voltage between a first hot conductor of a first alternating current (AC) electrical circuit and a reference potential, without direct electrical contact to the first hot conductor and without comparison to a second AC voltage signal, the non-contact electric potential meter system comprising:

• a measurement region configured to receive the first hot conductor without interruption of the first hot conductor;
• and
• a capacitive AC voltage sensing mechanism, comprising:
• an electrode situated near the first hot conductor when the measurement region has received the first hot conductor;
• waveform-sensing electronic circuitry configured to obtain an AC voltage waveform induced by capacitive coupling between the first hot conductor and the electrode;
• capacitance-determining electronic circuitry configured to obtain a scaling factor based on a coupling capacitance formed between the first hot conductor and the electrode;
• wherein the capacitance-determining electronic circuitry includes a shield driver for driving a shield constructed from high-conductivity material;
• and
• signal processing electronic circuitry configured to obtain, from the AC voltage waveform obtained by the waveform-sensing electronic circuitry and the coupling capacitance-based scaling factor obtained by the capacitance-determining electronic circuitry, the voltage between the first hot conductor and the reference potential.