Non Contact Voltage Checker

Learn how voltage testers detect AC current

Tester Controls

Status

Offline

How it works:NCVTs detect the alternating electrostatic field generated by AC voltage. They do NOT detect DC voltage (like batteries) or AC voltage blocked by grounded metal shielding.

Live AC Wire (120V/240V)

Radiates alternating electrostatic field.

Neutral AC Wire

Completes circuit, usually 0V relative to ground.

12V DC Battery

Steady field, no alternation for induction.

Shielded AC Cable

Metal jacket blocks electric field.

VOLTSAFE Pro

Drag Tip Over Items

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About Non Contact Voltage Checker

Have you ever wondered how those pen-like voltage testers beep when placed near an outlet, without actually touching bare wire? It's called Capacitive Coupling. This interactive simulator lets you play with a virtual NCVT pen, dragging it over live AC wires, neutral wires, and DC batteries to understand exactly what triggers the detection circuit.