This simple circuit can indicate the condition of Phase, Neutral and Earth wiring in the domestic power supply. If Phase, Neutral and Earth lines are intact, Red, Yellow and Green LEDs glow. If Earth line is brocken, Green LED remains off. If either Phase or Neutral line is brocken, all LEDs remains off. The circuit can be enclosed in a Three pin plug. Just plug it in the socket and check the conditions of home wiring.


Components required
1. 100 K ½ watt resistors – 3 Nos
2. 1N 4007 Diodes – 3 Nos
3. Red LED – 1
4. Green LED – 1
5. Yellow LED – 1
6. Three pin plug – 1

Circuit Diagram

Connect the components as shown in the circuit diagram. Enclose the circuit in the plug as shown in the image. Give adequate spacing and sleeving to avoid short circuit.




Line Tester with Volt Meter

Testing



Caution – This circuit is directly connected to 220 volt AC and can give fatal shock if handled carelessly. Do not touch or troubleshoot, if the circuit is connected to AC.