Nowadays, many people are passionate about finding buried treasures, and sometimes even simple scrap metal. For some, this activity was an interesting pastime, and for someone - a means of earning.
The first model of an industrial metal detector was created in the 1960s and has found wide application in the mining sector and in other specially performed works.
Devices are used in mine clearance, forfinding weapons, in the exploration of geophysicists and archaeologists, when searching for treasure, as well as for finding foreign bodies of metal in food. In the construction industry, they are involved in detecting reinforcement in concrete blocks and pipelines in walls. Metal detectors also began to be used by miners and prospectors. And the improvement of the adaptation made it possible not to resort to excavation while finding gold.
Many people are interested in this device inover the past decades. 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
When asked what kind of device was the first, givean unequivocal answer is difficult, since at about the same time many inventors in different parts of the world carried out their own developments of the named unit.
But if we talk about one particular person,which can be considered the ancestor of the device, then this is undoubtedly the English geologist and mining engineer Fox. He discovered the property of passing electricity 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 the metal
The first search method was as follows:one rod of metal lay in the ground where the ore was supposed to be. It was connected to the same battery terminal. The other terminal was connected to the floating wire. Bars of metal 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. The wire connected through the battery, fell into the ground. Upon contact with the metal rang a bell.
Device "Pirate"
And now we look at modern devices.Some of them - "Pirate" - a metal detector that functions on the conductivity of electricity, inductive and magnetic properties of the metal. By the way, the device received its interesting name from the inventors: PI is the impulse principle of its operation, RAT is short for Radio Scot (the site of the inventors).
Metal Detector "Pirate", whose photopresented in this article has a unified construction. It includes a generator that produces alternating current that passes through a coil with a magnetic field. If the conductive metal is too close to the coil, the vortex flows will be directed towards the metal. This contributes to the formation of an alternating magnetic field in the metal. Detect the latter allows the use of another coil to measure the magnetic field.
Advantages of the device
«Пират» (металлоискатель) имеет простую the design and the unified setting does not contain the elements defined by the program that many hams are so afraid of. The device is perfect for beginners. And remember that he cannot distinguish between metals.
Metal detector "Pirate", the circuit board of whichrepresented by the NE555 microcircuit (the domestic analogue of KR1006VI1) does not contain expensive or difficult-to-get parts. Its technical parameters are in no way inferior to their foreign counterparts, the price of which reaches 300 y. e.
And the main advantages of this device over others are the stability of work and the response to metal from long distances.
Unified "Pirate" (metal detector forbeginners) has certain technical characteristics. Its power is 9-12 volts, and the level of energy consumed is 3-40 mA. The device senses objects as small as 150 cm.
Design
Transmitting and receiving are the main nodescomponents of the metal detector "Pirate". A printed circuit board, which is the model NE555 and a high-power switch on the IRF740 transistor, are included in the transmitting node. And the receiving node is assembled on the basis of the K157UD2 chip and the BC547 transistor.
The coil winding is carried out on a mandrel with a diameter of 190 mm and contains 25 turns of the PEV 0.5 wire.
NPN bipolar transistor replaced T2 model andhas 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 NPN transistor.
Properly assembled device does not need additional configuration. You may have to resort to the use of resistor R12, so that the clicks during movement appear in the middle position of R13.
With an oscilloscope you cancontrol of the duration of the control pulse at the T2 gate and the level of the generator frequency. The optimal pulse duration is 130-150 μs, and the frequency is 120-150 Hz.
How to work with the device
After turning on the device "Pirate"(metal detector) you should wait 15 or 20 seconds, after which a position is set by means of the sensitivity adjuster, in 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.
Metal detector "Pirate" do it yourself
Many ask the question: how to make a metal detector "Pirate" independently? Assembling such a unit under the force of people with elementary knowledge in the field of electronics.
Pulse metal detector "Pirate" has the mostnormal and accessible to copy design. The device contains a number of components and an easy-to-perform search coil. If its diameter is 280 mm, then it can detect objects ranging in size from 20 to 150 cm.
Изготовление металлоискателя «Пират» своими hands - the task is not difficult, which is a huge advantage of this device. Assembly components are available and easily located. They cost absolutely cheap. You can buy them in the parts store for radio or on the market.
List of necessary parts for manufacturing
Let's try to collect the metal detector "Pirate" with their own hands. Detailed instructions will help even inexperienced amateurs to do this without errors.
The device has two schematic modifications.In the first case, the NE555 chip (the domestic analog of the chip - KR1006VI1) is used - the timer. But if you could not get this component, then the authors provided another version of the circuit, based on transistors.
But it is still recommended to assemble the device on the basis of the first scheme, since it is more stable in operation.
When building on the basis of transistors shouldselect the desired frequency and duration, as they have a fairly large range of technical characteristics. To this end, resorting to the use of an oscilloscope.
PCB device
Homemade metal detector "Pirate" has several options for the layout of the printed circuit board, but most often use the board series "Spring Layot."
After soldering it connects to power.For this purpose, use any power source with a voltage of 9-12 volts. You can resort to using batteries "Krona" (3 or 4 pieces) or battery. The use of one "Crown" is not recommended, since this will cause a rapid voltage drop, which, in turn, will entail a constant freezing of the device settings.
Manufacturing coils for the metal detector "Pirate"
Like other models of impulse devices forfinding the 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 the mandrel, with a diameter of 190-200 mm - 25 turns. When this is used winding enameled wire with a cross section of 0.5 mm.
The coils of the coil are wrapped byinsulating tape or scotch tape. By the way, to increase the depth of the search device, you can resort to the winding of the named part, with a diameter of 260-270 mm, 21-22 turns with the same wire.
Coil fixture is fixed in solidcase, which must be made, for example, from plastic. This is necessary in order to protect the device from hitting the ground or the grass while the machine is running. Such a body can be purchased at online stores. In general, in the manufacture of coils for the search, the use of metal parts is not recommended.
The findings of the mentioned parts are soldered to the stranded wire with a cross section of 0.5 - 0.75 mm. Ideally, these are two separate stranded wires. Your device is ready!
Reviews
Available on the metal detector "Pirate" reviewsindicate that it has become very popular with users. According to them, the device has a high degree of functionality, and finds things from metal in a short time and without the presence of errors. It is easy to apply and does not feel in your hand.
The finished device is assembled from several partswhich are easily compiled. The lower part is its foundation. The system works with the device is extremely clear. Setting the metal detector "Pirate" is no difficulty.
