Metal detectors or metal detectors are a diverse family of measuring instruments whose operation is based on differences in the electromagnetic radiation of objects.
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Using a metal detector
Professional highly sensitive metal detectors are used in the daily work of various inspection points, with their help search and inquiry actions of police and rescue services are conducted.
A huge army of amateur treasure hunters around the world practices long and leisurely trips with metal detectors. Sometimes such entertainment brings income and even fame.
Nowadays, the industry of detector (recognition) devices has already been established for all occasions, which differ not only in operating principles, but also in a wide range of prices and technical characteristics.
Simple magnetic detectors
The principle of operation of a simple metal detector is based on electromagnetic induction - an electromagnetic coil is located in the device, which, due to vibrations and distortions of its field, detects nearby electrically conductive and iron-magnetic materials, creating an audible or visual signal.
The first experience of assembling a metal detector at home can be the beginning of a serious hobby: new design solutions and even inventions in this field of applied radio electronics are not excluded even at an amateur level.
The diagram shows the structure of the simplest low-frequency magnetic detector.
In the manufacture of metal detectors, hundreds of different designs are used. In order to implement one of them yourself, you will need to make a printed circuit board with your own hands, purchase the necessary coils, transistors, resistors, capacitors, etc., and assemble the device.
Hand-held metal detector
Another option is to assemble a metal detector from improvised tools, is more suitable for humanities and novice techies with a passion for finding treasures and lost artifacts.
During the operation of such a home-made device, electromagnetic waves emitted by a calculator are caught on the AM range of the receiver.
An indicator of the location of an object in this device is the rotation of the electromagnetic field during re-emission, which changes the parameters of the sound signal. A photo of such a self-made metal detector can be found on the expanses of the network and at the end of our material.
To use such a prefabricated option, you need not a detailed diagram or assembly instruction, but compliance with certain requirements for the two main components of a home-made detector, namely, a calculator and a radio that are working properly.
Both devices should be of the cheapest category, the receiver should have an AM range and a magnetic antenna, and the calculator should emit pulsed radio noise during operation.
To work on the model, you will also need a suitable-sized plastic box with an opening lid, like a book, which will become the body of the finder.
For these purposes, the old box from CD discs is ideal. For fastening parts you will need double-sided tape.
Metal detector assembly
- Fastening devices inside the case: on the back of the devices a strip of tape is attached, then the calculator is located at the base of the box, the receiver is on the inside of the cover.
- Tuning the receiver: you need to turn on the receiver at maximum sound and select the upper position of the AM range, free from broadcasting radio stations and interference.
- Adjustment of the calculator: the receiver should react to the inclusion of the calculator with a sharp hum or buzz, if this is not the case, you need to adjust the range.
- Fixing the position: we begin to smoothly close the box to that position until the sound disappears or becomes more uniform and we fix the sash of the box in this position, using a foam cube, rubber bands, etc.
- The metal detector is ready. If there is a product with electromagnetic radiation nearby, the receiver will beep.
Combining the elements of other radio devices in a simple detector, you can observe in action the principle of operation of metal detectors and enjoy your first search expedition.
Note!
Such a detector, assembled at home, can be tested on the search for coins or metal construction debris lying in the surface layer of the earth in almost any area, on any open ground.
DIY metal detector photo
Note!
Note!
