Anyone can assemble such a device, even those who are completely far from electronics, you just need to solder all the parts as in the diagram. The metal detector consists of two microcircuits. They do not require any firmware or programming.
Power supply is 12 volts, you can use AA batteries, but it’s better to use a 12V battery (small)
The coil is wound on a 190mm mandrel and contains 25 turns of PEV 0.5 wire
Characteristics:
- Current consumption 30-40 mA
- Reacts to all metals, no discrimination
- Sensitivity 25 mm coin - 20 cm
- Large metal objects - 150 cm
- All parts are inexpensive and easily accessible.
List of required parts:
1) Soldering iron
2) Textolite
3) Wires
4) Drill 1mm
Here is a list of required parts
Diagram of the metal detector itself
The circuit uses 2 microcircuits (NE555 and K157UD2). They are quite common. K157UD2 - can be picked out from old equipment, which I did with success
Be sure to take 100nF film capacitors, like these, take the voltage as low as possible
Print out the board sketch on plain paper
We cut a piece of textolite to its size.
We apply it tightly and press it with a sharp object in the places of future holes.
This is how it should turn out.
Next, take any drill or drilling machine and drill holes
After drilling, you need to draw tracks. You can do this through, or simply paint them with Nitro varnish with a simple brush. The tracks should look exactly the same as on the paper template. And we poison the board.
In the places marked in red, place jumpers:
Next, we simply solder all the components into place.
For K157UD2 it is better to install an adapter socket.
To wind the search coil you need a copper wire with a diameter of 0.5-0.7 mm
If there is none, you can use another one. I didn’t have enough varnished copper wire. I took an old network cable.
He took off the shell. There were enough wires there. Two cores were enough for me, and they were used to wind the coil.
According to the diagram, the coil has a diameter of 19 cm and contains 25 turns. I’ll immediately note that the coil needs to be made of such a diameter based on what you will be looking for. The larger the coil, the deeper the search, but a large coil does not see small details well. The small coil sees small details well, but the depth is not great. I immediately wound three coils of 23cm (25 turns), 15cm (17 turns) and 10cm (13-15 turns). If you need to dig up scrap metal, then use a large one; if you are looking for small things on the beach, then use a smaller reel, but you’ll figure it out for yourself.
We wind the coil on anything of a suitable diameter and wrap it tightly with electrical tape so that the turns are tightly next to each other.
The coil should be as level as possible. The speaker took the first one available.
Now we connect everything and test the circuit to see if it works.
After applying power, you need to wait 15-20 seconds until the circuit warms up. We place the coil away from any metal, it is best to hang it in the air. Then we begin to twist the 100K variable resistor until clicks appear. As soon as the clicks appear, turn it in the opposite direction; as soon as the clicks disappear, that’s enough. After this, we also adjust the 10K resistor.
Regarding the K157UD2 microcircuit. In addition to the one I picked out, I asked one more from a neighbor and bought two at the radio market. I inserted the purchased microcircuits, turned on the device, but it refused to work. I racked my brains for a long time until I simply installed another microcircuit (the one I removed). And everything started working right away. So this is why you need an adapter socket, so that you can select a live microcircuit and not have to worry about desoldering and soldering.
Purchased chips
There is no need to explain to anyone what a metal detector is. This device is expensive, and some models cost quite a lot.
However, you can make a metal detector with your own hands at home. Moreover, you can not only save thousands of rubles on its purchase, but also enrich yourself by finding a treasure. Let's talk about the device itself and try to figure out what's in it and how.
Step-by-step instructions for assembling a simple metal detector
In this detailed instruction, we will show how you can assemble a simple metal detector with your own hands from available materials. We will need: a regular plastic CD box, a portable AM or AM/FM radio, a calculator, VELCRO type contact tape (Velcro). So let's get started!
Step 1. Disassemble the CD box body. Carefully disassemble the plastic CD case body, removing the insert that holds the disc in place.
STEP 1. Removing the plastic insert from the sideboxStep 2. Cut 2 strips of Velcro. Measure out the area at the center back of your radio. Then cut 2 pieces of Velcro the same size.
STEP 2.1. Measure approximately in the middle the area on the back of the radio (highlighted in red) 
STEP 2.2. Cut out 2 Velcro strips of the appropriate size measured in step 2.1 Step 3. Secure the radio. Use the sticky side to attach one piece of Velcro to the back of the radio and another to one of the inside sides of the CD case. Then attach the radio to the body of the plastic CD case using Velcro to Velcro.
Step 4. Secure the calculator. Repeat steps 2 and 3 with the calculator, but apply the Velcro to the other side of the CD case. Then secure the calculator to this side of the box using the standard Velcro-to-Velcro method.
Step 5. Setting the radio band. Turn on the radio and make sure it is tuned to the AM band. Now tune it to the AM end of the band, but not to the radio station itself. Turn up the volume. You should only hear static.
Clue:
If there is a radio station that is at the very end of the AM band, then try to get as close to it as possible. In this case, you should only hear interference!
Step 6. Roll up the CD box. Turn on the calculator. Start folding the side of the calculator box toward the radio until you hear a loud beep. This beep tells us that the radio has picked up an electromagnetic wave from the calculator's circuitry.
STEP 6. Fold the sides of the CD box towards each other until a characteristic loud signal is heard Step 7 Bring the assembled device to a metal object. Open the flaps of the plastic box again until the sound we heard in step 6 is barely audible. Then start moving the box with your radio and calculator close to the metal object and you will hear a loud sound again. This indicates the correct operation of our simplest metal detector.
Instructions for assembling a sensitive metal detector based on a dual-circuit oscillator circuit
Operating principle:
In this project we will build a metal detector based on a double oscillator circuit. One oscillator is fixed and the other varies depending on the proximity of metal objects. The beat frequency between these two oscillator frequencies is in the audio range. When the detector passes over a metal object, you will hear a change in this beat frequency. Different types of metals will cause a positive or negative shift, raising or lowering the audio frequency.
We will need materials and electrical components:
| Copper Multilayer PCB Single Sided 114.3mm x 155.6mm | 1 PC. |
| Resistor 0.125 W | 1 PC. |
| Capacitor, 0.1μF | 5 pieces. |
| Capacitor, 0.01μF | 5 pieces. |
| Capacitor, electrolytic 220μF | 2 pcs. |
| PEL type winding wire (26 AWG or 0.4 mm in diameter) | 1 unit |
| Audio jack, 1/8′, mono, panel mount, optional | 1 PC. |
| Headphones, 1/8′ plug, mono or stereo | 1 PC. |
| Battery, 9 V | 1 PC. |
| Connector for binding 9V battery | 1 PC. |
| Potentiometer, 5 kOhm, audio taper, optional | 1 PC. |
| Switch, single pole | 1 PC. |
| Transistor, NPN, 2N3904 | 6 pcs. |
| Wire for connecting the sensor (22 AWG or cross-section - 0.3250 mm 2) | 1 unit |
| Wired speaker 4′ | 1 PC. |
| Speaker, small 8 ohm | 1 PC. |
| Locknut, brass, 1/2′ | 1 PC. |
| Threaded PVC pipe connector (1/2′ hole) | 1 PC. |
| 1/4′ wood dowel | 1 PC. |
| 3/4′ wooden dowel | 1 PC. |
| 1/2′ wooden dowel | 1 PC. |
| Epoxy resin | 1 PC. |
| 1/4′ plywood | 1 PC. |
| Wood glue | 1 PC. |
We will need tools:
So let's get started!
Step 1: Make a PCB. To do this, download the board design. Then print it out and etch it onto the copper board using the toner to board transfer method. With the toner transfer method, you print a mirror image of the board design using a regular laser printer, and then transfer the design onto the copper cladding using an iron. During the etching stage, the toner acts as a mask, preserving the copper traces while like the rest copper dissolves in chemical bath.
Step 2: Fills the board with transistors and electrolytic capacitors . Start by soldering 6 NPN transistors. Pay attention to the orientation of the collector, emitter and base legs of the transistors. The base leg (B) is almost always in the middle. Next we add two 220μF electrolytic capacitors.
Step 2.2. Add 2 electrolytic capacitors Step 3: Fill the board with polyester capacitors and resistors. Now you need to add 5 polyester capacitors with a capacity of 0.1μF in the places shown below. Next, add 5 capacitors with a capacity of 0.01μF. These capacitors are not polarized and can be soldered onto the board with legs in any direction. Next, add 6 10 kOhm resistors (brown, black, orange, gold).
Step 3.2. Add 5 capacitors with a capacity of 0.01μF 
Step 3.3. Add 6 10 kOhm resistors Step 4: We continue to fill the electrical board with elements. Now you need to add one 2.2 mOhm resistor (red, red, green, gold) and two 39 kOhm resistors (orange, white, orange, gold). And then solder in the last 1 kOhm resistor (brown, black, red, gold). Next, add pairs of wires for power (red/black), audio output (green/green), reference coil (black/black), and detector coil (yellow/yellow).
Step 4.1. Add 3 resistors (one 2 mOhm and two 39 kOhm) 
Step 4.2. Add 1 1 kOhm resistor (far right) 
Step 4.3. Adding wires Step 5: We wind the turns onto the reel. The next step is to wind turns on 2 coils, which are part of the LC generator circuit. The first is the reference coil. I used 0.4mm diameter wire for this. Cut a piece of dowel (about 13mm in diameter and 50mm in length).
Drill three holes in the dowel to allow the wires to pass through: one lengthwise through the middle of the dowel, and two perpendicularly at each end.
Slowly and carefully wrap as many turns of wire as you can around the dowel in one layer. Leave 3-4mm of bare wood at each end. Resist the temptation to "twist" the wire - this is the most intuitive way to wind, but this is the wrong way. You must rotate the dowel and pull the wire behind you. This way he will wrap the wire around himself.
Pull each end of the wire through the perpendicular holes in the dowel, and then one of them through the longitudinal hole. Secure the wire with tape once you're done. Finally, use sandpaper to remove the coating on the two open ends of the coil.
Step 6: We make a receiving (search) coil. It is necessary to cut the spool holder from 6-7 mm plywood. Using the same 0.4mm diameter wire, wind 10 turns around the slot. My reel has a diameter of 152 mm. Using a 6-7 mm wooden peg, attach the handle to the holder. Do not use a metal bolt (or anything similar) for this - otherwise the metal detector will constantly detect treasure for you. Again, using sandpaper, remove the coating on the ends of the wire.
Step 6.1. Cut out the spool holder 
Step 6.2 We wind 10 turns around the groove with a wire 0.4 mm in diameter 
Step 7: Setting up the reference coil. Now we need to adjust the frequency of the reference coil in our circuit to 100 kHz. For this I used an oscilloscope. You can also use a multimeter with a frequency meter for these purposes. Start by connecting the coil into the circuit. Next, turn on the power. Connect the probe from an oscilloscope or multimeter to both ends of the coil and measure its frequency. It should be less than 100 kHz. You can, if necessary, shorten the coil - this will reduce its inductance and increase the frequency. Then new and new dimensions. Once I got the frequency under 100kHz, my coil was 31mm long.
Metal detector on a transformer with W-shaped plates
The simplest metal detector circuit. We will need: a transformer with W-shaped plates, a 4.5 V battery, a resistor, a transistor, a capacitor, headphones. Leave only the W-shaped plates in the transformer. Wind 1000 turns of the first winding, and after the first 500 turns, make a tap with PEL-0.1 wire. Wind the second winding 200 turns with PEL-0.2 wire.
Attach the transformer to the end of the rod. Seal it against water. Turn it on and bring it close to the ground. Since the magnetic circuit is not closed, when approaching the metal, the parameters of our circuit will change, and the tone of the signal in the headphones will change.
A simple circuit based on common elements. You need transistors of the K315B or K3102 series, resistors, capacitors, headphones, and a battery. The values are shown in the diagram.
Video: How to properly make a metal detector with your own hands
The first transistor contains a master oscillator with a frequency of 100 Hz, and the second transistor contains a search oscillator with the same frequency. As a search coil, I took an old plastic bucket with a diameter of 250 mm, cut it off and wound a copper wire with a cross-section of 0.4 mm2 in the amount of 50 turns. I placed the assembled circuit in a small box, sealed it and secured everything to the rod with tape.
Circuit with two generators of the same frequency. There is no signal in standby mode. If a metal object appears in the field of the coil, the frequency of one of the generators changes and sound appears in the headphones. The device is quite versatile and has good sensitivity.
A simple circuit based on simple elements. You need a microcircuit, capacitors, resistors, headphones, and a power source. It is advisable to first assemble coil L2, as shown in the photo:
A master oscillator with coil L1 is assembled on one element of the microcircuit, and coil L2 is used in the search generator circuit. When metal objects enter the sensitivity zone, the frequency of the search circuit changes and the sound in the headphones changes. Using the handle of capacitor C6 you can tune out excess noise. A 9V battery is used as a battery.
In conclusion, I can say that anyone who is familiar with the basics of electrical engineering and has enough patience to complete the job can assemble the device.
Principle of operation
So, a metal detector is an electronic device that has a primary sensor and a secondary device. The role of the primary sensor is usually performed by a coil with a wound wire. The operation of the metal detector is based on the principle of changing the electromagnetic field of the sensor by any metal object.
The electromagnetic field created by the metal detector sensor causes eddy currents in such objects. These currents cause their own electromagnetic field, which changes the field created by our device. The secondary device of the metal detector registers these signals and notifies us that a metal object has been found.
The simplest metal detectors change the sound of the alarm when the desired object is detected. More modern and expensive samples are equipped with a microprocessor and a liquid crystal display. The most advanced companies equip their models with two sensors, which allows them to search more efficiently.
Metal detectors can be divided into several categories:
- public devices;
- mid-range devices;
- devices for professionals.
The first category includes the cheapest models with a minimal set of functions, but their price is very attractive. The most popular brands in Russia: IMPERIAL - 500A, FISHER 1212-X, CLASSIC I SL. Devices in this segment use a “receiver-transmitter” circuit operating at ultra-low frequencies and require constant movement of the search sensor.
The second category, these are more expensive units, have several replaceable sensors and several control knobs. They can work in different modes. The most common models: FISHER 1225-X, FISHER 1235-X, GOLDEN SABER II, CLASSIC III SL.
Photo: general view of a typical metal detector All other devices should be classified as professional. They are equipped with a microprocessor and can operate in dynamic and static modes. Allows you to determine the composition of the metal (object) and the depth of its occurrence. The settings can be automatic, or you can adjust them manually.
To assemble a homemade metal detector, you need to prepare several items in advance: a sensor (a coil with a wound wire), a holder rod, an electronic control unit. The sensitivity of our device depends on its quality and size. The holder bar is selected according to the person’s height so that it is convenient to work. All structural elements are fixed to it.
You can buy it for about 100-300 dollars. The price of metal detectors is strongly related to their detection depth; not every metal detector can “see” coins at a depth of 15 cm. In addition, the cost of a metal detector is also greatly affected by the presence of a metal type recognizer and the type of interface; fashionable metal detectors are sometimes equipped with a display for convenient operation .
This article will look at an example of assembling a powerful metal detector called Pirat with your own hands. The device is capable of catching coins underground at a depth of 20 cm. As for large objects, it is quite possible to work at a depth of 150 cm.
Video of working with a metal detector:
This metal detector received this name due to the fact that it is pulsed, this is the designation of its first two letters (PI-pulse). Well, RA-T is consonant with the word radioskot - this is the name of the developers’ site, where the homemade product was posted. According to the author, the Pirate is assembled very simply and quickly; even basic skills in working with electronics are enough for this.
The disadvantage of such a device is that it does not have a discriminator, that is, it cannot recognize non-ferrous metals. So it will not be possible to work with it in areas contaminated with various types of metals.
Materials and tools for assembly:
- microcircuit KR1006VI1 (or its foreign analogue NE555) - the transmitting node is built on it;
- transistor IRF740;
- K157UD2 microcircuit and BC547 transistor (the receiving unit is assembled on them);
- wire PEV 0.5 (for winding the coil);
- NPN type transistors;
- materials for creating the body and so on;
- electrical tape;
- soldering iron, wires, other tools.
The remaining radio components can be seen in the diagram.
You also need to find a suitable plastic box for mounting the electronic circuit. You will also need a plastic pipe to create a rod on which the coil is attached.
Metal detector assembly process:
Step one. Creating a printed circuit board
The most complex part of the device is, of course, the electronics, so it makes sense to start there. First of all, you need to make a printed circuit board. There are several board options, depending on the radio elements used. There is a board for NE555, and there is a board with transistors. All the necessary files to create the board are included in the article. You can also find other board options on the Internet.
Step two. Installing electronic elements on the board
Now the board needs to be soldered, all electronic elements are installed exactly as in the diagram. In the picture on the left you can see the capacitors. These capacitors are film capacitors and have high thermal stability. Thanks to this, the metal detector will work more stably. This is especially true if you use a metal detector in the fall, when it is sometimes quite cold outside.
Step three. Power supply for metal detector
To power the device, you need a source from 9 to 12 V. It is important to note that the device is quite voracious in terms of energy consumption, and this is logical, because it is also powerful. One Krona battery will not last long here; it is recommended to use 2-3 batteries at once, which are connected in parallel. You can also use one powerful battery (best rechargeable).
Step four. Assembling a coil for a metal detector
Due to the fact that this is a pulse metal detector, the accuracy of the coil assembly is not so important here. The optimal diameter of the mandrel is 1900-200 mm; a total of 25 turns need to be wound. After the coil is wound, it needs to be thoroughly wrapped on top with electrical tape for insulation. To increase the detection depth of the coil, you need to wind it on a mandrel with a diameter of about 260-270 mm, and reduce the number of turns to 21-22. In this case, a wire with a diameter of 0.5 mm is used.
After the coil is wound, it must be installed on a rigid body; there should be no metal on it. Here you need to think a little and look for any suitable housing. It is needed to protect the coil from shock while working with the device.
The leads from the coil are soldered to a stranded wire with a diameter of about 0.5-0.75 mm. It is best if there are two wires twisted together.
Step five. Setting up a metal detector
When assembling exactly according to the diagram, you do not need to adjust the metal detector; it already has maximum sensitivity. To fine-tune the metal detector, you need to twist the variable resistor R13, you need to achieve rare clicks in the speaker. If this can only be achieved in the extreme positions of the resistor, then it is necessary to change the value of resistor R12. The variable resistor should set the device to normal operation in the middle positions.
A metal detector is a device that can be used to find metal objects underground. There are many types and varieties of this device. The main differences are in scanning depth and ease of use. The deeper a metal detector “sees,” the more expensive its cost.
The principle of its operation is based on the magnetic attraction of objects. The device generates a magnetic field that you direct into the ground. As soon as an object is encountered, the field is reflected from it and returns back. In this case, a signal about the find is issued.
Now we will tell you how to make a metal detector with your own hands.
- Timer chip 555 (SE555/NE555);
- Resistor forty-seven kilo-ohms;
- Two 2.2 microfarad capacitors;
- Battery "Krona" nine volts;
- Buzzer;
- Copper wire 0.2 millimeters in diameter;
- Wires;
- Scotch;
- A piece of cardboard;
- Glue.
- Any discs, but double-sided ones are better, so the device will be more sensitive.
- Headphones.
- Calculator without solar panels.
- The battery is 9 volt, you can use the crown.
- Glue.
- Insulating tape.
Show all
How to make a high-frequency metal detector with your own hands?
First, assemble the command block. You can use a laptop or radio for this.
Tune the radio to the AM frequency, as high as possible. Make sure there is no radio station operating on this frequency.
Now you need to make a search head. To do this, cut out two circles using a thin plywood sheet as the material. One should have a diameter of fifteen centimeters, the other approximately ten, so that they can fit into each other.
Now cut out the sticks from wood so that the rings are parallel to each other.
Using enameled copper wire a quarter of a millimeter thick, make fifteen turns from the plates.
Now you can attach the craft to the block itself.
Take a pole and attach a head to the lower end, and a radio detector to the upper end.
Turn on the frequency. If you did everything correctly, a quiet sound will be heard. To hear it better, you can connect headphones.
How to make a metal detector with your own hands? Easy way
You will need:
Electrical diagram
Making a coil
To make a coil with your own hands with a diameter of ninety millimeters, you need to wind two hundred and fifty turns of copper wire, and for a coil with a diameter of seventy millimeters - two hundred and ninety turns. After these manipulations we get 10 mH.
The frames for the coils can be made of cardboard and the wire is wound on them.
Testing the circuit
Assemble the parts on the circuit board and check how it works.
If everything works as it should, you make a printed circuit board on which you assemble all the parts.
Making a handle for the device
You can make it yourself using cardboard for the base. From it you cut out three identical parts in the shape of a boomerang, and make a hole in them for the battery. Then glue all three parts together. Dry and cut out a place for the switch. Attach the circuit, connect the battery, switch and glue the coil.
Checking the resulting metal detector
What you will need:
Cut off the headphone plug and strip off the insulation at the ends. Expose the wires by ten millimeters.
Divide the stripped wires into two parts, you get four wires.
Take one end of the wire from different headphones and glue it to the writing sides of both discs.
Using electrical tape, secure the wires to the drives.
Connect the two bare ends of the wires that remain to the plus and minus of the battery and also secure with electrical tape.
Turn on the calculator and attach it to the top of one of the disks.
Place the second disk on the calculator and fasten the disks with electrical tape.
Again, use electrical tape to attach the battery to the disk.
Ready! You can test it.
Metal detector at home
To get started, stock up on an empty computer disk box.
Take a small radio and attach it with the back wall to one of the doors of the box.
You also attach a working calculator without solar panels to the other door with its back.
Now set up the device. Turn on the radio and switch it to the AM reception range. Make sure there is no broadcast on this frequency. If it is on, adjust the dial until there is complete silence on the air. When you turn the receiver volume up to maximum, you should only hear noise.
The time has come to check the functionality of the device. To do this, slowly and slowly close the box. At some point there will be a loud sound. This means that the radio picked up the magnetic waves emitted by the calculator.
Now open the box so that the sound is not loud. Hold the box in this position, bring it to a metal object, and you will hear the same loud sound. This means that the device is working.
This is such a simple device that it is better to use it to find lost metal products at home. It is possible in nature, but there you need a more advanced device.
Simple and reliable metal detector
Electrical diagram
In order to make such a device, you will first need a vinyl plastic tube, the outer diameter of which is one and a half centimeters, and the inner diameter is one centimeter. It needs to be twisted into a ring twenty-five centimeters in diameter. This will serve as the base of the search coil (indicated in the diagram as L1). Do not forget to provide an exit hole; a stick will be inserted into it for holding.
Wrap the coil a hundred times with PELSHO wire with a diameter of 02.7, wrap aluminum foil in the form of a tape along the top, it will serve as a screen for the device. It is important that you remember to leave a small gap in the screen so that the L1 coil does not become shorted.
The device is powered by a battery or battery. You can control the frequency and sound of the signal using headphones.
Today, there are many different ideas on the Internet that allow you to make a metal detector with your own hands at home. Some of them require certain skills in working with electrical appliances, soldering and understanding of simple electrical circuits, while some do not require any knowledge in these areas to create. However, there are many non-working, fake methods floating around the Internet, captivating with their simplicity and accessibility. It is very easy for an inexperienced person to fall for the bait of deceivers - to spend time and effort on making a device that is obviously not working and lose all interest in it. But don’t be discouraged, then readers of “” will be provided with an interesting and really working scheme for creating a homemade metal detector!
Idea No. 1 – Discs in action!
Surely you have already seen or heard that you can make the simplest metal detector yourself using a CD and DVD disc, as shown in the photo. The scheme is quite simple and does not require any professional tools or skills.
This instruction is the most popular due to the availability of the necessary components and the simplicity of its assembly; all you need to do is connect a couple of wires and the crown together and the device is ready. At the same time, the characteristics of this device are attributed to be quite good - it finds a coin at a distance of 25-30 cm, which is quite enough for searching for coins and treasures. However, unfortunately, this instruction is fake.
The fact is that the metal detector itself is a rather complex device; its operation is based on several physical phenomena at once. Therefore, a calculator and a pair of disks cannot even remotely replicate its operating principle, no matter what the creators of such instructions claim, who sometimes write that they even find treasures with the help of such homemade products.
It is very easy to understand that you are being deceived even without knowledge of the laws of physics. The wires from the headphones that need to be attached to the disk do not actually contact it in any way, since the copper is under a layer of varnish insulation, which must be removed by firing and labor-intensive cleaning of carbon deposits; of course, none of the authors of the instructions does this in their devices . Consequently, the headphones are simply not connected to any circuit, and there can be no talk of any work, much less metal detecting.
A real metal detector operates on the basis of an induction balance; its design must have at least one coil of copper wire. When a metal object enters the field of the coil, its characteristics or the received signal, depending on the design, change. These changes are recorded and amplified by the circuit, and also displayed in a form understandable to humans, usually by means of sound signals.
Video instructions for assembling a metal detector from disks
Idea No. 2 – Metal detector according to the “Pirate” scheme
This is a scheme that has been tested by many DIYers and allows you to achieve good results. It contains two microcircuits, so you will have to make a small printed circuit board or assemble the device on a breadboard. But don’t be alarmed, anyone can make this option if they put in the necessary effort. Below is an electronic circuit diagram of the device and a printed circuit board for it.
The coil is made of enameled copper wire with a diameter of 0.5 mm. Winding should be done on a frame with a diameter of 200-260 mm, the number of turns from 21 to 25. For reliability, it is better to install the coil in a protective plastic casing, which can then be attached to a handle made of PVC pipes.
After assembling the metal detector, it must be checked. The procedure for use is as follows: turn on the device away from metal objects for about 30 seconds so that its operation is more stable, then rotate the variable resistor knob for coarse and fine adjustment, you need to achieve rare clicks. When metal enters the action area, you will hear a characteristic sound.
Below is a detailed video assembly instruction, which clearly shows all the stages of creating a homemade metal detector.