Nowadays, many people try not to buy metal detectors, but to assemble them with their own hands. As a rule, it is considered that a hand-made thing is much worse than branded copies. Practice has shown that a quality product can compete with metal detectors made in production.
It goes without saying that such a device might look a little worse in terms of aesthetics, but with regard to technical data, it will be competitive.
1 General information on metal detectors
- 1.1 Design
- 1.2 Principle of operation
- 1.3 Typical species
2 How to make a metal detector with your own hands?
- 2.1 Housing
- 2.2 Search coil
- 2.3 Control block
- 3 Conclusion
General information on metal detectors
Before you start assemble your own metal detector, you need to learn the principles of its work and what types can be divided into such a technique.
Most metal detectors are divided into five types. They differ in depth of search and type of metal. They have various functions that simplify the work, but still, even with such differences, some similar features can be identified.
- Magnetized coil - one of the most basic parts, which is located on the bottom of the metal detector. As a rule, it is responsible for the search for metal products. From the power and size of the coil depends on how deep it will be possible to detect metal objects. In addition, the quality and potential of the magnetized coil is affected by the working circuit.
- The control unit responds mainly for managing the main functions of the metal detector. This part consists of a small processor, speakers, and battery. In modern versions of the metal detector, other auxiliary functions may be added.
- Holder with armrest performs the simplest function. This is the element that connects the control unit and the coil into a single unit. There are many varieties of such holders that have one constant or varying size. Basically, this is done so that the person feels as comfortable as possible when searching for metal objects, and does not constantly lean.
- Cable coil is in charge for the interaction between the control unit and the magnetized coil.
Principle of operation
The structure of the metal detector system only at first glance may seem complicated. In fact, the whole process is simply the attraction of metal products using a magnetized coil. While the coil begins to attract metal parts, magnetic waves pass through it, and after that a signal is heard.
It is worth noting that the coils operate at low or high frequencies. If the equipment operates at low frequencies, metal products will mainly found only at a depth of four meters. In addition, a metal detector that operates at low frequencies can detect only large samples, while small metal parts on the surface will remain unnoticed. A metal detector that reacts at high frequencies, on the contrary, finds only small details on surface, while it can not work at a depth of more than two meters and look for large items.
Metal detectors can be divided into 5 types, given the device that is responsible for transmitting and receiving a signal.
- The first type of metal detector is made by type "reception-transmission". The structure of the device has two inductive coils, which are responsible for transmitting and receiving a signal, that is, each performs its specific purpose. The device works so that the signal in a quiet state of the metal detector does not fall on the receiving coil, and when metal objects are searched, on the contrary, the signal was amplified, which then gets into the block management.
- Induction type repeats the first version of the metal detector., since the system also has two coils in place, which are aimed at transmitting and receiving, but they work as one unit. When self-assembly, this can cause problems when detecting the reflected signal.
- Metal detectors that are made with the use of LC - generators, is very popular. Often it is this kind of equipment and make their own hands. The equipment works only at a low frequency, but this, in turn, is compensated by ease of use and ease of assembly. The principle of operation is the frequency, which changes as it approaches the metal object.
- Q-meter - this is another version of the metal detectorWhich also works with an LC generator. The closer the metal is, the lower the quality becomes. It is very easy to assemble such a metal detector with your own hands, but there is one drawback, unstable operation at low temperatures.
- Pulse type of metal detectors works by transmitting eddy current, which begins to react to metal objects. At this time, a pulse signal is transmitted to the control unit, which amplifies or becomes weaker depending on the distance to the metal part.
How to make a metal detector with your own hands?
Make your own homemade metal detector is not too difficult, even if there are no specific skills in the electrics and in the system itself. Today, there is a fairly large number of metal detectors that can be assembled at home. They differ in the schemes that have to be used to create the control unit, materials and assembly complexity.
As a rule, the most sophisticated metal detector is assembled according to a scheme where it is necessary to install two generators in the system structure at once. It is quite difficult for a beginner. There is a simpler type of metal detector, which can be safely made at home, while using only scrap materials.
Assembling a homemade metal detector must begin with the development of the body. It should be a simple bar which can be welded or connected with fasteners. In fact, there is no defined framework of the case. Here, each person can make a barbell for themselves, but it is important to remember some factors.
First of all, the material that 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 can not forget about the size of such a rod, because if you choose the wrong length for your height, each time you search for metal objects you have to stand in a bent for several minutes condition.
Many people simplify the task of creating a case using a simple crutch, which also has an armrest. The crutch can be easily picked up to fit your height, and it is not too expensive.
To make a homemade coil to search is quite difficult, but possible. The first thing you need to start creating a device for winding the coil. First you need to take a simple board of 18 to 18, nails and cambric.
After that you need to draw a smooth circle on the board and hammer in at least 16 nails in diameterso that they protrude a little about 2 cm. After that, the cams are installed on the nails, which are firmly wrapped with copper wire. At the end of the work, the entire copper circle is fastened firmly with threads that need to be wound over the entire diameter and treated with epoxy resin.
It is necessary to leave a length of 4 cm output, tighten the coil with tape and shielded with foil. The copper wire must be trimmed with a length of 1.25 cm and then re-wound it on the coil. Then the action is repeated, and, more precisely, the coil is wrapped with tape. To the conclusion of the coil still need to solder the pad.
To create a control unit you will need:
- 9 volt rechargeable battery;
- 8 ohm speaker;
- amplifying transistor.
All the necessary details can be found in the old transistor type receiver. To assemble the control unit, you will need to find a suitable case and install all the parts.
The circuit and coil are connected together. using shielded wire. The cable screen is soldered to the coil terminal, insulation is installed, and the cable is fixed to the case with electrical tape.
Make the entry-level metal detector simply at home with the help of available tools. All that needs to be done is to follow the instructions and hardware assembly diagrams. The result is a model that can be used to search for small metal objects at a depth of 1 m.