Nowadays, many people are passionate about finding buried treasures, and sometimes simple scrap metal. For some, this occupation has become an interesting pastime, and for someone - a means of earning.
The first model of an industrial metal detector was created in the 1960s and found wide application in the mining sector and in other specially conducted operations.
The devices are used in mine clearing, for finding weapons, in the exploration of geophysicists and archaeologists, when searching for treasures, and also for finding foreign bodies made of metal in food. In the construction industry, they are used to detect reinforcement in concrete blocks and pipelines in the walls. Metal detectors also began to be used by miners and prospectors. And the improvement of the device made it possible not to resort to excavations when finding gold.
Many people have become interested in this device over the past decades. The search for treasures and scrap metal has become a popular hobby. Some, for example, go with such a device on the beach, hoping to find a valuable thing.
Who invented the metal detector
It is difficult to give an unequivocal answer to the question which particular device was the first, since at about the same time many inventors in different parts of the world carried out their own development of the named unit.
But if we talk about one specific person who can be considered the ancestor of the device, then this is undoubtedly an English geologist and mining engineer Fox. He discovered the property of electricity passing through metal ores and objects. Around 1830, he developed the first unified locator, which included a battery, several metal rods and wires of suitable length.
The first methods of finding metal
The first search method was as follows: one rod of metal lay in the ground where the ore was supposed. It connected to one battery terminal. Another terminal connected to a floating wire. The metal rods were driven into the ground at various points and consistently touched the wire. When a metal object was found, sparks appeared.
In 1870, two separate rods were used in the device. A wire connected through a battery sank to the ground. Upon contact with the metal, a warning bell rang.
Fixture "Pirate"
And now we will consider modern appliances. One of them is โPirateโ - a metal detector that operates on the conductivity of electricity, the inductive and magnetic properties of the metal. By the way, the device got its interesting name from the inventors: PI - the pulse principle of its operation, RAT - short for "Radio Scot" (the website of the inventors).
The Pirate metal detector, the photo of which is presented in this article, has a unified design. It includes an alternating current generator that passes through a magnetic field coil. If the metal conducting current is too close to the coil, then the vortex flows will be directed to the metal. This contributes to the formation of an alternating magnetic field in the metal. Detecting the latter makes it possible to use another coil to measure the magnetic field.
Advantages of the device
The "pirate" (metal detector) has a simple design and unified configuration, does not contain the elements set by the program that many radio enthusiasts are so afraid of. The device is perfect for beginners. And remember that he cannot distinguish between metals.
The Pirate metal detector, the printed circuit board of which is represented by the NE555 microcircuit (the domestic analogue of KR1006VI1) does not contain expensive or hard-to-reach parts. Its technical parameters are in no way inferior to foreign analogues, the price of which reaches 300 c. e.
And the main advantages of this device over others are stability of work and response to metal from a long distance.
The unified "Pirate" (a metal detector for beginners) has certain technical characteristics. Its power supply is 9-12 volts, and the level of energy consumption is 3-40 mA. The device senses objects up to 150 cm in size.
Design
The transmitter and receiver are the main components that make up the Pirate metal detector. The printed circuit board, which is the NE555 model and a high power key on the IRF740 transistor, are included in the transmitting node. And the receiving unit is assembled on the basis of the K157UD2 chip and the BC547 transistor.
Coil winding is carried out on a mandrel with a diameter of 190 mm and contains 25 turns of PEV 0.5 wire.
The NPN bipolar transistor replaced the T2 model and has a voltage of at least 200 volts. It can be taken from an economical lamp or a device for charging a mobile phone. In extreme cases, T2 can be replaced by KT817.
As T3, you can use any type of transistor NPN circuit.
A properly assembled device does not need additional configuration. You may have to resort to the use of resistor R12, so that clicks when moving appear in the middle position of R13.
With an oscilloscope, you can control the duration of the control pulse on the gate T2 and the frequency level of the generator. The optimal pulse duration is 130-150 ฮผs, and the frequency is 120-150 Hz.
How to work with the device
After turning on the Pirate device (metal detector), you should wait 15 or 20 seconds, after which the sensitivity adjuster sets the position at which clicks are heard during movement. This will serve as an indicator of maximum sensitivity.
The device has a unified control system, so the acquisition of skills to work with it is not so difficult.
Do-it-yourself metal detector "Pirate"
Many people ask themselves: how to make a Pirate metal detector yourself? Assembling such an assembly is possible for people with basic knowledge in the field of electronics.
Pulse metal detector "Pirate" has the most common and affordable design for copying. The device contains a number of components and a search coil that is easy to carry out. If its diameter is 280 mm, then it can detect objects ranging in size from 20 to 150 cm.
Making a Pirate metal detector with your own hands is not a difficult task, which is a huge advantage of this device. Assembly components are available and easy to install. They are very cheap. You can buy them in the radio parts store or on the market.
List of necessary parts for manufacturing
Let's try to assemble the Pirate metal detector with our own hands. Detailed instructions will help even inexperienced hams to do this without errors.
The device has two schematic modifications. In the first case, the NE555 chip is used (the domestic analogue of the chip is KR1006VI1) - a timer. But if you could not get this component, then the authors provided for another version of the circuit based on transistors.
But nevertheless, it is recommended to assemble the device based on the first scheme, since it has greater stability during operation.
When assembling based on transistors, you need to choose the right frequency and duration, since they have a fairly large spread of technical characteristics. To this end, resort to the use of an oscilloscope.
Instrument circuit board
A homemade Pirate metal detector has several options for wiring a printed circuit board, but most often they use the Spring Layot series circuit board .
After soldering, power is connected to it. For this purpose, any power source with a voltage indicator of 9-12 volts will be used. You can resort to using batteries "Krona" (3 or 4 pieces) or the battery. The use of one "Krona" is not recommended, as this will cause a rapid decrease in voltage, which, in turn, will lead to a constant hang of the device settings.
Manufacture of a coil for the Pirate metal detector
Like other models of pulse devices for finding metal, the device is undemanding to accuracy in the manufacture of the coil. It is quite acceptable to use the one that is wound on a mandrel with a diameter of 190-200 mm - 25 turns. In this case, a winding enameled wire with a cross section of 0.5 mm is used.
The turns of the coil are wrapped with an insulating tape or tape. By the way, to increase the depth of the device search, you can resort to the winding of the named part, with a diameter of 260-270 mm, 21-22 turns in the same wire.
The coil of the device is fixed in a solid case, which must be made, for example, of plastic. This is necessary in order to protect the device from blows to the ground or grass during operation of the unit. Such a case can be purchased at online stores. In general, in the manufacture of search coils, the use of metal parts is not recommended.
The findings of the mentioned parts are soldered to a stranded wire with a cross section of 0.5 - 0.75 mm. Ideally, these are two separate interwoven wires. Your appliance is ready!
Reviews
The reviews available on the Pirate metal detector indicate that it has become very popular with users. According to them, the device has a high degree of functionality, and finds things made of metal in a short time and without any errors. It is easy to use and is not felt in the hand.
The finished device is assembled from several parts, which are easily assembled. The lower part is its foundation. The system of working with the device is extremely clear. Setting up the Pirate metal detector is no problem.