Introduction: How to Make a Cheap and Simple Metal Detector

Picture of How to Make a Cheap and Simple Metal Detector

I'm a big fan of pirates. You know how they hunt for treasure. But hunting for treasure isn't always easy. BUT I have a thing that might help you. The SIMPLEST and CHEAPEST metal detector.

Step 1: 555 Ic

Picture of 555 Ic

You should first know a little about the 555 ic. There are totaly 8 pins in it. The pinout is given in this step.

Step 2: Collecting the Things

This metal detector is very simple and is based upon a very famous and easily available ic which is 555 ic. The things that you will need to make this metal detector are

555 ic
47k resistor
2.2 uf capacitor- 2
10 uf capacitor
8 ohm speaker
6 to 12v dc power supply
10 mh (milli henry) inductor/choke

Step 3: Making the Metal Detector

Picture of Making the Metal Detector

Assemble the circuit on a perfboard or pcb except the inductor. Attach two long wires at the place of the inductor. Use a long rod and place the inductor at the end. If you are still confused about the installing of the inductor and the circuit just see the picture. The schematic is given in this step.

Step 4: How It Works?

Picture of How It Works?

If there is any treasure underneath your house or your garden or anywhere, now you can find it.This metal detector can detect metal as well as magnets. When a piece of metal or magnet is brought close to the inductor/choke the output frequency changes and you can hear sound from the speaker. The schematic and info were taken from


medossa (author)2012-10-11

What's the range ? how deeply buried objects can it detect ?

jumper1111 (author)medossa2012-10-11

It depends on the inductor. If you use a 10 mh inductor it will detect upto 1 to 2 metre deep.

AmelM (author)jumper11112014-12-10

can we increase the inductance from 10mH and do we must to change the capacitor ?

what is also the frequency of operation of this circuit

ray.aa7ih (author)AmelM2017-11-03

If all of the components values are nearly accurate, the frequency will be about 93 kHz.

nicholsons1 (author)2017-02-22

what is the range?

9926444303 (author)2016-01-06

why metal detector was contuie buzzing

bajeer zulfiqar (author)2015-12-02

any one have a video of this project lpz mail me at

mati ur rehman (author)2015-11-07

i want to make a metal detector using tda0161, when the detector detects the metal from a specific distance the buzzer sounds but as the metal comes near and near the buzzer sound increases!!

so anyone guide me for this

i m using this with arduino

chandanjyotihazarika (author)2015-07-18

very nice project, I make it

AamirM (author)2015-06-10

JayM14 (author)2015-05-18

arvind.murali.507 (author)2015-02-17

can we use fixed inductor of 10 mh ??? pls reply

I doubt it. I think the point is that the inductance is supposed to change as the coil comes closer to the metal, kind or acting like a ferrite core you might find in a pcb inductor.

MetalDetectingW (author)2014-08-03

skharel (author)2014-06-28

Hello....What is the frequency range for this circuit??? And can you tell me why is the pin number 5 and 7 left as it is???

bdavid2 (author)2013-10-19


vonPongrac (author)2013-09-23

For every one having trouble with building it, I made this metal detector and you can find it here.

mohitey007 (author)2013-08-03

I hav a problem while building it, can anyone tell me where is the pic number 6 and 8 in this circuit diagram of metal detector?? Which is pin 0 in IC 555..?

ghogho (author)2013-07-17

sir., what kind of choke is needed?

jaswanthkalai (author)2013-07-09

can you explain step -3 in detail???

baghdadsig (author)2013-06-28

I am just trying to do somethings. thank you so much.

saniya dutt (author)2013-03-20

does this circuit really work?i don't want to flunk in my college submission...and can u please explain a little more about the working?

Bauwser (author)2013-03-14

to what kind of depth does it go?

faacuunndoo (author)2012-12-30

Did you build it?

rickyd1013 (author)2012-11-02

Over all I like this, I just can really make out step 3 the first photo was a good thing all it needed was a better quality and the second just needed to be explained more. I do thank you for your cheap and easy way to make a metal detector.

randofo (author)2012-10-11

Do you have a picture of the one that you have made?

georion (author)randofo2012-10-22

Yeah, do you have a picture of the ONE you made??
Sure would be NICE to see it . and whats a 10 mh inductor/choke?
and you get 1-2 meters penetration into the earth ?? More details ,PLEASE.

kondzio29 (author)2012-10-12

I'll try and tell you how its working, but im pesimist about it..

rimar2000 (author)2012-10-11

"Cheap and simple" is very tempting. But is it effective?

I ask that because years ago I did another cheap and simple metal detector. When I tested it the first time, I yelled ¬°BINGO! because it detected the proximity of a metallic tool. But soon I realized that it also detected a piece of dirt, masonry, my hand, etc.

jumper1111 (author)rimar20002012-10-11

Don't worry I've tested it myself and it detects only metal and magnets.

rimar2000 (author)jumper11112012-10-12

Thanks jumper1111, I will make one of these when I have a time. I am a compulsive gatherer of "maybe can serve" things.

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