Non contact AC Line and Neutral Detector Circuit Project

Non contact AC Line and Neutral Detector Circuit

In this article, we will learn how to make non contact AC Line and Neutral Detector Circuit.

In the last post, we learned how to make ESP32 interfacing with Stepper motor.

A non-contact AC line and neutral detector circuit helps identify the presence of AC voltage in wires without direct electrical contact. One common and simple way to create such a detector is by using a voltage sensor module like the ZMPT101B along with additional components to indicate the presence of AC voltage.

Components Required:

1. Battery (9v)
2. Switch button
3. LED
4. Resistors (220, 100k, 1m)
5. Transistor (C945)
6. Jumper wires

Circuit connection:

• Connect base pin of Transistor C945 with the prob
• Connect collector pin of Transistor with one side of resistor 1M
• Connect 2^nd side of Resistor 1M with one terminal of Switch through +ve side of LED and one side of 100k resistor
• Connect 2^nd terminal of switch with +ve terminal of battery
• Connect Emmeter pin of first Transistor with the base pin of 2^nd Transistor C945
• Connect collector pin of 2^nd transistor with 2^nd side of 100k resistor
• Connect Emmeter pin of 2^nd transistor with base pin of 3^rd transistor
• Connect collector pin of 3^rd transistor with the one side of 220 Ω resistor
• Connect 2^nd side of 220Ω resistor with –ve side of LED
• Connect Emmeter pin of 3^rd transistor with –ve terminal of Battery
• Dress up the wires clean and tidy

Circuit Diagram:

Working:

When the Probe detects AC voltage, it generates an output signal that activates the LED through the resistor, indicating the presence of voltage.