Circuit diagram for metal detector using Transistor

Rahul's picture

Offline

Joined: Sep 05, 2018

Replies: 0
Circuit diagram for metal detector using Transistor
September 5, 2018 - 7:23pm

Can i get a Circuit diagram of metal detector using transistor

Aswinth Raj's picture

Offline

Joined: Aug 16, 2016

Replies: 778
Metal Detector using 555 Timer
September 6, 2018 - 7:19am

Hi Rahul,

A Metal Detector requires a air cored inductor. The simplest and quickest way to build a metal detector is by using a 555 Timer. You can find the circuit diagram and explanation here

https://circuitdigest.com/electronic-circuits/simple-metal-detector-circuit

Once you understand the circuit you can also use a transistor in place of 555 if you do not need the beeping sound 

Jayant's picture

Offline

Joined: May 19, 2015

Replies: 166
Transistor metal detector circuit
September 6, 2018 - 11:17am

Surprising enough I found many metal detector circuits that work only with a help of a single transistor like the once shown below

MetalDetector-TappedCoil.gif

This circuit uses a single BC547 NPN transistor. The circuit is claimed to be tested, but the difficult part in building this circuit is with winding the tapped coil. If you looking for a simple easy to build circuit you can also try the circuit given by aswinth.

Do note that these circuits are not foolproof, if you serious into building a good metal detector then this below link will be very useful  

http://www.talkingelectronics.com/projects/200TrCcts/MetalDetectors/MetalDetectors-1.html