Contrary to what one might think, metal detection is not reserved for certain settings such as airports or places of large gatherings. It is possible to make it a fun activity or even a lucrative one. Indeed, you have the possibility of using detection to recover metallic objects found in nature. You will then be able to sell these items and thus earn additional income. During your search, you may find valuable items.
You do not have to buy a metal detector to start this activity. You can make your own if you are handy. This allows you to save money, learn and have an object built according to your needs. Below, we give you tips for building a metal detector.
Gather the components needed to make the metal detector
As with any crafting, the first step in building a metal detector is to research the materials you will need. You should know that such a device is made up of several pieces of equipment. Since we are in the DIY field, you will be able to use everyday items to make the metal detector.
The detection coil
A metal detector, whether basic or not, must have a coil. You can make this coil yourself using copper wire. This wire can be recovered from old electric motors, relay coils or transformers. You also have the option of recovering copper wire from electrical appliance chargers and electric fans.
You will need to place the coil on a support so that it holds. A wooden or plastic object can be used as a support for the spool. Objects such as a piece of PVC, a curtain ring or the lid of a small box can do the trick.
The oscillator and the amplifier
An oscillator will be needed in your metal detector. The role of this device is to produce an electrical signal which will travel through the coil. This oscillating current will be the basis of an electromagnetic field which is sensitive to metallic objects.
To make an oscillator, you can use various everyday objects. You will need to make a combination between transistors, capacitors and resistors. You can salvage these devices from old radios, computer motherboards or televisions.
The amplifier, as its name suggests, makes the signal stronger and increases the sensitivity of the metal detector. When you put an amplifier in your metal detector, you will be able to find small metal objects or those located at a great depth. If you are using a metal detector to search for treasure, for example, an amplifier will be necessary.
Amplifiers consist of an integrated amplifier circuit and additional capacitors. Just like with the oscillator, you can turn to old devices to find these items.
The electronic circuit
The electronic circuit is composed of the demodulation circuit, the output circuit and the power Source.
The demodulation circuit is present in the detector to process the signal which is produced by the oscillator. This signal is then converted into a form that can be understood by the user. The demodulation circuit is made up of diodes and capacitors. Diodes can be found in old devices like phone chargers and computer power supplies.
The output circuit is the element through which you have the signal notifying you of the presence of metals. This may be a visual signal or an audible indicator. You can use headphones or a speaker salvaged from an electronic toy, an old radio, or damaged headphones. If you prefer a visual signal, you can opt for LEDs available on remote controls or toys.
The power Source provides power to the entire device. You just need a sufficiently powerful battery. You can opt for a 9 V battery to recover from a smoke detector for example.
The box
The case is used to protect all of your electronic components. It also makes handling the equipment easier. To make it, you can use a plastic box generally used in the kitchen. You also need a support rod which can be made from PVC pipe, a broom handle or a telescopic antenna.
Build the metal detector
Now that you have gathered all the necessary items, you can move on to building your metal detector. Note that, in addition to the different equipment, you will need a certain number of tools:
- Cutting pliers;
- A screwdriver ;
- A stripping pliers;
- A soldering iron;
- A screwdriver ;
- Insulating tape.
It is important to wear protective glasses when disassembling various electronic devices. When it comes to handling sharp tools, take all precautions. You can follow the following steps to make the metal detector.
Step 1: Preparing the coil and building the oscillator circuit
Preparing the pickup coil involves wrapping the copper wire around the holder. You can do about 50 turns. It is important that the turns are done well and are regular. You must also leave free wire at the ends for connections.
To build the oscillator circuit, connect the different components such as capacitors, transistors and resistors. Use the soldering iron to solder these components together.
Step 2: Connecting the Coil to the Oscillator
This step simply involves connecting the wires together. You will connect the ends of the coil with the points of the oscillator. The wires to be used must be connection wires in order to have good conductivity.
Step 3: Setting up the amplifier and connecting the output circuit
You can now connect the amplifier. The more transistors there are, the more the signal will be amplified. Don’t forget to solder the different components together. The output circuit (speaker or LED) will be connected to the end of the demodulation circuit. Connections must be secure and well insulated.
Step 4: assembling the case
The last step is assembling the case. This involves putting the different components in the box that you have previously chosen. Then you can fix them using adhesive tape and zip ties. The coil must also be attached to the sensing rod. If you have planned a switch, make holes in the box to pass the wires through and connect them to the circuit.
Test and use the metal detector
At the end of manufacturing your metal detector, you will move on to testing. You must first ensure that all connections are in place, insulated and soldered. You can put the battery in making sure the switch is OFF.
You can now turn on the device by pressing ON. You will hear a background noise which shows you that your device is turned on. Please slowly approach a metal object towards the detection coil. You will notice a change in the tone of your detector or a change in the LED light. You can also check the range of the device by gradually moving the object further away. By doing this, you will be able to note the maximum distance your device is sensitive to.
The metal detector can be used in various fields. You can use it to carry out a treasure hunt in parks and beaches. You can find coins, electronic gadgets, jewelry, etc. there. This device can also be used for school projects and for collecting and recycling metals.
Making a metal detector allows you to use your electrical and DIY skills. It’s a great activity to spend some time. With your loved ones, you can make your own metal detector and go treasure hunting.
