Non Contact AC Tester. Home Utility Circuit 7

IMAGEThis circuit is highly useful to detect the presence of AC in mains wiring without making contact with AC line. The circuit can be used as a Non Contact AC tester to test the live and broken wire. It is highly useful to check breaks in the concealed wiring. The Flashing of LED indicates the presence of AC. The circuit can detect 50 Hz Ac hum from a distance of I foot.
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AC Scanner. Simple Design 11

With a single IC you can make a simple Non Contact AC tester. Just move in front of an AC wire, switch board etc that carrying AC, the LEDs in the circuit runs indicating the presence of AC in the wire.
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Earth Fault Indicator. Design Note 17


This is my circuit published in Electronics For You Magazine. I have designed this circuit for checking the Earth connection in the power sockets ,whether it is intact or not. Earth connection is a must in power sockets especially if the gadget connecting has a metal body. If there is any leakage from live wire, the earth connection will bleed the current to earth and protect us from shock. So this circuit can be used to check the power sockets before using gadgets like Heater, Electric Iron etc. It also indicates whether there is power in the socket and the polarity of Phase and Neutral is correct.
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Mains Tester. How Stuff Works

The common AC tester is the simplest form of tool to test the presence of AC in the mains wiring. The Screwdriver type AC tester has a Neon lamp inside which glows when the current passes from the mains wiring to the ground through the user’s body. It uses the stray capacitance of the body to complete the circuit.
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Live Wire Scanner. Design Trick 11

Try this single IC circuit for Non contact detection of current in live wires. It can detect the presence of AC from a distance of 30cm or more without touching the bare points of live wire. It is ideal to detect cable break, switch board faults, earth leakage etc. The circuit detects the e.m.f (called AC hum) present around the live wire when the electricity passes. Only a single IC CD4033 can do the trick.
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