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.
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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 talkingelectronics.com
ChandanZ15 days ago
very nice project, I make it
AamirM1 month ago
JayM142 months ago

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.

medossa2 years ago
What's the range ? how deeply buried objects can it detect ?
jumper1111 (author)  medossa2 years ago
It depends on the inductor. If you use a 10 mh inductor it will detect upto 1 to 2 metre deep.
AmelM jumper11117 months ago

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


skharel1 year ago

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???

bdavid21 year ago
vonPongrac1 year ago
For every one having trouble with building it, I made this metal detector and you can find it here.
mohitey0072 years ago
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..?
ghogho2 years ago
sir., what kind of choke is needed?
can you explain step -3 in detail???
baghdadsig2 years ago
I am just trying to do somethings. thank you so much.
saniya dutt2 years ago
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?
Bauwser2 years ago
to what kind of depth does it go?
faacuunndoo2 years ago
Did you build it?
rickyd10132 years ago
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.
randofo2 years ago
Do you have a picture of the one that you have made?
georion randofo2 years ago
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.
kondzio292 years ago
I'll try and tell you how its working, but im pesimist about it..
rimar20002 years ago
"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)  rimar20002 years ago
Don't worry I've tested it myself and it detects only metal and magnets.
Thanks jumper1111, I will make one of these when I have a time. I am a compulsive gatherer of "maybe can serve" things.