How to make a metal detector with his hands

Now, perhaps, there is no man who does not know that such a metal or a metal detector. But let us recall once again, this is a device that allows to determine the location of a hidden metal. Metal is very popular with amateur archaeologists and treasure hunters. The device is quite expensive and some models and does have sky-high price, which is why most radio fans prefer to collect it yourself. In today's article we will look at how to make the detector with their hands, the device operating principle, popular scheme, as well as features of the assembly and setup.

How does a metal detector

The detector or detector - an electronic device consisting of a primary sensor (coil winding) and the secondary node. Devices for the detection of metals separated into several types:

1. "Handover";
2. induction;
3. Switching;
4. generator.

mid-priced devices are mainly related to the type of "Handover". The operating principle of these metal detectors based on the transmission and reception of electromagnetic waves. The main elements of the apparatus of this type are the two coils: one - transmitting, and the second - the host. The first coil transmits electromagnetic waves freely passing through a neutral medium and which, when a collision with metal objects are recorded and transmitted to the receiving device. After the reflected signal reaches the second coil, buzzer operator is informed of the finding purpose.

Induction type metal detector works on the same principle as the "Handover" device. The main difference between them is the number of coils with a winding. In one induction metal coil which sends and receives a signal simultaneously. Switching devices are insensitive to salt concentrations in the soil and include in their design coil, an electromagnetic field which induces an eddy current on the metal surface which are removed detector. This principle of action reduces the possibility of discrimination that may complicate the search.

Metal generating type are of different types, but all of them are based on the LC-oscillator. They have a low level of sensitivity and, as a rule, intended to find only one type of metal. Also, metal detectors can be divided into three categories:

1. common use;
2. middle class;
3. professional equipment.

Functional and technical specifications of metal detectors

Before you choose and buy a good metal detector should be clearly defined with the environment in which will be carried out exploration work. It is also necessary to take into account the estimated size of the desired objects and their depth. Consider the main characteristics that you need to pay special attention to when buying a detector:

• operating principle;
• the operating frequency of the device;
• sensitivity;
• the weight;
• balancing the soil;
• target designation;
• discriminator;
• additional functions.

Principle and operation frequency detector - basic characteristics determining device capabilities and showing what category it is possible to carry (compactor simple, middle class or professional). Sensitivity determines the depth of bedding items, which can operate the device. Typically, this component is in the range of 100-150 mm and 600-1500 mm. However, there are deep-seated models, designed to search for objects at a depth of 5 meters. Discriminator makes it possible to configure the device to search for a specific kind of metal. This allows the operator to not be distracted by the metalized debris.

What types of metal detectors can be made with your own hands

You can purchase a detector in a specialty store or make metal with their hands at home. There are schemes that are possible even for novice hobbyists. For devices that can be collected on their own, could be considered:

• "Butterfly";
• device without chips (IC);
• model "Pirate";
• "Terminator 3" and so forth.

On the Internet runs the information that can be alleged to collect their own hands metal from the phone. Remember two words - it is a fiction. There are some applications which can be enabled tablet or smartphone in the detector circuit, but a full-fledged device for the search of metals and their recognition is impossible.

How to assemble their own hands metal "Pirate": detailed instructions

"Pirate" series models cost about $ 100-300. This value derives from the ability of the device to detect objects in a depth of 200 mm (for small items) and 1,500 mm (large cells). Consider the features of the assembly and device settings to search for metals, as well as its components.

The materials needed to build their own hands a powerful metal detector

The following materials and components needed for the manufacture of metal detector:

• IC KR 1006VI1 or NE 555 (foreign equivalent) to create the transmitting unit;
• IRF 740 transistor;
• K IC 157UD2 transistor and sun 547 to the receiving node assembly;
• type transistors NPN;
• wire PEV 0.5 to create coils;
• materials for housing, rods, etc .;
• plate coated with the copper sheet, for the manufacture of printed circuit board;
• wire;
• insulating tape;
• side cutters;
• soldering;
• scalpel;
• Screwdriver Set;
• pliers;
• different types of fasteners.

Collect metal detector with your hands: the scheme

At present, the detector "Pirate" circuit a lot, because some hams began to upgrade them to suit your needs. All options will be considered, only the most proven and most popular.

The detector circuit on a chip NE555

The classical scheme of the detector series "Pirate", built on the IMS-timer NE555. Operation depends on the comparator, one output of which is attached to a generator IC pulses to the second coil, and output to the speaker. In the case of metal detection signal from the coil is supplied to the comparator, and after the speaker, which alerts the operator to the presence of the desired items.

Build your own hands without the detector chip

In contrast to the previous scheme, this device for generating signals used Soviet type transistors CT-361 and CT-315 (you can use the same radio components).

The printed circuit board with your hands

Details bought scheme there, and now you need to collect all of this. Electronic components used to accommodate printed circuit board, which is easy to make yourself. You will need a piece of sheet Micarta coated electrical copper foil. At selected workpiece transfer circuit, to designate a track, connecting parts, and to drill holes in the places of attachment and soldering. Lanes covered with a protective varnish, and after drying omit future fee in ferric chloride for etching (removing the unprotected portions of the copper foil).

Once the board is ready, you can install and unsoldering radio. The next step is to check the circuit by means of measuring instruments.

Reel detector - how to make your own hands

Due to the fact that the metal detector, "Pirate" is a pulse type device, the accuracy in the assembly of the coil is unimportant. For the base ring with the required order of 200 mm diameter, on which need to wind the wire coils 25 PEV 0.5 mm. To increase the depth of metal detection coil bobbin must be within 260-270 mm and the number of turns - 21-22 vol. Next, the mandrel with the wire should be well covered with insulating tape.

The finished coil placed in the body of a dielectric material. You can use the appropriate sized body of a faulty home appliances "junk." By the way, it will help protect the coil from damage during operation with the detector. Conclusions windings are soldered to the multi-core wire with a diameter in the range 0.5-0.7 mm. It is best to use a twisted-pair cable.

Checking and adjusting the metal detector

At rod detector fasten all device nodes: a body with coil receiving-transmitting unit and a handle. If the control circuit is assembled correctly, the device setting is not required, as it initially has a maximum sensitivity. More fine-tuning is performed by the variable resistor R13. Normal operation of the detector should be provided with an average position of the regulator. If there is an oscilloscope, then using it to the gate of transistor T2 is necessary to measure the frequency that should be 120-150 Hz, and pulse width - 130-150 microseconds.

The video shows how to configure the detector.

How to make an underwater metal detector with their hands

Sometimes the search operations have to move from the land into the water. How to be in such a case, because the electronics will be damaged? There are, of course, a special device to work under the water, but you can make a deep metal with their hands. To do this, you can take the most common homemade detector and put all the nodes in a hermetically sealed housing. Also worth slightly modify the device and instead set the alarm sound lights.

How to make your own hands metal "Terminator 3": a detailed instruction

Model "Terminator 3" has long been popular among amateur radio operators, and for many years the existence of the unit has received a lot of improvements. We offer step by step instructions on how to make a metal detector at home. The device is characterized by low power consumption, it is possible to configure to search for specific types of metal and good depth characteristics.

Instruments

Before you make a homemade metal detector, you need to prepare the following tools:

• soldering or soldering station;
• solder, tin, rosin;
• pliers, pliers, side cutters;
• Screwdriver Set;
• hacksaw;
• oscilloscopes and other instrumentation.

Scheme, selection of parts and circuit board

For the manufacture of the control unit is necessary to make a circuit board, which will be located all the necessary radio components. Chart below, must be transferred to getinaksovoy plate having a copper foil covering the circuit board and manufactured in the same manner as described above for the detector in the article "Pirate". circuit size must be within 104 × 66 mm and the blank card 10 mm longer on each side.

How to prepare a printed circuit board for the detector to describe in detail the steps below:

Illustration	Process description
	Take textolite plate with the copper foil surface. Degreased chemically or mechanically (sanding).
	Draw diagram of a plate cover tracks protective varnish and subjecting the workpiece etching (described above for the detector "Pirate"). A thin drill to drill holes for fasteners and electronic components to the body.
	We place the radio in accordance with the scheme and conduct pinout.
	This is how will look ready to board the metal detector, "Terminator 3".

The coil metal detector

It is, in fact, the most sensitive part of the device. She is responsible for scanning the space under the ground. Consider the steps involved in creating a simple coil to the detector:

Illustration	Process description
	On delineates two circles plywood piece corresponding to the diameter of the coils - internal and external. Trying to drive nails around the perimeter of the circle. The diameter of the outer coil TX should be within 200 mm. The coil is made of two stacked wires. Drum nails 30 turns.
	Bandages winding thread on the circumference. Pull out nails, the resulting coil is varnished, and after it is dry, wrapped with electrical tape and foil. In the same way we produce inner winding RX, which is half the TX and comprises 48 turns of wire.
	Put the reels in a housing and carry out wiring of wires that will be connected to the control unit.
	Here it will look like the finished metal detector.

Homemade detector: texte assembly and tuning circuit

Detailed stages of assembly boards and the basic elements of the detector we discussed earlier, now we have the latest and responsible steps: assembling the housing and device configuration.

Illustration	Process description
	Take appropriate box or produce their own body. Drilled holes for the trimmer and the connector. Mount willing to pay and regulators in the case.
	Close the enclosure, connect a metal detector and fasten everything in a plastic tube with a handle. Metal assembled and ready to work.

The proposed video can help with the setting of the metal detector.

Features harvested their own hands metal detector with metal discrimination circuit

Metal detectors with a simple scheme allows to detect hidden objects, but to find out what it is, will have to work with a shovel. Instead of gold coins and military helmets, can be found only a piece of pipe, and spend a lot of time. To make it easier to search engines, the detectors were equipped discriminators that allow to distinguish between the type of metal and transmit various types of garbage. The simplest methods of determining the types of metals have been realized in older instruments and devices of the initial level and have two modes - "all metals" and "colored". Discrimination function allows the operator to respond to the phase shift of a certain value, the compared with the adjusted (reference) level. Thus the device can not distinguish between a non-ferrous metal.

In professional metal detectors are used to select a range of discriminators. Instruments used in such systems can be programmed microprocessor device to respond only to specific groups of metals. Discrimination useful on trash areas, but reduces the depth of detection of 10-20%.

Main features of the deep metal detector

Deep-type metal detector - a special device that can detect objects hidden in the large distance from the surface of the earth. It is at a considerable depth, you can find the most interesting and valuable items. Some models are methods of detecting metals in the region of 4 to 6 m below the ground.

Separate the two types of deep metal detectors: the frame and the transceiver on the bar. The first type of device is able to cover a large scanning area of ​​land. So, the search is accelerating, but a negative impact on performance. The second variant of the detector works in a small area, but it is better to determine the center of the target. With such a device a good search on the grass, wood or reeds. Therefore, when choosing the type of metal detector you need to determine the conditions under which the scan will be performed.

If you have a metal detector assembly experience with their hands, tell others about it! If you have questions for the author, ask it in the comments.