A simple and reliable DIY metal detector. Homemade metal detectors, or how to make a metal detector with your own hands. How to make a metal detector with your own hands with metal discrimination

The number of treasure hunters is growing steadily. And although everything has long been dug up, there are still enthusiasts who want to try their luck and go on another search for gold, antiques or coins. This is not strange, because the procedure itself has a unique atmosphere and gives each participant a lot of unforgettable emotions. It is enough to charge the batteries, drive away from the city, make the first couple of swings of the coil and wait for the sound signal about the find. Here it is, the secret of every treasure hunter’s good mood.

Currently, there is a large selection of instruments for detecting metals. It’s easy to find models on sale that cost less than a hundred dollars. But besides this, there are also expensive products that sell for over $1,000. Does it make sense for a beginner to buy such an expensive device? Of course not. The more expensive the device, the more difficult it is to set up. Naturally, a novice digger will not be able to understand all the possibilities of such an invention without having the appropriate experience and minimal skills. Or maybe try to make a simple metal detector with your own hands? After all, this is a completely doable procedure and anyone can do it.

How to make a metal detector with your own hands

Before you make a simple metal detector at home, you should understand principle of its operation.

A metal detector (metal detector, metal scanner, etc.) is a special device for quickly identifying metal objects underground. There are several types of such inventions available on the market, each with different characteristics and capabilities. To a large extent, the key differences lie in detection depth and ease of use. Naturally, the deeper the device “sees,” the more expensive it will cost.

The principle of operation is based on the use of the law of magnetic attraction of objects. The device generates a magnetic field and sends it to a specific area underground. If there is any object with metallic properties there, a signal is displayed from it and returns back, notifying the treasure hunter of the find.

To build a high-frequency instrument you need to assemble high quality command block. It is used as a laptop or radio, on which maximum frequency AM. First make sure that the wave is “clean” and there are no radio stations on it.

The next step involves creating a search head, which is easy to make from a thin sheet of plywood. We cut out two circles with a diameter of 15 and 10 centimeters and secure them tightly together.

Then you need to cut sticks out of wood to position the rings parallel to each other. It is necessary to wrap the plate with enameled copper wire, making 10-15 turns. After this, the fake can be attached directly to the block itself. We launch the highest frequency. If the procedure is successful, you will hear a low tone. For clearer playback, it is better to use an external speaker or headphones. Installing a metal detector according to these instructions is very simple. In addition, on the Internet you can download training videos and diagrams for performing the action.

DIY metal detector: diagram

Finding circuits for a simple metal detector with discrimination support is very simple. To make a device, you need to stock up:

For making a coil with a diameter of 90 millimeters, you need to wrap cardboard circles with copper wire, making 250 turns. If we are talking about a coil with a diameter of 70 mm, then here you will have to make 290 turns. As a result, it will be possible to obtain 10 mH.

After you assemble the circuit, you need to make sure it works. After this, you can begin manufacturing the printed circuit board, where all other elements of the metal detector will be installed.

The next step involves preparing the handle. It can be made from cardboard by cutting out three identical blanks in the shape of a boomerang. It is necessary to cut holes in the handle for the batteries, after which three separate ones can often be fixed together with glue. You should also cut out a space for the on/off button. After attaching the circuit, battery and switch, the coil can be completed.

DIY metal detector made from DVDs

You can make a simple metal detector with your own hands using two CDs and a DVD. The instructions are particularly simple and do not require the use of additional diagrams or complex instructions. All that is required for production is:

Calculator. It doesn’t matter what type of device you get your hands on. You can take the most simple and cheap model;

1. Headphones;
2. Battery "Krona";
3. Glue and a roll of electrical tape;

Sequencing when creating a metal detector from DVDs:

• Take the headphones and cut off the plug.
• Then you need to strip 10 centimeters of insulating wire and divide it into two to get two pairs of wires;
• After this, you should attach one wire from a pair to the disk. If you are using a single-sided disc, you need to attach it to the writing side;
• We fix the wires with electrical tape, and connect the rest of the “bare” part to the battery, to the plus and minus contacts.
• At the next stage, you need to carefully insulate the exposed cable;
• We tightly attach a previously turned on and charged calculator to the surface of the CD;
• Then you need to place a DVD on it, and at the final stage wrap the structure with electrical tape;
• At the final stage, it is necessary to fix the Krona battery on the surface of the disk;

That's all, the circuit of the simplest but very effective metal detector is ready. All that remains is to test it in real conditions and make sure that everything works without failures. Of course, you won’t be able to search for coins at a depth of half a meter with such a device, but still, it is quite suitable for home use.

DIY metal detector “Pirate”

Among homemade metal detectors, it is especially in demand. option called "Pirate". Pirate is a pulse metal detector, which is built on a simple and accessible circuit. The design uses several small elements and a small coil. If you equip the device with a coil with a diameter of 280 mm, then it will be able to “see” coins at a depth of up to 20 centimeters. The device will find large metal objects even at a depth of one and a half meters.

The name “Pirate” (PIRAT) comes from the developers of the scheme - PI - denotes the principle of operation, and RAT - is an abbreviation for “Radio Scott” - the developers’ site.

The homemade Pirate device is not capable of discriminating between metals. But to search for large objects It will do just fine. Such a device is especially valued among novice metal detectors. Everything is determined by ease of use and good search results. You can find diagrams and buy components for creating a “Pirate” at any market or in a store of parts for radios and other radio equipment. To manufacture such a device it is not necessary to have high level preparation.

In the end, we can say with confidence that it is quite possible to assemble a metal detector with your own hands at home. To do this, you should study the detailed instructions and understand the manufacturing diagram. It is important to understand that homemade devices are not suitable for more serious searches, for example, coins or small antiques. This is due to the small range. In any case, making a metal detector with your own hands will allow you to create a very good device that will be suitable for acquiring the initial skills of a real treasure hunter.

Many people unreasonably believe that homemade metal detectors are inferior in many respects to branded samples produced at the factory.

But in fact, structures that are correctly assembled with your own hands sometimes turn out to be not only better, but also cheaper than “factory” competitors.

Worth knowing: Most treasure hunters and local historians, in order to save money, try to choose the cheapest options. As a result, they either assemble metal detectors themselves or purchase homemade custom devices.

Beginners, as well as people who do not understand electronics, are at first intimidated by the abundance of not only special terminology, but also various formulas and circuits. However, if you delve a little deeper, everything immediately becomes clear, even with the knowledge gained in school physics lessons.

Therefore, it is worth, first of all, to understand the principle of operation of a metal detector, what it is and how you can assemble it yourself at home.

How does it work

The operating principle of this device is to use an electromagnetic field. It is created by the transmitter coil and after a collision with an object that conducts current (which is most metals), eddy currents are created that introduce distortion into the EPM of the coil.

In cases where the object is not electrically conductive, but has its own magnetic field, the interference it creates will also be captured due to shielding.

After this, changes in the electromagnetic field are sent directly to the control unit, which emits a special signal to notify that a person has been found. sound signal, and in more expensive models displays data on the display.

It is worth examining how such devices are created following the example of a “Pirate” type metal detector.

Metal detector "Pirate"

Making a printed circuit board with your own hands

First you need to create a printed circuit board, where all the nodes of the metal detector will be located in the future. The best method is laser-iron technology or simply LUT.

To do this, it will be necessary to perform the manufacturing steps in the following sequence:

1. First, using only a laser printer, you need to print the corresponding diagram created through the Sprint-Layout program. It is best to use light weight photo paper for this.
2. We prepare the PCB workpiece, first sand it, and then clean it with a solution. It should have dimensions 84x31.
3. Now on top of the blank we place photo paper with the diagram on the front side on which it was printed. Cover with an A4 sheet and begin ironing with a hot iron in order to transfer the marking scheme to the textolite.
4. After fixing the circuit from the toner, we place it all in water, where we carefully remove the paper with our fingers.
5. Next, if there are smeared areas, we correct them using a regular needle.
6. Now the board needs to be placed in a solution of copper sulfate for several hours (ferric chloride can also be used).
7. The toner can be removed without any problems with any solvent, such as acetone.
8. We drill holes for later placement of structural elements (the drill must be very thin).
9. The last stage is to lay out the board tracks. To do this, a special solution “LTI-120” is smeared on the surface, which needs to be spread over the solder of the soldering iron.

Installing elements on the board

This stage of creating a metal detector consists of installing all the elements on the created board:

1. The main microcircuit is the domestic KR1006VI1 or its foreign analogue NE555. Please note that before installation, a jumper must be soldered underneath it.
2. Next, a two-channel amplifier K157UD2 is installed. You can buy it or take it from Soviet tape recorders.
3. After this, 2 SMD capacitors are mounted, as well as one resistor of the MLT C2-23 type.
4. Now you need to solder two transistors. One must be NPN structure, and the other PNP. It is advisable to use BC557 and BC547. However, analogues will also work. It is recommended to use IRF-740 or other options with similar characteristics as a field-effect transistor.
5. The capacitors are installed last. They should be taken with a minimum TKE indicator, which will increase the thermal stability of the entire structure.

Note: The hardest thing will be to get the K157UD2 amplifier out of this circuit. The reason is that it is already an old chip. That is why you can try to find similar modern options with similar parameters.

A homemade coil is created on a frame with a diameter of 20 cm. The total number of turns should be approximately 25 pieces. This indicator is based on the fact that PEV wire is used, which has a diameter of 0.5 mm.

However, there is a certain peculiarity. The total number of turns can be changed up or down. To find the most optimal option, you need to take a coin and check in which case there will be the longest distance to “catch” it.

Other elements

A signal speaker can be used taken from a portable radio. It is important that it has a resistance of 8 ohms (Chinese options can be used).

To carry out the adjustment, you will need two potentiometer models of different power: the first is 10 kOhm, and the second is 100 kOhm. To minimize the influence of interference (it will be difficult to eliminate it completely), it is recommended to use a shielded wire that will connect the circuit and the coil. The metal detector's power source must be at least 12 V.

When the entire structure has been tested for functionality, it is necessary to make a frame for the future metal detector. However, here we can only give some recommendations, because everyone will create it from the items at hand:

• to make the bar more convenient, it is worth purchasing 5 meters of ordinary PVC pipe (which are used in plumbing), as well as several jumpers. It is worth installing a special palm rest at its upper end to make it more comfortable to hold. For the board, you can find any box of the appropriate size that needs to be mounted on the rod;
• To power the system, you can use a battery from a regular screwdriver. Its advantages are low weight and high capacity;
• When creating the body and structure, keep in mind that there should not be any unnecessary metal elements in them. The reason is that they significantly distort the resulting electromagnetic field of the future device.

Checking the metal detector

First of all, you need to adjust the sensitivity using potentiometers. The threshold will be a uniform, but not very frequent, crackling.

So, he will have to “find” a five-ruble coin from a distance of approximately 30 cm, but if the coin is the size of a Soviet ruble, then from about 40 cm. He will “see” large and voluminous metal from a distance of more than a meter.

Such a device will not be able to search for small objects at significant depths. In addition, he will not be able to distinguish between the size and type of metal found. That is why, while searching for coins, you may come across ordinary nails.

This model of homemade metal detector is suitable for people who are just starting to learn the basics of treasure hunting or do not have the necessary funds to purchase an expensive device.

Their this video You will learn how to make a homemade metal detector:

Deep-type metal detectors are capable of detecting objects in the ground at a great distance. Modern modifications in stores are quite expensive. However, in this case, you can try to make a metal detector with your own hands. For this purpose, it is first recommended to familiarize yourself with the design of the standard modification.

Modification scheme

When assembling a metal detector with your own hands (the diagram is shown below), you need to remember that the main elements of the device are a damper on a microcontroller, a capacitor and a handle with a holder. The control unit in the devices consists of a set of resistors. Some modifications are made on drive modulators that operate at a frequency of 35 Hz. The racks themselves are made with narrow and wide plate-shaped plates.

Assembly instructions for a simple model

Assembling a metal detector with your own hands is quite simple. First of all, it is recommended to prepare a tube and attach a handle to it. High conductivity resistors will be required for installation. The operating frequency of the device depends on many factors. If we consider modifications based on diode capacitors, then they have high sensitivity.

The operating frequency of such metal detectors is about 30 Hz. Their maximum object detection distance is 25 mm. Modifications can operate on lithium batteries. Microcontrollers for assembly will need a polar filter. Many models fold on open-type sensors. It is also worth noting that experts do not recommend using high sensitivity filters. They greatly reduce the accuracy of detecting metal objects.

Model series "Pirate"

You can make a “Pirate” metal detector with your own hands only using a wired controller. However, first of all, a microprocessor is prepared for assembly. To connect it you will need Many experts recommend using grid capacitors with a capacity of 5 pF. Their conductivity should be maintained at 45 microns. Afterwards you can start soldering the control unit. The stand must be strong and support the weight of the plate. For 4 V models, it is not recommended to use plates with a diameter larger than 5.5 cm. System indicators do not need to be installed. After securing the unit, all that remains is to install the batteries.

Using reflex transistors

Making a metal detector with reflex transistors with your own hands is quite simple. First of all, experts recommend installing a microcontroller. In this case, capacitors are suitable of a three-channel type, and their conductivity should not exceed 55 microns. At 5 V they have a resistance of approximately 35 ohms. Resistors in modifications are mainly used of the contact type. They have negative polarity and cope well with electromagnetic vibrations. It is also worth noting that during assembly it is allowed to use the maximum width of the plate for such a modification is 5.5 cm.

Model with convection transistors: expert reviews

You can assemble a metal detector with your own hands only on the basis of a collector controller. In this case, capacitors are used at 30 microns. If you believe the reviews of experts, then it is better not to use powerful resistors. In this case maximum capacity elements should be 40 pF. After installing the controller, it is worth working on the control unit.

These metal detectors receive good feedback for reliable protection against wave interference. For this purpose, two diode-type filters are used. Modifications with display systems are very rare among homemade modifications. It is also worth noting that power supplies must operate at low voltage. This way the battery will last for a long time.

Using Chromatic Resistors

With your own hands? The model with chromatic resistors is quite simple to assemble, but it should be taken into account that capacitors for modifications can only be used on fuses. Experts also point out the incompatibility of resistors with pass filters. Before starting assembly, it is important to immediately prepare a tube for the model, which will be the handle. Then the block is installed. It is more advisable to select modifications at 4 microns, which operate at a frequency of 50 Hz. They have a low dispersion coefficient and high measurement accuracy. It is also worth noting that searchers of this class will be able to successfully work in conditions of high humidity.

Model with a pulse zener diode: assembly, reviews

Devices with pulsed zener diodes are distinguished by their high conductivity. If you believe the reviews of experts, then homemade modifications can work with objects different sizes. If we talk about the parameters, their detection accuracy is approximately 89%. You should start assembling the device with a stand blank. Then the handle for the model is mounted.

The next step is to install the control unit. Then a controller is mounted, which runs on lithium batteries. After installing the unit, you can start soldering the capacitors. Their negative resistance should not exceed 45 ohms. Expert feedback indicates that modifications of this type can be produced without filters. However, it is worth considering that the model will have serious problems with wave interference. In this case, the capacitor will suffer. As a result, the battery of models of this type quickly discharges.

Application of low frequency transceiver

Low-frequency transceivers in models significantly reduce the accuracy of the devices. However, it is worth noting that modifications of this type can successfully work with small objects. At the same time, they have a low self-discharge parameter. In order to assemble the modification yourself, it is recommended to use a wired controller. The transmitter is most often used with diodes. Thus, conductivity is ensured at around 45 microns with a sensitivity of 3 mV.

Some experts recommend installing mesh filters, which increase the security of models. To increase conductivity, only transition type modules are used. The main disadvantage of such devices is considered to be controller burnout. If such a breakdown occurs, it is problematic to repair the metal detector yourself.

Using a High Frequency Transceiver

On high-frequency transceivers, you can assemble a simple metal detector with your own hands only on the basis of an adapter controller. Before installation, a stand for the plate is prepared as standard. The average conductivity of the controller is 40 microns. Many specialists do not use contact filters during assembly. They have high thermal losses and are capable of operating at 50 Hz. It is also worth noting that lithium batteries are used to assemble the metal detector, which recharge the control unit. The sensor itself in modifications is installed through a capacitor, the capacitance of which should not exceed 4 pF.

Model with longitudinal resonator

Devices with longitudinal resonators are often found on the market. They stand out among their competitors by their high accuracy in identifying objects, and at the same time they can work in high humidity. In order to assemble the model yourself, a stand is prepared, and a plate should be used with a diameter of at least 300 mm.

It is also worth noting that to assemble the device you will need a contact controller and one expander. Filters are used only on mesh lining. Many experts recommend installing diode capacitors that operate at a voltage of 14 V. First of all, they discharge little of the battery. It is also worth noting that they have good conductivity compared to field analogues.

Using selective filters

Making such a deep metal detector with your own hands is not easy. The main problem is that a regular capacitor cannot be installed in the device. It is also worth noting that the plate for modification is selected from 25 cm in size. In some cases, the racks are installed with an expander. Many experts advise starting assembly by installing the control unit. It must operate at a frequency of no more than 50 Hz. In this case, the conductivity depends on the controller used in the equipment.

Quite often it is selected with a lining to increase the security of the modification. However, such models often overheat and are not able to work with high accuracy. To solve this problem, it is recommended to use conventional adapters that are installed under the capacitor units. A do-it-yourself metal detector coil is made from a transceiver block.

Application of contactors

Contactors are installed in devices together with control units. Stands for modifications are used of short length, and plates are selected at 20 and 30 cm. Some experts say that devices should be assembled on impulse adapters. In this case, capacitors can be used with low capacitance.

It is also worth noting that after installing the control unit, it is worth soldering a filter that can operate at a voltage of 15 V. In this case, the model will maintain a conductivity of 13 microns. Transceivers are most often used on adapters. Before turning on the metal detector, the level of negative resistance is checked on the contactor. The specified parameter is on average 45 Ohms.

Metal detector circuit

Today I would like to present to your attention a diagram of a metal detector, and everything related to it, what you see in the photograph. After all, it is sometimes so difficult to find the answer to a question in a search engine - Diagram of a good metal detector

In other words, the metal detector has a name Tesoro Eldorado

The metal detector can operate in both the search mode for all metals and background discrimination.

Technical characteristics of the metal detector.

Operating principle: induction balanced
-Operating frequency, kHz 8-10kHz
-Dynamic operating mode
-Precise detection mode (Pin-Point) is available in static mode
-Power supply, V 12
-There is a sensitivity level regulator
-There is a threshold tone control
-Ground adjustment is available (manual)

Detection depth in the air with a DD-250mm sensor In the ground, the device sees targets almost the same as in the air.
-coins 25mm - about 30cm
-gold ring - 25cm
-helmet 100-120cm
-maximum depth 150cm
-Consumption current:
-No sound approximately 30 mA

And the most important and intriguing thing is the diagram of the device itself

The picture is easily enlarged when you click on it

To assemble the metal detector you need the following parts:

So that you don’t have to spend a long time setting up the device, do the assembly and soldering carefully; the board should not contain any clamps.

For tinning boards, it is best to use rosin in alcohol; after tinning the tracks, do not forget to wipe the tracks with alcohol

Parts side board

We begin assembly soldering jumpers, then resistors, further sockets for microcircuits And all the rest. One more small recommendation, now regarding the manufacture of the device board. It is very desirable to have a tester that can measure the capacitance of capacitors. The fact is that the device These are two identical amplification channels, therefore the amplification through them should be as identical as possible, and for this it is advisable to select those parts that are repeated on each amplification stage so that they have the most identical parameters as measured by the tester (that is, what are the readings in a particular stage on one channel - the same readings on the same stage and in another channel)

Making a coil for a metal detector

Today I would like to talk about the manufacture of a sensor in a finished housing, so the photo is more than words.
We take the housing, attach the sealed wire in the right place and install the cable, ring the cable and mark the ends.
Next we wind the coils. The DD sensor is manufactured according to the same principle as for all balancers, so I will focus only on the required parameters.
TX – transmitting coil 100 turns 0.27 RX – receiving coil 106 turns 0.27 enameled winding wire.

After winding, the coils are tightly wrapped with thread and impregnated with varnish.

After drying, wrap tightly with electrical tape around the entire circumference. The top is shielded with foil; between the end and the beginning of the foil there should be a gap of 1 cm not covered by it, in order to avoid a short-circuited turn.

It is possible to shield the coil with graphite; to do this, mix graphite with nitro varnish 1:1 and cover the top with a uniform layer of tinned copper 0.4 wire wound on the coil (without gaps), connect the wire to the cable shield.

We put it into the case, connect it and roughly bring the coils into balance, there should be a double beep for the ferrite, a single beep for the coin, if it’s the other way around, then we swap the terminals of the receiving winding. Each of the coils is adjusted in frequency separately; there should be no metal objects nearby!!! The coils are tuned with an attachment for measuring resonance. We connect the attachment to the Eldorado board in parallel with the transmitting coil and measure the frequency, then with the RX coil and a selected capacitor we achieve a frequency 600 Hz higher than that obtained in TX.

After selecting the resonance, we assemble the coil together and check whether the device sees the entire VDI scale from aluminum foil to copper; if the device does not see the entire scale, then we select the capacitance of the resonant capacitor in the RX circuit in steps of 0.5-1 nf in one direction or another, and in addition the moment when the device will see foil and copper at a minimum of discrimination, and when the discrimination is turned up, the entire scale will be cut out in turn.

We finally reduce the coils to zero, fixing everything with hot glue. Next, to lighten the coil, we glue the voids with pieces of polystyrene foam, the foam sits on the hot glue, otherwise it will float up after filling the coil.

Pour the first layer of epoxy, without adding to the top 2-3mm

Fill in the second layer of resin with color. An aniline dye is a good choice for dyeing fabric; the powder comes in different colors and costs a penny. The dye must first be mixed with the hardener, then the hardener must be added to the resin; the dye will not dissolve in the resin immediately.

To assemble the board correctly, start by checking the correct power supply to all components.

Take the circuit and the tester, turn on the power on the board, and, checking the circuit, go through the tester at all points on the nodes where power should be supplied.
When the discrimination knob is set to minimum, the device should see all non-ferrous metals

, when screwing the discrim, they should be cut out

all metals in order up to copper should not be cut out if the deviceit works this way, which means it is configured correctly. The discrimination scale needs to be selected so that it fits completely into a full turn of the discrimination knob, this is done by selecting c10. When the capacity decreases, the scale stretches and vice versa.

There is probably no need to tell you what this electronic device is intended for. Everything is clear to everyone. These devices are used by sappers, at airports, in intelligence agencies, and in various institutions related to security in one way or another. But that is not all.

Metal detector in the 90s

These devices in the 90s of the twentieth century helped people not to die of hunger. During those difficult times, you could often see young people and others walking the streets with metal detectors. The device was used to search for metals and alloys. In particular, in cities near which large industries were located, it was possible to dig up real wealth with its help.

Basically, these guys made metal detectors with their own hands and looked for waste from metallurgical plants or native metals that remained in the bowels of the earth. The latter were used in the construction of routes. After all, many asphalt and dirt roads were covered with slag, and often in its composition one could find metal and an alloy of iron and manganese - ferromanganese. At the end of the 90s, it had already become quite expensive. In one day of such work on city and country roads one could earn as much as a factory worker earned in a week. Since many people were unemployed, this activity became especially popular. After all, this alloy is one of the components for creating steel of various grades at the same metallurgical plants.

Metal detectors today

Today the topic of searching with the help electronic devices not so widely developed. However, these devices are still popular among certain groups of people. They wander through the places of former glory of valiant Soviet soldiers, trying to dig up something valuable from historical objects. For example, you can find coins from the time of the Patriotic War, German ones of course. And some people manage to dig up really valuable things. You just need to know where to look.

What can you really find?

Unless you pick up the device yourself and walk along the city roads or through memorable and historical places, you will hardly believe how many interesting objects the earth stores. And for this you should build a metal detector with your own hands.

Coins

Often you can dig them up. During the times of Ancient Rus', coins of the Arab East were used for trade. Then they used coins of Byzantine and Tatar production. Silver bullion is now found in the form of money.

Today in Crimea (and this is where well-preserved objects can be found) you can see people with these devices.

Crosses, icons, coils

Every self-respecting Christian wore a cross in Ancient Rus'. All crosses were different from each other, depending on the type and its purpose. You can often find so-called vests.

Buckles, buttons, various household items

This group of items is very numerous. Most of them have been used since the Bronze Age and are still used today. Often the objects were made of bronze, copper or iron.

Echoes of War

This is the most popular group of items that are searched for purposefully. They are especially popular among collectors. Enthusiasts are searching, getting them, and restoring them. Some end up in museums, some end up in your hands.

How to make a metal detector with your own hands

In the era of the popularity of ferromanganese and high prices for it, grimy young people did not shy away from digging in the ground to earn a little money. More often they purchased devices to search for their prey in numerous markets or from various specialists who, by chance, were fired from radio factories or TV repair shops. One way or another, these professionals assembled the metal detector with their own hands from radio components left in stores using various schemes and technologies. The guys often argued about who had the better and more technologically advanced device. After all, back then it was actually a working tool, and not a hobby device, as it is nowadays.

Those who had at least a little knowledge of electronics also made their own metal detectors. But these guys weren't interested in digging a metallurgical ingredient out of the ground. But it seems we have deviated from the topic.

Principle of operation

Before moving on to assembling various circuits, you need to look at the operating principle of these devices.

The operation of a metal detector is based on the principles of magnetic attraction. The device creates a magnetic field through one coil. The second receives return signals. Then, if found, it sends a return signal through an audible alarm. You can even make a special metal detector for non-ferrous metals with your own hands.

The larger the coil, the more sensitive the device will be. Although in modern devices, and especially in industrial models, the coil is small. But there are amplifiers on microcircuits.

Types

An ultra-low frequency finder is the simplest device. Every schoolchild knows how to make a metal detector with his own hands using an ultra-low frequency circuit. But this does not mean that such a seeker is ineffective. Just the opposite. With proper setup, you can achieve good results.

The pulse finder is a deeper device. With its help you can easily find jewelry, coins and other small items at great depths. Such schemes are popular among professional treasure hunters.

A device that operates on beats allows you to detect absolutely any metal object or mineral in the bowels of the earth at a depth of up to a meter. It is designed for certain types of alloys. This is a cheap device to assemble.

The radio detector is capable of detecting metals at a depth of up to a meter. It's easy to do. This is a suitable device for beginners, but is not popular among diggers.

A primitive metal detector using one transistor

If you still have a long-wave radio receiver in working condition at home, then even if you have little knowledge of electronics, you can assemble a metal detector attachment for this receiver.

To make a metal detector with your own hands, the diagram is drawn without much difficulty. The circuit diagram represents the most common LC generator, designed for frequencies in the region of 140 KHz. The coil for the device, which is used as an oscillating circuit, should contain 16 turns of the simplest insulated wire up to 0.5 mm in diameter. The coils must be laid on plywood of suitable sizes. Fix the resulting contour to the base using glue. This is how you usually make a coil for a metal detector with your own hands.

Required Parts

You can use absolutely any resistors and capacitors for this device. As a transistor, a low-power high-frequency one with reverse conductivity will suffice. This could be the popular and easily available KT315. Or KT3102 with any letter index.

To assemble this simple metal detector with your own hands, the circuit is assembled either by surface mounting or on a pre-prepared board made of getinax or textolite.

Setting up a simple metal detector

After the part is ready, we need to place it next to our coil. The device should have a comfortable handle. The radio receiver must be mounted on the finder handle, and then tuned to a frequency around 140 kHz. You will hear a squeak or squeak. If you bring the coil closer to a metal object, the sound in the headphones will change its tone.

Despite the fact that these are the simplest metal detectors in design and layout, making them with your own hands is elementary; the sensitivity of such devices makes it possible to work at depths of up to 200 mm.

High frequency finder

This assembly scheme is a little more complicated than the previous one. But also much more effective. Its difference is that there are two coils.

The first is the outer contour. A magnetic field is created directly in this coil. The second is the receiving circuit. This part is designed to receive, process, and amplify signals that come from the earth.

Making a deep metal detector with your own hands

First you need to assemble the so-called command block. Suitable for creating it old computer, the same old laptop or radio. Then you need to find the highest frequency in the AM band. You need to make sure that there is no radio station on the frequency.

Search head

To assemble the search head, you need to cut two circles from thin plywood. One of them should have a diameter of about 15 cm, the second should be made a little smaller. This is done so that the rings can be inserted into each other. Then we need to cut out small pieces of wood so that our head rings are parallel.

After this, 10-15 turns of enameled wire with a cross-section of 0.25 mm from the outer circle should be removed from the plates. You also need to secure the resulting structure. For everything to work, you need to connect the head from the bottom and the detector from the top.

It's time to turn on our frequency. A faint tonal sound will be heard. It's better to use headphones.

Metal detector "Pirate"

Assembling the device is not difficult at all. The device circuit does not contain programmable microcircuits; it is easy to make and configure this metal detector with your own hands. Detailed instructions will help with this. Also, this scheme does not contain expensive or scarce parts. "Pirate" in its parameters can surpass foreign, quite expensive industrial analogues.

Options

For power supply you will need from 9 to 12 V. The current consumed by the device is up to 40 mA. Sensitivity will be up to 150 cm subject to large metal objects.

How is the element base for a metal detector made?

The “Pirate” type circuit consists of two nodes. This is a transmitting circuit, which consists of a pulse generator based on KR1006VI1 and a switch made from an IRF740 transistor. The receiver is made on the basis of the K157UD2 microcircuit and the VS547 transistor.

The coil should have 190 mm in diameter. The number of turns on the PEV wire is 0.5 - 25. The transistor in the circuit can be pulled out of an ordinary energy-saving light bulb or any charger for mobile phones. A properly assembled “Pirate” metal detector with your own hands practically does not need to be configured.

"Terminator"

The device has good capabilities. For example, the device will detect a coin with a denomination of 5 Russian rubles from 25 cm. The finder will recognize a German military helmet from 80 cm. These values ​​are given on the condition of a coil with a diameter of 240 mm. "Terminator" can recognize metals even at the maximum working depth.

It is worth saying that beginners are unlikely to be able to assemble a “Terminator” metal detector with their own hands. The device requires careful setup. Even experienced craftsmen sometimes make mistakes when assembling this circuit. The main thing here is not to rush.

In order to assemble the Terminator, you will need a multimeter, as well as an oscilloscope and an LC meter. They are not available to every person. However, you can try to create a special software and hardware complex based on a regular home personal computer.

Description

The terminator is a single-tone device that operates from pulsed beats. The finder is great for finding coins. Also, if you make a little modification, you can look for gold on the beaches, while completely ignoring any other metals. "Terminator" is also suitable for searching for any other objects from any alloys.

In conclusion

So, we found out how to make a “Pirate” metal detector with our own hands, and also looked at “Terminator”. As you can see, by devoting a minimal amount of free time and effort to the assembly, you can get a rather interesting, and most importantly, workable tool with which you can find ancient objects, and possibly expensive coins.