Build a metal detector with your own hands: varieties, detailed instructions, principle of operation and scheme

Nowadays, many people try not to buy metal detectors, and collect them with your own hands. Usually, is considered, what a thing, made with their own hands much worse, than branded copies. Practice has shown, that a quality product can compete with metal detectors, made in production.

Of course, what is this device, may be, will look a little worse in its aesthetic performance, but in terms of technical data, it will be competitive.

General information on the metal detector

Before you start assembling your own metal detector, you need to know the principles of its operation and what types of such equipment can be divided.

Construction

There are basically five types of metal detectors. They differ in search depth and type of metal. They have various functions, which simplify the work, but still, even with such differences, some similarities can be identified.

1. The magnetized coil is one of the main parts, which is located at the bottom of the metal detector. Usually, she is responsible for finding metal products. It depends on the power and size of the coil, at what depth you can find metal objects. in addition, the quality and potential of the magnetized coil is influenced by the operating scheme.
2. The control unit is mainly responsible for controlling the main functions of the metal detector. This part consists of a small processor, speakers, and battery. Other auxiliary functions can be added in modern versions of the metal detector.
3. The holder with an armrest performs the simplest function. This is an element, which connects the control unit and the coil into a single unit. There are many varieties of such owners, which have a constant or variable size. Basically it's done for that, to make a person feel as comfortable as possible when searching for metal objects, rather than leaning constantly.
4. The coil cable is responsible for the interaction between the control unit and the magnetized coil.

The principle of operation

The structure of the metal detector system may seem complicated at first glance. Actually, the whole process is just the attraction of metal products with a magnetized coil. While the coil begins to attract metal parts, magnetic waves pass through it, and after that the signal is heard.

It is worth noting, that the coils operate at low or high frequencies. If the equipment operates at low frequencies, then metal products will mostly be found only at a depth of four meters. in addition, metal detector, which operates at low frequencies, can detect only large samples, while small metal details on the surface will go unnoticed. Metal detector, which responds to high frequencies, vice versa, finds only small details on the surface, at the same time can work at a depth of more than two meters and look for large objects.

Typical varieties

Metal detectors can be divided into 5 types, given the device, which is responsible for transmitting and receiving the signal.

1. The first type of metal detector is made on the type of "reception-transmission". The structure of the device has two inductors, which are responsible for transmitting and receiving the signal, that is, each fulfills its specific purpose. The device works like this, so that the signal at rest of the metal detector does not fall on the receiving coil, and when searching for metal objects, vice versa, there was an amplification of the signal, which then falls into the control unit.
2. The induction type completely repeats the first version of the metal detector, since the system also has two coils, aimed at transmission and reception, but they work as one. When self-assembled, this can cause problems in detecting the reflected signal.
3. Metal detectors, which are made using LC generators, is very popular. Often this type of equipment is made with their own hands. The equipment works only at low frequency, but this, in turn, compensated by ease of use and ease of assembly. The principle of operation is frequency, which changes as you approach a metal object.
4. The quality meter is another option for a metal detector, which also works with an LC generator. The closer the metal is, the lower the quality factor. This metal detector is very easy to assemble with your own hands, but there is one downside, unstable operation at low temperatures.
5. Pulse type metal detectors work by transmitting eddy current, which begins to react to metal objects. At this time, a pulse signal is transmitted to the control unit, which increases or decreases depending on the distance to the metal part.

How to make a metal detector with your own hands?

Making your own homemade metal detector is not too difficult, even if there are no certain skills in electricity and in the system itself. To date, there are quite a number of metal detectors, which can be collected at home. They differ in schemes, which have to be used to create a control unit, materials and complexity of assembly.

Usually, the most complex metal detector is assembled according to the scheme, where it is necessary to install two generators in the system structure at once. This is quite difficult for a beginner. There is also a simpler type of metal detector, which can be safely done at home, use only improvised materials.

Frame

Assembling a homemade metal detector should begin with the development of the case. It should be a simple barbell, which can be welded or connected with fasteners. In fact, there is no specific framework for the case. Here everyone can make a barbell for themselves, but there are some factors to keep in mind.

In the first place, material, which is selected for the manufacture of the body must be strong enough, to withstand the weight of an adult for a long time. in addition, we must not forget about the size of such a bar, after all, if you choose the wrong length for your height, you will have to stand in a bent position for a few minutes each time you search for metal objects.

Many people simplify the task of creating a body using a simple crutch, which also has an armrest at once. The crutch can be easily selected for your height, and is not very expensive.

Search coil

Making a homemade coil to search for is quite difficult, but it is possible. First of all, you need to start creating a device for winding the coil. To begin, take a simple board the size of 18 on 18, nails and cambric.

After that on a board it is necessary to draw an equal circle and to kill for its diameter not less 16 nails, so that they protrude slightly on 2 cm After that, the nails are installed cambrics, which are tightly wrapped with copper wire. At the end of the work, the entire copper circle is firmly fixed with threads, which need to be wound around the entire diameter and treated with epoxy resin.

It is necessary to leave length 4 see conclusion, tighten the coil with insulating tape and shield with foil. Copper wire should be serviced in length 1,25 cm and then rewind it on the spool. Then the action is repeated, a, more precisely, the coil is wrapped with insulating tape. To the conclusion of the coil you need to solder the contact pad.

Control unit

To create a control unit is required:

• rechargeable battery capacity 9 volt;
• schemes;
• speaker on 8 Ohm;
• amplifier transistor.

All the necessary parts can be found in the old transistor type receiver. To assemble the control unit will need to find a suitable housing and mount all the parts.

The circuit and the coil are connected together by a shielded wire. The cable shield is soldered to the coil terminal, insulation is installed, and the cable is fixed to the housing with insulating tape.

Conclusion

To make an entry-level metal detector is quite simple at home with the help of improvised means. Everything you need to do, it is to follow the instructions and assembly diagrams of the equipment. The result is a model, which can be used to search for small metal objects at depths up to 1 m.