I can say without a doubt that this is the simplest metal detector I have ever seen. It is based on just one TDA0161 chip. You won't need to program anything - just assemble it and that's it. Another great difference is that it does not make any sounds during operation, unlike a metal detector based on the NE555 chip, which initially beeps unpleasantly and you have to guess the metal found by its tone.
In this circuit, the buzzer starts beeping only when it detects metal. The TDA0161 chip is a specialized industrial version for induction sensors. And metal detectors for production are mainly built on it, giving a signal when metal approaches the induction sensor.
You can purchase such a microcircuit at -
It is not expensive and is quite accessible to everyone.
Here is a diagram of a simple metal detector
Metal detector characteristics
- Microcircuit power supply voltage: from 3.5 to 15V
- Generator frequency: 8-10 kHz
- Current consumption: 8-12 mA in alarm mode. In search state approximately 1 mA.
- Operating temperature: -55 to +100 degrees Celsius
An old cell phone battery works well for power supply.
Coil: 140-150 turns. The diameter of the coil is 5-6 cm. Can be converted to a coil of larger diameter.
The sensitivity will depend directly on the size of the search coil.
In the scheme I use both light and sound signaling. You can choose one if you want. Buzzer with internal generator.
Thanks to this simple design, you can make a pocket metal detector or a large metal detector, depending on what you need more.
After assembly, the metal detector works immediately and does not require any adjustments, except for setting the response threshold with a variable resistor. Well, this is standard procedure for a metal detector.
So, friends, collect the things you need and, as they say, they will come in handy around the house. For example, to search for electrical wiring in a wall, even nails in a log...
Nowadays, many people try not to buy metal detectors, but to assemble them with their own hands. As a rule, it is believed that something made by hand is much worse than branded items. Practice has shown that a high-quality product can compete with metal detectors made in production.
It goes without saying that such a device may look a little worse in terms of aesthetics, but in terms of technical data, it will be competitive.
General information on metal detectors
Before you start build your own metal detector, you need to find out the principles of its operation and what types such equipment can be divided into.
Design
Metal detectors are mainly divided into five types. They differ in search depth and type of metal. They have a variety of functions that simplify the work, but still, even with such differences, some similar features can be identified.
Principle of operation
The structure of a metal detector system may seem complicated only at first glance. In fact, the whole process is simply the attraction of metal products using a magnetized coil. While the coil begins to attract metal parts, magnetic waves pass through it, and after that a signal is heard.
It is worth noting that the coils operate at low or high frequencies. If the equipment operates at low frequencies, then metal products will mainly be found only at a depth of four meters. In addition, a metal detector that operates at low frequencies can only detect large samples, while small metal parts on the surface will go undetected. A metal detector that reacts at high frequencies, on the contrary, finds only small details on the surface, but cannot work at a depth of more than two meters and search for large objects.
Type varieties
Metal detectors can be divided into 5 types, taking into account the device that is responsible for transmitting and receiving the signal.
How to make a metal detector with your own hands?
Making your own homemade metal detector is not too difficult, even if you do not have certain skills in electrical engineering and the system itself. Today there are quite a large number of metal detectors that can be assembled at home. They differ in the circuits that have to be used to create the control unit, materials and complexity of assembly.
As a rule, the most complex metal detector is assembled according to a scheme where it is necessary to install two generators into the system structure at once. This is quite difficult for a beginner. There is also a simpler type of metal detector that can be easily made at home, using only available materials.
Frame
The assembly of a homemade metal detector must begin with the development of the housing. It should be a simple barbell that can be welded or connected with fasteners. In fact, there are no defined frames for the case. Here, each person can make a barbell for himself, but it is important to remember some factors.
First of all, the material that is selected for the manufacture of the case must be strong enough to withstand the weight of an adult for a long time. In addition, we must not forget about the size of such a bar, because if you choose the wrong length for your height, each time you search for metal objects you will have to stand in a bent state for several minutes.
Many people simplify the task of creating a body by using a simple crutch, which also has an armrest. A crutch can be easily selected to suit your height, and it is not too expensive.
Search coil
Making a homemade search coil is quite difficult, but it is possible. The first step is to start creating a device for winding the coil. First you need to take a simple board measuring 18 by 18, nails and cambric.
After this, you need to draw an even circle on the board and drive at least 16 nails along its diameter, so that they protrude slightly by about 2 cm. After this, cambrics are installed on the nails, which are tightly wrapped with copper wire. At the end of the work, the entire copper circle is firmly secured with threads, which need to be wound around the entire diameter and treated with epoxy resin.
You need to leave a 4 cm long lead, tighten the coil with electrical tape and shield it with foil. The copper wire needs to be tinned to a length of 1.25 cm and then re-wind it onto the reel. Then the action is repeated, or, more precisely, the coil is wrapped with electrical tape. You will also need to solder a contact pad to the coil terminal.
Control block
To create a control unit you will need:
All the necessary parts can be found in an old transistor type receiver. To assemble the control unit, you will need to find a suitable housing and install all the parts.
The circuit and coil are connected together using shielded wire. The cable screen is soldered to the coil terminal, insulation is installed, and the cable is fixed to the housing using electrical tape.
Conclusion
Making an entry-level metal detector is quite simple at home using available tools. All you need to do is follow the instructions and diagrams for assembling the equipment. The result is a model that can be used to search for small metal objects at a depth of up to 1 m.
A device that allows you to search for metal objects located in a neutral environment, such as soil, due to their conductivity is called a metal detector (metal detector). This device allows you to find metal objects in various environments, including in the human body.
Largely thanks to the development of microelectronics, metal detectors, which are produced by many enterprises around the world, are highly reliable and have small overall and weight characteristics.
Not so long ago, such devices could most often be seen among sappers, but now they are used by rescuers, treasure hunters, and utility workers when searching for pipes, cables, etc. Moreover, many “treasure hunters” use metal detectors, which they assemble with their own hands .
Design and principle of operation of the device
Metal detectors on the market operate on different principles. Many believe that they use the principle of pulse echo or radar. Their difference from locators lies in the fact that the transmitted and received signals operate constantly and simultaneously; in addition, they operate at the same frequencies.
Devices operating on the “receive-transmit” principle record the signal reflected (re-emitted) from a metal object. This signal appears due to the exposure of a metal object to an alternating magnetic field generated by the metal detector coils. That is, the design of devices of this type provides for the presence of two coils, the first is transmitting, the second is receiving.
Devices of this class have the following advantages:
- simplicity of design;
- Great potential for detecting metallic materials.
At the same time, metal detectors of this class have certain disadvantages:
- metal detectors can be sensitive to the composition of the soil in which they search for metal objects.
- technological difficulties in the production of the product.
In other words, devices of this type must be configured with your own hands before work.
Other devices are sometimes called beat metal detectors. This name comes from the distant past, more precisely from the times when superheterodyne receivers were widely used. Beating is a phenomenon that becomes noticeable when two signals with similar frequencies and equal amplitudes are summed. The beat consists of pulsating the amplitude of the summed signal.
The signal pulsation frequency is equal to the difference in the frequencies of the summed signals. By passing such a signal through a rectifier, it is also called a detector, and the so-called difference frequency is isolated.
This scheme has been used for a long time, but nowadays it is not used. They were replaced by synchronous detectors, but the term remained in use.
A beat metal detector works using the following principle - it registers the difference in frequencies from two generator coils. One frequency is stable, the second contains an inductor.
The device is configured with your own hands so that the generated frequencies match or at least are close. As soon as metal enters the action zone, the set parameters change and the frequency changes. The frequency difference can be recorded in a variety of ways, from headphones to digital methods.
Devices of this class are characterized by a simple sensor design and low sensitivity to the mineral composition of the soil.
But besides this, when operating them, it is necessary to take into account the fact that they have high energy consumption.
Typical design
The metal detector includes the following components:
- The coil is a box-type structure that houses the signal receiver and transmitter. Most often, the coil has an elliptical shape and polymers are used for its manufacture. A wire is connected to it connecting it to the control unit. This wire transmits the signal from the receiver to the control unit. The transmitter generates a signal when metal is detected, which is transmitted to the receiver. The coil is installed on the lower rod.
- The metal part on which the reel is fixed and its angle of inclination is adjusted is called the lower rod. Thanks to this solution, a more thorough examination of the surface occurs. There are models in which the lower part can adjust the height of the metal detector and provides a telescopic connection to the rod, which is called the middle one.
- The middle rod is the unit located between the lower and upper rods. Devices are attached to it that allow you to adjust the size of the device. On the market you can find models that consist of two rods.
- The top rod usually has a curved appearance. It resembles the letter S. This shape is considered optimal for attaching it to the hand. An armrest, a control unit and a handle are installed on it. The armrest and handle are made of polymer materials.
- The metal detector control unit is necessary to process the data received from the coil. After the signal is converted, it is sent to headphones or other display devices. In addition, the control unit is designed to regulate the operating mode of the device. The wire from the coil is connected using a quick release device.
All devices included in the metal detector are waterproof.
It is this relative simplicity of design that allows you to make metal detectors with your own hands.
Types of metal detectors
There is a wide range of metal detectors on the market, used in many areas. Below is a list that shows some of the varieties of these devices:
Most modern metal detectors can find metal objects at a depth of up to 2.5 m; special depth products can detect a product at a depth of up to 6 meters.
Operating frequency
The second parameter is the operating frequency. The thing is that low frequencies allow the metal detector to see to a fairly large depth, but they are not able to see small details. High frequencies allow you to notice small objects, but do not allow you to view the ground to great depths.
The simplest (budget) models operate at one frequency; models that fall into the middle price range use 2 or more frequencies. There are models that use 28 frequencies when searching.
Modern metal detectors are equipped with a function such as metal discrimination. It allows you to distinguish the type of material located at depth. In this case, when ferrous metal is detected, one sound will sound in the search engine’s headphones, and when non-ferrous metal is detected, another sound will sound.
Such devices are classified as pulse-balanced. They use frequencies from 8 to 15 kHz in their work. Batteries of 9 - 12 V are used as a source.
Devices of this class are capable of detecting a gold object at a depth of several tens of centimeters, and ferrous metal products at a depth of about 1 meter or more.
But, of course, these parameters depend on the device model.
How to assemble a homemade metal detector with your own hands
There are many models of devices on the market for detecting metal in the ground, walls, etc. Despite its external complexity, making a metal detector with your own hands is not that difficult and almost anyone can do it. As noted above, any metal detector consists of the following key components - a coil, a decoder and a power supply signaling device.
To assemble such a metal detector with your own hands, you need the following set of elements:
- controller;
- resonator;
- capacitors of various types, including film ones;
- resistors;
- sound emitter;
- Voltage regulator.
Do-it-yourself simple metal detector
The metal detector circuit is not complicated, and you can find it either on the vast world wide web or in specialized literature. Above is a list of radio elements that are useful for assembling a metal detector with your own hands at home. You can assemble a simple metal detector with your own hands using a soldering iron or other available method. The main thing is that the parts should not touch the body of the device. To ensure the operation of the assembled metal detector, power supplies of 9 - 12 volts are used.
To wind the coil, use a wire with a cross-sectional diameter within 0.3 mm; of course, this will depend on the chosen circuit. By the way, the wound coil must be protected from exposure to extraneous radiation. To do this, shield it with your own hands using ordinary food foil.
To flash the controller firmware, special programs are used, which can also be found on the Internet.
Metal detector without chips
If a novice “treasure hunter” has no desire to get involved with microcircuits, there are circuits without them.
There are simpler circuits based on the use of traditional transistors. Such a device can find metal at a depth of several tens of centimeters.
Deep metal detectors are used to search for metals at great depths. But it is worth noting that they are not cheap and therefore it is quite possible to assemble it yourself. But before you start making it, you need to understand how a typical circuit works.
The design of a deep metal detector is not the simplest and there are several options for its implementation. Before assembling it, you need to prepare the following set of parts and elements:
- capacitors of various types - film, ceramic, etc.;
- resistors of different values;
- semiconductors - transistors and diodes.
Nominal parameters and quantity depend on the selected circuit diagram of the device. To assemble the above elements, you will need a soldering iron, a set of tools (screwdriver, pliers, wire cutters, etc.), and material for making the board.
The process of assembling a deep metal detector looks something like this. First, a control unit is assembled, the basis of which is a printed circuit board. It is made from textolite. Then the assembly diagram is transferred directly to the surface of the finished board. After the drawing is transferred, the board must be etched. To do this, use a solution that includes hydrogen peroxide, salt, and electrolyte.
After the board is etched, it is necessary to make holes in it to install the circuit components. After tinning the board. The most important stage is coming. Do-it-yourself installation and soldering of parts onto a prepared board.
To wind the coil with your own hands, use PEV brand wire with a diameter of 0.5 mm. The number of turns and the diameter of the coil depend on the selected circuit of the deep metal detector.
A little about smartphones
There is an opinion that it is quite possible to make a metal detector from a smartphone. This is wrong! Yes, there are applications that install under Android OS.
But in fact, after installing such an application, he will actually be able to find metal objects, but only pre-magnetized ones. It will not be able to search for, much less discriminate against, metals.
As a child, did you want to have a device that could be used to find metal objects and even treasure? Most children want to have such a unit. Fortunately, it exists. This is a conventional metal detector that allows you to detect various metals under a layer of soil and in other places. The principle is that it finds a material that differs in its magnetic or electrical properties from its environment. It is noteworthy that you can find not only metal objects and not only in the ground.
The metal detector is used by geologists, security services, the military, criminologists and construction workers. This is a very useful thing in the household. Is it possible to make a metal detector with your own hands? Yes, and this article will help you with this.
How does a metal detector work and what does it consist of?
In order to make such a device at home with your own hands, you need to understand the principle of its operation. How is it able to detect metal and signal it? It's all about electromagnetic induction. Metal detectors have their own circuit, consisting of:
- Transmitter of electromagnetic wave oscillations.
- Receiver.
- A special signal transmitting coil.
- Coil that receives the signal.
- Display devices.
- Discriminator (useful signal selection circuit).
Some operating units can be combined schematically and structurally. For example, both the receiver and the transmitter can operate on the same coil. Part of the receiver will immediately emit a positive signal and so on.
Now let’s take a closer look at the operating principle of the metal detector. Thanks to the coil, an EMF (electromagnetic field) of a certain structure begins to be created in the medium. In the case when an object that conducts electricity is within the range of this field, Foucault or eddy currents appear in it. They create the object’s own EMF. Now the original structure of the coil begins to become distorted. And when an object located in the ground does not conduct electricity, but has ferromagnetic properties, then due to shielding, the structure of the coil is also distorted. In both the first and second cases, the metal detector picks up the electromagnetic field from the object and converts it into a signal (acoustic or optical). You hear a certain sound and can see the signal on the screen.
Note! In general, for a metal detector to work, it is not necessary that the body conduct current; the ground does not. It is important that the magnetic and electrical properties of bodies differ.
This is how a metal detector system works. The principle is simple and effective. Now, let's take a closer look at how to make a metal detector with your own hands. The first thing you need is to prepare all the tools and materials.
Metal detector components
So, if you want to make a device, then you cannot do without special devices. This is still an electronic device that needs to be assembled from various components. What will be required? The set is as follows:
You can see other components in the diagram below.
Additionally, you will need a plastic box to mount the electronic circuit. Also prepare a plastic pipe to create a rod with a coil attached to it. Now you can get to work.
Assembling a metal detector with your own hands: creating a printed circuit board
The most difficult stage of work is the electronics. Everything here is subtle and complex. Therefore, it is rational to start with creating a working printed circuit board. There are only a few options for different boards. It all depends on the radioelements used to create it. There are boards operating on the NE555 chip and on transistors. Below you can see what these boards look like.
We assemble a metal detector with our own hands: installing electronic elements on the board
Further work will also not be easy. All electronic elements of the metal detector will have to be soldered and installed as shown in the diagram. In the photo you can see the capacitors. They are film-like and have high thermal stability. Due to them, the operation of the metal detector will be much more stable. This indicator is very useful, especially during the autumn period of using the device. After all, it gets quite cool outside then.
All that remains is to do the soldering. We will not describe the process itself, since the soldering technology should be known to everyone. To clearly understand how to perform all the work on the electronic part of the metal detector, we suggest that you additionally familiarize yourself with this video:
Assembling a metal detector with your own hands: power supply
In order for the device to receive current, you need to provide a power source of 9-12 V. It is worth noting that the metal detector consumes electricity quite voraciously. This is not surprising, since the device is quite powerful. If you think that one “Krona” (battery) will be enough, then this is not so. He won't work for long. You will need two or even three batteries connected in parallel. Alternatively, use one powerful battery. It will be cheaper since it can take a long time to discharge and charge.
Assembling a metal detector with your own hands: coil
Since we are making a pulsed metal detector, careful and precise assembly of the coil is not required. The normal diameter of the coil will be 19-20 cm. To do this, you will have to wind 25 turns. Once you have made the coil, wrap the top well with insulating tape. To increase the depth of detection of objects by the coil, wind the diameter of the send about 26-27 cm. In this case, you need to reduce the number of turns to 21-23. In this case, a wire Ø 0.5 mm is used.
Once you have wound the coil, you will need to mount it on the hard body of the metal detector. It is important that there is no metal on the body. Think and look for any case that will fit in size. The housing will perform a protective function. The coil will be protected from impacts on the ground during searches.
To make a tap from the coil, solder two wires Ø 0.5-0.75 mm to it. It is recommended to use 2 wires twisted together.
Assembling a metal detector with your own hands: setting up the device
When assembling a metal detector according to the diagram, you do not need to configure it. It already has maximum sensitivity. To fine-tune the metal detector, adjust the variable resistor R13 by twisting it slightly. Do this until you hear occasional clicks. In the case when this is achieved at the extreme position of the resistor, change the rating of the R12 device. Such a variable resistor should configure the metal detector to operate optimally in the middle position.
There is a special oscilloscope with which you can measure the gate frequency of resistor T2. The pulse length should be 130-150 μs, and the optimal operating frequency should be 120-150 Hz.
To start the metal detector search process, you need to turn it on and wait about 20 seconds. Then it will stabilize. Now twist resistor R13 to adjust it. That's all, you can start your search using a simple metal detector.
Let's sum it up
Such detailed instructions will help you learn how to make a metal detector yourself. It is simple but fully capable of finding metal objects. More complex models of metal detectors require more effort and time.
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 of electronic devices is 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. To create it, an old computer, an equally old laptop or a radio will do. 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 circuit 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.