How to Make a Metal Detector Out of Household Items

How to Make a Metal Detector

Metal detectors can be really expensive. Did you know that you can make a metal detector by using simple household items? You can’t make the complex metal detectors but you can create the simple versions of it. The making process can be a bit critical so make sure to do a proper research online before getting started.

Creating a Metal Detector

If you are trying to make a metal detector from the items that don’t have a magnetic field, you should know how to connect electrical circuits. It can be dangerous for you as there is a risk of spark if wired wrongly. If you want to play with the circuits, make sure you have done a proper research online. You can also take help from someone who is master of this electrical field.

One simple way of making a metal detector is by using items that have a magnetic field on it. Calculator and radio are the best examples of household items that can be used to make a metal detector.

Basic Functioning of Metal Detector

A metal detector uses the principle of electromagnetic induction. The current flows in a particular direction in the search coil when the metal detector is turned on. This current produces a magnetic field around the coil. When the search comes near to any metal, magnetic field induces eddy current in the metal.

The eddy current then generates its own magnetic field. Due to this magnetic field, search coil receives an opposite current. This is how the presence of a metal is detected by the metal detector. The user comes to know about the metal by hearing an audio signal of a particular tone in the headphones.

Make a Metal Detector Using Calculator and Radio

When you are making a metal detector at home firstly you need a calculator, AM radio and some tape. Start by turning the AM radio on. Tune in to its highest bandwidth but make sure not to turn on any broadcast station. The broadcast station can lead to interference. Turn on the volume to its maximum level and make sure that you are only hearing the static.

Now, turn on both the calculator and the radio. Set the position of calculator close to the radio till you hear the loud tone. Once you get the right position, stick them together by using a tape while maintaining the placement. Just make sure that they don’t slip apart.

Homemade Metal Detectors

Check the devices to see whether they are emitting a constant tone. That constant tone should be loud enough to hear properly. Once the calculator and radio are adjusted to produce the right volume of sound, they can be taped together onto a rod.

Then, attach the devices to the board. You can use a broomstick, pole, ruler or anything that would hold all of these together against the ground. If you don’t have a tape you can use a glue to attach it to a shaft.

The metal detector is now ready for the testing process. Before taking it to the real world, you can just test it on to the household items first. This can help you determine whether your device is working correctly or not. Test it on the items like jewelry, silver, aluminum foil, coins etc. The faster your metal detector detects the metals and generates the audio signals, the better it’s going to work outside.

Make a Metal Detector Using a Smartphone

If you didn’t like the above DIY process and you want to save your time, the smartphone is an alternative for that. It’s a really simple process. You just have to download the metal detecting application from the app store. After downloading, your phone can be programmed to detect the metals.

After programming your phone, test it on different metals and see if the app is working or not. Go through all the instructions of the applications before using it. You need to invest your time in reading the instructions if you want the expected results. If the app is not working correctly, switch on to other applications from the app store. You have to use the hit and trial in this case.

The application works by detecting changes in the magnetic fields. You can see the magnetic field varying on your screen when you pass over a metal.


You need to consider the fact that the homemade metal detectors can’t be as good as the ones available in the market. Homemade metal detectors give you an approximate result, not an exact location. The metal may or may not be present at the particular location. They can’t face the harsh challenges of nature like dirt, water etc. Don’t expect to find the metals that are buried deep down.

If you have misplaced your jewelry or any accessory made of metal at home, then homemade metal detector can come at the rescue. So, homemade metal detectors have their own pros and cons. It’s just that you should know the right place to use them.


If you are a DIYer and you relish learning something new then making a metal detector can be a pleasant activity for you. On the other hand, you can save your money by making it at home. They are not as reliable as the readymade ones. You need to do time to time readjustment to make sure everything is working flawlessly.

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