Devices for detecting voids, underground passages, burials, polyethylene gas pipelines and non-magnetic ammunition. Devices for searching for voids and inhomogeneities Devices for searching for voids

1) Project name:

Devices for detecting voids, underground passages, burials,polyethylene gas pipelinesand non-magnetic ammunition.

2) Brief description of the project:

The relevance of this topic lies in the fact that currently there are no portable and reliable instruments that allow us to determine the location of soil anomalies using existing methods, and by the nature of the anomalies detect voids, underground passages and burials. Search and discovery of biological remains is currently an unsolved global problem. Currently Domestic and imported radio wave mine detectors can only detect non-metallic objects, i.e. there is no selection of non-magnetic mines from stones and objects of similar size. Also available an urgent need for the army and intelligence services to detect a thin, unpowered cable during mine clearance(from a land mine to a radio fuse), such devices are currently absent in our country and abroad.

In the period 1990...2010, a number of modifications of IGA-1 devices were developed and tested to measure ultra-weak electromagnetic fields of the Earth’s natural field and the distortions of these fields introduced from absorption and re-emission by various objects. The devices are selective receivers of electromagnetic fields in the range of 5...10 kHz, with calculation of the integral of the phase shift at the measured frequency (http:// www. *****). The principle of operation of the IGA-1 device is similar to radio wave mine detectors, only there is no emitter, which is the natural background of the Earth and a lower frequency range. IGA-1 detects distortion of the electromagnetic field in places of soil heterogeneity in the presence of any objects underground, and is designed to search for non-metallic objects, voids, water veins, pipelines, human remains by changing the phase shift at the boundary of the transition of media. The output parameter of the device is the phase shift integral at the receiving frequency, the value of which changes at the boundary of the media transition (soil-pipe, soil-void). The device is made in the form of a portable measuring sensor with visual indication. The device is powered by a battery. The weight of all equipment in the suitcase does not exceed 5 kg, the weight of the measuring sensor does not exceed 1 kg.

3) Nature of the project:

Expansion of existing production

Carrying out R&D

Sale of licenses for the production of new versions of devices to other manufacturers.

4) Industry of application:

· High technology, high technology

6) Amount of required investment, in rubles

100 million rubles

7) Payback period, years

8) Project implementation period, years

9) Form of cooperation:

Share capital

· Share

10) Project readiness level

Since 1994, the Light-2 company has organized the production of IGA-1 devices on the basis of defense enterprises, producing more than 300 devices that are used in Russia and abroad. Options for IGA-1 devices for detecting water veins have been developed and do not require additional investment. Detection polyethylene gas pipelines worked out in manual (not automated) mode and requires the work of a well-trained operator.

Modernization and further development of IGA-1 devices is required for detecting voids, underground passages, burials and non-magnetic ammunition,polyethylene gas pipelinesaccording to received patents for inventions:

RF Patent N 2119680 dated 01/01/2001. Method of geoelectromagnetic exploration and device for its implementation. , and etc.

RF Patent No. 000 dated January 1, 2001. A method for detecting the location of buried biological objects or their remains and a device for its implementation. , and etc.

RF Patent No. 000 dated 01/01/01 “Device for searching and identifying plastic mines”, etc.

RF Patent No. 000 dated 01/01/01 “Device for searching underground pipelines”, etc.

For the search for human remains, the IGA-1 device was first tested in the village of Neftegorsk (1995); after the earthquake, about 30 dead were found. Feedback from the head of the administration of the village of Neftegorsk on the website http://www. *****. In Yekaterinburg (1996), the Ministry of Internal Affairs carried out work to discover corpses walled up in the Siberian Tract highway and burials in the forest in the area of ​​the Nizhneisetsky cemetery. Certificates from criminal case No. 000. Ekaterinburg, 1996 on the website http:// www. *****.

In using the IGA-1 device, it was possible to detect graves 100-150 years ago during the restoration and restoration of churches: St. George Monastery “Holy Bushes” in the Blagoveshchensky district of Bashkiria, the Church of the “Holy Trinity” in the village of Krasny Yar in Bashkortostan ( http:// www. *****), as well as other churches in Bashkortostan and Tatarstan.

In 2008, at the request of a resident of the city of Tuymazy, a search was made for the abandoned grave of his father Ivan Bezymyannikov, a war veteran and former secretary of the district committee. The grave was located in a city park; after the reconstruction of the park in 1991, traces of the burial were lost. After the excavations, the remains were reburied in the city cemetery. Photos on the website http://www. *****.
When conducting search studies (2003) in the area of ​​​​battles of the 1st separate mountain rifle brigade during the Great Patriotic War, in the Kirov district of the Leningrad region, using the IGA-1 device, the possibility of detecting filled-in trenches, dugouts and burials, as well as ammunition. It was found that the IGA-1 device reacts to ammunition and metal objects in a similar way to the IPM mine detector. To detect voids and burials, it is first necessary to detect and remove all metal from the area being examined, then the voids and burials are detected. For selective selectivity (only voids or human remains), it is necessary to further modernize and improve the IGA-1 device

Regarding the use of IGA-1 devices for engineering and sapper purposes, there was correspondence with the Security Council of the Russian Federation and the Ministry of Defense - direction on detecting non-magnetic mines. This invention was considered by the Commission on Scientific and Technical Issues of the Security Council of the Russian Federation (1995), in the Invention Department of the Ministry of Defense (), military unit 52684-A (Ex.565/2139 dated December 3, 1996), Central Research Institute 15 MO (ref. 1131 dated September 1, 1998). In the summer of 2000, an experimental model of the IGA-1 device in the mine detector version was tested at the Central Research Institute 15 MO for the possibility of detecting anti-tank, anti-personnel non-magnetic mines and unexploded land mines located at great depths, positive feedback was received ( http:// www. *****),. Disadvantages were also noted; to eliminate them, further development of the equipment is required, which requires additional investment. Considering that the world's mine detectors for non-magnetic mines do not distinguish them from stones of a similar size, further development of our method will make it possible to carry out such selection according to the frequency of reception by taking the spectral characteristics of detected objects. To determine the possibility of fixing unpowered cables during mine clearance (from a land mine to a radio fuse), one of the IGA-1 devices was configured for this task and tested on the bank of the river. Belaya in Ufa, in a place where there are no longer any communications, as a result, confirmation was received about the possibility of using IGA-1 for these tasks.

For the detection of underground passages in which terrorists may be hiding, the IGA-1 device was of great interest to Western military specialists at the exhibition of Russian developments and equipment for land mine clearance and ammunition disposal, which was held on April 29-30, 2002 in Moscow on enterprise "Basalt". Several IGA-1 devices were sold to organizations and treasure hunters for these tasks and are successfully used.

· Research and development

· Purchase of equipment

· Introduction of new technologies

12) There is support from authorities

There is no financial support at the moment

13) availability of a prepared business plan

Under development

14) Financial support for the project:

· There are currently no own funds.

· There is no government funding.

· Previously raised own funds since 1994 10 million rubles. in modern terms

· Missing funds 100 million rubles. for 5 years.

15) Granting rights to the investor:

· Acquisition of shares 48%

· Shares of the volume of profit received from the sale of licenses for the production of new proven versions of devices 50%

16) Contact information:

Contact address: Ufa, st. K. Marksa 65\1 apt 74

Contact person email: *****@***ru

The contact person:

Contact phone numbers: 0-69

17) Project Owner (select only one option depending on the project owner)

The OMP-1 device, described below, is designed to facilitate the solution of these problems. During testing, the device detected polygonometry points under the soil layer at a distance of 0.3-0.4 m, and well covers at a distance of 0.8-1 m.

The operating principle of the OMP-1 device is based on the fact that the frequency of the generator changes if the search coil approaches a metal object. The closer the search coil is to a metal object, the more the frequency of the generator increases. Therefore, by somehow registering a change in the frequency of the generator, it is possible to find a metal object. In this case, the maximum change in frequency corresponds to the minimum distance between the search coil and the metal object. Changes in the frequency of the generator can be recorded auditorily (using the beat method) or visually.

If a suitably configured FSS (focused selection filter) is connected between a generator with an external search coil and a DC amplifier, then when the frequency of the generator changes, the amplitude and, consequently, the collector current of transistor T3 will change. A 200 µA device is included in the T3 collector circuit.

The schematic diagram of the OMP-1 device is shown in Fig. 1. The sinusoidal oscillation generator is made on transistor T1 according to a three-point circuit. The operating point is determined by the voltage divider R1, R2 and resistance R3. In addition to the relatively high stability of frequency, amplitude and good vibration shape, the generator has another advantage: it uses a non-sectional search coil. Variable capacitor C5 allows you to change the generator frequency from 430 kHz to 500 kHz.

Fig.1. Schematic diagram of a device for detecting metal objects.

By changing the capacitance C5, you can choose the optimal location of the operating point on the frequency response of the FSS (in the area of ​​greatest steepness), this corresponds to the maximum sensitivity of the device. The sinusoidal voltage of the generator through resistance R4 is supplied to the FSS, tuned to a frequency of 445 kHz. Since the IF amplifiers in radio receivers are tuned to 465 kHz, the operating device does not create interference. The device uses the FSS used in the Atmosfera-2M radio receiver. With the help of adjusted cores, its circuits are adjusted to the operating frequency of the device (445 kHz) without changing the winding data of the coils. The device can also use FSS from other radio receivers. It is preferable to use high-quality loop coils, for example the FSS of the Topaz-2 and Sokol pocket radios.

The diagram shown in Fig. 2 differs from the first circuit (Fig. 1) by an additional second stage, which makes it possible to obtain a higher sensitivity of the device.

Fig.2. Schematic diagram of a device for detecting metal objects with an additional cascade

Setting up the device.

A correctly assembled generator begins to generate immediately, and its setup consists only in selecting a capacitance of capacitor C4 such that the generation frequency is approximately equal to 445 kHz. In this case, the rotor of the variable capacitor C5 must be set to the middle position. The frequency was measured by a ChZ-7 device, which was connected through a resistance of several kilo-ohms to the emitter terminal of transistor T1 and to the common positive terminal. To configure the FSS, you need a GSS-6 and an output meter (a device with a sensitivity of 200 μA).

The search coil, which is an oscillating circuit, must be placed in an electrostatic screen. It is made from a duralumin tube with a diameter of 12 mm in the form of a ring with a diameter of 390 mm. A slot is cut along the outer circumference of the ring with a hacksaw and 14 turns of PELSHO 0.28 wire are laid.

Fig.3. The main dimensions of the device for searching for metal objects.

Fig.4. installation of a device for searching metal products on a getinaks board.

After laying, the wire is impregnated with paraffin and the entire ring is wrapped with insulating tape or varnished cloth. The search coil is connected to the generator by a shielded coaxial cable that runs inside the tube. Both the ring itself and the tube are connected to the positive terminal of the power source (two KBS-0.5 batteries). They are located in the same housing with a microammeter. The tuning knob (variable capacitor C5) is brought out through holes in the bottom and cover of the body of the device itself. Variable resistance R14, connected in series with the microammeter, serves to adjust the sensitivity. When carrying the device, the ring is pressed against the tube and secured with a spring latch. The main dimensions of the device are shown in Fig. 3. Installation is carried out on a getinax board (Fig. 4) with dimensions 100x75x2 mm.

A. Zotov, V. Kharin

Electrical interference causes unstable operation of televisions, radios, electrocardiographs and other devices. Identifying the source of electrical noise takes a lot of time.

To quickly detect sources of industrial electrical interference, you can use a portable radio-acoustic device.

The operating principle of the device is based on recording the radio frequency spectrum of a spark discharge during a “far” (up to 200 m) search and a “close” (up to 7 m) search - the acoustic frequency spectrum of a spark discharge. In this case, the directional pattern of the acoustic sensor is 10-12 degrees. The location of the spark discharge is determined with an accuracy of ± 5 cm. The device can be used to find the locations of “quiet” coronary discharges, as well as to determine the locations of electrical discharges.

The device diagram is shown in Fig. 75, a.

I - radio sensor, consisting of a magnetic antenna tuned to a frequency of 40 kHz; 2 - acoustic sensor, consisting of a piezoelectric microphone with a horn; 3 - bandpass amplifier of ultrasonic frequencies with a bandwidth of 4 kHz and an average frequency of 40 kHz; 4 - amplitude detector; 5—low-pass filter; 5 - low frequency amplifier; 7 — headphones; 8— amplifier to the dial indicator; 9 - pointer indicator.

The device works as follows. Electromagnetic oscillations from the spark discharge are induced in the magnetic antenna. d.s. with a wide range of frequencies. Electrical oscillations with a frequency of 40 kHz, partially isolated by the radio sensor circuit, are sent to a bandpass ultrasonic frequency amplifier, amplified by it, and after the amplitude detector they enter a low-pass filter. It has a rollover in the frequency range above 3 kHz. The low frequencies isolated by the filter are sent to a low-frequency amplifier. Telephones and the input of the dial indicator amplifier are connected to the ULF output.

A device with an acoustic sensor is distinguished by the fact that wide-spectrum acoustic vibrations that occur during a spark discharge are converted by a piezoelectric crystal into an electrical signal, which is fed to the input of a bandpass ultrasonic frequency amplifier.

Places of industrial interference are detected as follows: a radio sensor is connected to the device and the presence of radio interference is determined, and their area is determined by the increase in the signal. Then they connect the acoustic sensor and direct the horn towards the probable location of the spark discharge (network insulators, twisted electrical wires, lamps, etc.) and, guided by the increase in the signal, find this place.

The electrical circuit of the device is shown in Fig. 75, b. The device is assembled on eight transistors of the GT109 type and two diodes of the D9B type. Coils L1, L2, L3, L4 are wound with PEV-1 0.15 wire, contain 600, 750, 600, 600 turns, respectively, and are enclosed in SB-23-11a cores. Coil L5 has 700-750 turns of PEV-1 0.15 wire and is wound on a ferrite rod (c = 400, length 100 mm).

The M476 microammeter from the Romantic tape recorder was used as an indicator.

The design of the acoustic sensor is shown in Fig. 75, v. The sensor parts are fixed in the housing with BF-2 glue or some other glue. The piezoelectric element is mounted on three plexiglass stands. It is connected to the membrane with a 1 mm diameter needle. The top of the sensor is covered with a protective mesh.

The horn is made of sheet brass or bronze, the joints are soldered.

A radio sensor with a power source is mounted in the device body. The dimensions of the device are 140 X 60 X 40 mm. The acoustic sensor is assembled separately and has dimensions of 120 X 90 X 90 mm. The weight of the device with an acoustic sensor is no more than 350 g. The device is powered by a D-0.25 battery. Headphones TM-1.

This group of devices uses the physical properties of the environment in which the embedded device can be placed, or the properties of the elements of the embedded devices, independent of their operating mode.

Since long-term remote-controlled embedded devices can be installed in the voids of solid media (brick and concrete walls, wooden structures, etc.), identification and inspection of voids is carried out during “cleaning” of the premises.

In the simplest case, voids in a wall or any other continuous medium are detected by tapping them. Voids in continuous media change the nature of the propagation of structural sound, as a result of which the sound spectra perceived by the human auditory system in a continuous medium and in a void are different.

Technical means for detecting voids can increase the reliability of identifying voids. As such tools, various ultrasonic devices, including medical ones, and special void detectors can be used. Special technical means for detecting voids use:

Differences in the values ​​of the dielectric constant of the medium and the void;

Differences in the thermal conductivity of air and continuous medium:

Reflections of acoustic waves in the ultrasonic range from the boundaries of the “solid medium - air” interface).

In emptiness (air) the dielectric constant is close to unity; for concrete, brick, and wood it is much greater. Dielectrics with different dielectric constants deform the electric field generated by the void detector differently. The change in dielectric induction localizes the void. Thus, the “Kama” void detector detects cavities in brick or concrete walls measuring 6 x 6 x 12 cm and 6 x 6 x 25 cm.

Using an ultrasonic tomograph D 1230, voids with a volume of 30 cm 3 are detected at a depth of up to 1 m, and an ultrasonic thickness gauge D 1220 - with a depth of up to 50 cm.

Thermal imagers are an effective means of identifying voids in walls heated several degrees higher than the air temperature in the room. The sensitivity of cooled thermal imagers reaches 0.01 degrees Celsius, while uncooled ones are an order of magnitude worse. Due to the difference in thermal conductivity of concrete or brick walls and air, the boundaries of voids with air when heating or cooling a room can be observed on the screen of a thermal imager.

The portable uncooled thermal imager TN-3 (“Spectrum”) with a built-in digital processor provides the ability to observe images on the screen in the IR range (8-13 microns) of an object with a minimum temperature difference of its surface elements of 0.15 degrees. The thermal imager kit contains a camera measuring 110 x 165 x 455 mm and weighing 6 kg, a small-sized monitor and a power supply.

Metal detectors detect embedded devices based on the magnetic and electrical properties of their elements. Any bookmark contains conductive elements: resistors, inductors, connecting current conductors in a hinged or microminiature design, an antenna, a battery housing, a metal body of the bookmark.

Based on the operating principle, a distinction is made between parametric (passive) and inductive (active) metal detectors. By design - stationary and manual. To detect small conductive elements, hand-held metal detectors are mainly used, which can be brought close to the conductive element.

In parametric metal detectors, conductive elements that fall within the coverage area of ​​the search frame (coil) with a diameter of 250-300 mm change its inductance. This coil is the inductance of the oscillatory circuit of the search generator, the oscillation frequency of which is 50-500 kHz. The higher the oscillation frequency of the generator, the greater the deviation of the generator frequency, i.e., the higher the sensitivity of the metal detector. But at the same time, the influence of the environment, especially the soil, is stronger. Therefore, in some types of metal detector, the search coil is fed with a non-harmonic signal with a frequency of 15-50 kHz, and harmonics at frequencies of 500-1000 kHz are used to measure the frequency deviation.

To measure the deviation of the oscillation frequency of a parametric metal detector generator, the “beating” method is widely used - a phenomenon that occurs when two oscillations with similar frequencies are added. One oscillation with a changing frequency is created by a search oscillator, the other by a reference oscillator with a stabilized frequency. The frequencies of these oscillations are set equal if there are no foreign objects in the search frame coverage area. The beat frequency is sent as a tone frequency to the headphones and indicator light. Based on the frequency of the sound signal and the flashing of the indicator light, you can localize the area within which a metal object is located.

The advantage of parametric metal detectors is their magnetic selectivity - the ability to separate metals based on their magnetic properties. It is known that ferrous metals (cast iron, steel, cobalt, alloys) have a specific magnetic permeability μ» 1. For non-ferrous paramagnetic metals (titanium, aluminum, tin, platinum, etc.) this figure is slightly greater than 1, for diamagnetic metals (gold, copper, silver, lead, zinc, etc.) - slightly less than 1. Consequently, by the sign and magnitude of the deviation of the frequency of the search generator from the nominal (zero) value, one can judge the type of metal object that is within the range of the frame. This opportunity expanded the scope of hand-held metal detectors, including for searching for treasures, and intensified research on their improvement in the mid-90s of the 20th century.

However, the sensitivity of passive parametric metal detectors is not sufficient to detect metal objects located in a heterogeneous environment. Detection depth is increased in induction metal detectors. A magnetic field is created in them using a special generator and a radiating search frame (coil). It induces eddy currents in conductive objects, creating a secondary field. This field is received by another, measuring, coil of the metal detector. The signal induced in it is filtered, processed, amplified and fed to the sound and light indicator of the metal detector.

There are analog and pulse induction metal detectors. In analog metal detectors, a harmonic signal with a frequency of 3-20 kHz is supplied to the search coil from a generator. In pulsed metal detectors, due to a powerful short pulse supplied to the search coil, it is possible to form a magnetic field with a strength of 100-1000 A/m, an order of magnitude higher than the field strength of an analog metal detector and penetrating up to 2 m into the ground.

Since the magnetic field of the search coil penetrates the measuring coil, the main technical problem of induction metal detectors is the compensation of the signals induced by this field in the measuring coil. Compensation of signals in the measuring coil is achieved due to the mutually perpendicular spatial arrangement of the axes of the search and measuring coils, the use of a compensation coil with parameters identical to the parameters of the measuring coil, but with the opposite direction of wire winding, as well as through appropriate signal processing.

The characteristics of the signal in the measuring coil depend on the size of the conductive surface of the object, its electrical conductivity, the magnetic permeability of the material and the field frequency. Isolation of very weak signals induced in the measuring coil of a metal detector by the secondary field of small metal objects against the background of various interference, as well as compensation for interference, requires rather complex optimal processing algorithms implemented by microprocessor technology.

Hand-held metal detectors are mainly used to detect bookmarks. The measuring and search coils in them can be made in the form of a toroid with a diameter of about 140-150 mm, mounted on the body of the handle (AKA 7202) or directly in the body of the metal detector (“Miniscan”). The metal detector has sound and light indicators, a sensitivity adjustment regulator; power supply of hand-held metal detectors from chemical current sources. The problem of automatically adjusting the gain of a metal detector to environmental parameters is solved by a microprocessor. The maximum sensitivity of a metal detector is characterized by a piece of a needle 5 mm long, located in the field of action of the measuring coil. The weight of hand-held metal detectors is small: from 260 g to several kg.

For interscopy of objects of unknown purpose, portable X-ray units are used. There are two types of portable X-ray units:

Fluoroscopes with images displayed on the screen of a viewing console;

X-ray television installations.

Portable fluoroscopes consist of an emitter, a remote control, a viewing console with a luminescent screen, a battery pack, a charger, connecting cables and bags for carrying the unit (transport packaging). The object being examined is placed between the emitter and the viewing attachment at a distance of about 50 cm from the emitter and close to the viewing attachment.

The penetrating power of X-rays is proportional to the anode voltage on the X-ray tube, which reaches 250 kV in some portable fluoroscopes. For example, the Shmel-90/K inspection X-ray installation from Flash Electronics has an anode voltage of 90 kV to ensure high penetrating power. It shines through a steel plate 2 mm thick, a concrete wall up to 100 mm thick, and allows you to distinguish behind a 3 mm thick aluminum barrier two copper wires with a diameter of 0.2 mm, located at a distance of 1 mm from each other. The working field of the viewing console screen is a circle with a diameter of 255 mm.

In order to increase operator safety, modern portable X-ray fluoroscopes (for example, the Yauza-1 fluoroscope from Novo) use a luminescent screen with memory, which allows you to view the image after turning off the high voltage. Such complexes include a specialized thermal container for erasing images from fluorescent screens.

Reducing the power of X-ray radiation and the weight-dimensional characteristics of the installation is achieved by increasing the brightness of the screen image. The portable X-ray fluoroscope FP-1 (“Spectrum”) with a screen brightness gain of at least 30,000 has small dimensions (270 x 240 x 920 mm) and weight (3 kg). At the same time, the dimensions of its fluoroscopic screen are 250 x 250 mm. Additionally, it comes with a photo or video attachment for documenting images.

To X-ray thin objects with non-metallic bodies, installations with low-level radioactive isotopes are used. Such installations are compact, easy to operate and safe. For example, the RK-990 X-ray microinstallation with dimensions of 220 x 210 mm and a weight of 1.7 kg scans an object with dimensions of up to 63 x 87 mm.

In X-ray television installations, the shadow image is converted into a television image on the screen of a monitor remote from the emitter. For example, the Shmel-Express X-ray apparatus provides the ability to observe an image of an object both on a monitor screen located up to 2 m from the X-ray installation, and on the screen of the viewing console of the Shmel-90K complex. The screen size of the X-ray television converter is 360 x 480 mm. This installation allows you to store up to 1000 images and provides information and technical interface with a PC.

The use of X-ray units for studying embedded devices is limited by their relatively high cost.

If the wires in the house are hidden in the thickness of the wall, then sometimes you have to look for their location. Let's look at how this can be done. A self-assembled device can be an assistant in this matter. You don’t even need to be a professional in the field of electronics or a radio amateur - the simplest circuit for a hidden wiring detector allows any home craftsman to make it.

In our article we will try to avoid complex scientific and technical terms. We will try to write it in a way that everyone can understand. We will not only provide schematic diagrams of hidden wiring finders, along with the names and brands of parts for assembly, but also show how the pinouts of the elements are located.

Although repairing damaged wiring is not very difficult, it is still advisable to avoid it. Therefore, it is necessary to determine the wiring diagram in the following cases.

1. When remodeling a house and moving partitions, moving door and window openings.
2. If we are going to carry out repair work related to the installation of various elements in the thickness of the wall or ceiling. Even when hanging a picture on the wall, you can accidentally touch a wire.
3. If we are going to install heating devices. Although they may not be mounted on the wall, pipes and radiators are not allowed to be adjacent to electrical wires; they must be located at a distance of at least half a meter to prevent damage to the insulation from overheating.
4. When repairing and upgrading the wiring itself (for example, installing additional lamps or sockets).

Of course, you can simply turn off the power to the house and connect the damaged wires, but this is inconvenient and dangerous for many reasons.

• It is impossible to make modern repairs without power tools; if we turn off the power supply, we will not be able to use them.
• When installing fasteners in the wall, we do not know how far away they are from the wires. It is possible that, without noticing, we did not break the wire, but damaged its insulation. Then the self-tapping screw and the metal shelf it secures will be energized.
• There is a possibility that we will damage the ground wire. This is not noticeable, but the devices he was going to and the people using them will be without protection.

Why do you need a wire detector?

Of course, you can find the location of the wires in other ways:

1. According to drawings- they are not always there and no one is insured that there were no deviations from the project.
2. According to the location of electrical appliances, junction boxes, sockets, switches and lamps. They are connected by straight vertical or horizontal lines. As in the previous case, this may not be the case, due to the “fantasies” of unqualified electricians.
3. Carefully opening up the wall trim (especially those with sheet metal trim)- a labor-intensive and costly method. But if you are going to do repairs, then after removing the wallpaper you can often see traces of sealed grooves or bulges in the plaster, under which wires are hidden.

For all the above reasons, it is clear that you cannot do without an indicator of the location of electrical wiring.

Why make an indicator yourself?

For the reason that it is pleasant to use something made with your own hands. At the same time, you can save money. You can also buy the device; its price ranges from 1000 rubles for Chinese models with little functionality to 10 thousand for professional equipment.

The price of parts for self-assembly is an order of magnitude lower. In addition, almost any device circuit for detecting hidden wiring intended for radio amateurs does not contain rare elements; everything can be extracted from broken household appliances.

How does a hidden wiring finder work?

The search for hidden wiring is based on two principles:

1. any conductor under current emits electromagnetic radiation;
2. metal, even non-magnetic (aluminum and copper) affects the external magnetic field.

To search, either a conductor under current is determined by its radiation, or a magnetic field is induced and its change is determined (like metal detectors). Devices can work on one of the principles or combine two, since each of them has its own pros and cons.

Advantages and disadvantages of searching by electromagnetic radiation

The advantages include:

1. the device does not respond to pipes and fittings in the wall;
2. you can find the location of the conductor break;
3. the scheme is simpler.

On the downside:

1. the wires must be live.
2. After the break the wire is not visible.

Sensitivity increases if current flows through the wires (load is connected). If there is no load, then the wire is detected anyway, since alternating current passes through a kind of capacitor (capacitance) between the device and the wiring. Therefore, you can also look for the location of other cables (television, digital) by connecting an alternating current generator to them. This is the method used by signalmen.

Advice. After a break, the wire can be found by connecting the generator on the load side.

Pros and cons of working on the principle of a metal detector

There is only one plus - you can search for unconnected wires and pipes.

More cons:

1. more complex scheme;
2. less sensitivity;
3. It is difficult to find wires in a reinforced concrete wall.

Now let’s look at the hidden wiring detector circuits and their implementation:

Advice. Sometimes, instead of a finder, you can use a simple phase indicator. Its neon light lights up even without contact with the phase wire, when approached.

The simplest scheme

This is the simplest scheme, so we’ll talk about it first, and explain all the little things in more detail (let those who understand not laugh). Anyone can collect it if they want.

1. field effect transistor type KP 103 or KP 303 (designated VT);
2. power supply 1.5-5 V (one or more batteries);
3. electromagnetic telephone (designated SP);
4. wires;
5. any switch or toggle switch;
6. an ohmmeter (designated Ω) or an avometer (tester), although you can do without it.

The only tools you need are a soldering iron and wire cutters. For soldering, naturally, you must have solder, flux or rosin. Now let's talk more about the unclear details.

Field-effect transistor

The most important detail, in the diagram it is indicated like this:

We look at the right side of the figure, the left is not important to us, its conclusions are indicated by letters:

• “Z” - shutter (the direction of the arrow indicates type p or n; we also do not take this into account now;
• “I” is the source;
• "C" - stock.

If no voltage is applied to the gate of the transistor, then there is a large resistance between the source and drain, and almost no current flows. Having applied voltage, we open the gate and reduce the resistance (like opening a tap on a pipe), the current begins to flow. Moreover, field-effect transistors are very sensitive; the hidden wiring detector circuit is based on this feature.

This is what this part looks like in the photo.

Transistor KP 303 has the same appearance, but differs in marking. After the numbers there is also a letter designation, we do not take it into account. A second version is available in a plastic case in the form of a prism and three flat terminals at the bottom.

How the pins are located on the body should be clear from the figure below. On it, a transistor in a metal case is depicted with the terminals down; you need to navigate by the key.

Attention. Field-effect transistors can burn out from electrostatic interference. Therefore, when working, it is advisable to ground the soldering iron and your body (using a metal bracelet and wire).

This is not a telephone set, but only a part of it (the device got its name from here), it looks like this:

They come with a body made entirely of plastic. Suitable for old rotary phones. It is located in the tube in the part that is adjacent to the ear (from which we hear the interlocutor). In order to remove the phone, you need to unscrew the decorative cover and disconnect the wires at the terminals.

The marking is not important to us except the resistance, it should be in the range of 1600 - 2200 Ohms (can be designated Ω).

The phone works on the following principle - there is an electromagnet inside, which, when current flows through it, attracts a metal membrane. Vibrations of the membrane create the sound we hear.

This is a measuring device for determining resistance.

It looks like this:

If it’s difficult to find, then we’ll do without it, the scheme will work just like that. If necessary, you can draw conclusions for connection and use a “tester” (avometer or multimeter - the same thing) during the search in resistance measurement mode. Almost everyone has this device.

Advice. A simple field-effect transistor with clamped terminals (drain and source) in the crocodiles on the avometer probes can serve as an “ersatz finder” for hidden wiring. The Avometer naturally works in resistance measurement mode.

Assembling the circuit

We assemble all the parts using a canopy using wires according to the diagram. We solder a piece of single-core wire 5-10 centimeters long onto the transistor gate. It will act as an antenna.

After assembly, you can pack everything into any suitable case, such as a plastic soap dish.

Looking for wiring

We bring the device turned on to the wall and begin to move the antenna along it. In the place where the live wire is located, a humming noise grows from the phone (like a working transformer). The closer to the wire, the stronger the sound will be.

You can more accurately find the wiring using the ohmmeter readings; when approached, it shows the least resistance. To work with an ohmmeter, turn off the power to the device.

How the device works

The whole point (as we have already said) is the high sensitivity of the field-effect transistor. The electromagnetic field induced on its gate with the antenna opens the transistor. Current is applied to the phone, and it begins to emit sound signals at a frequency of 50 Hertz (alternating current frequency).

An ohmmeter measures the resistance between source and drain. It becomes smaller as the gate signal increases.

Now let's look at more complex devices, without going too deep into the details.

On the chip

A very common hidden wiring finder circuit is based on the K561LA7 microcircuit.

Attention. The microcircuit may be designated without the letter “K” in front - this means that it is not general purpose, but special - of higher quality.

This is a digital chip with the simplest logic, but it works great as an amplifier.

Here is the circuit diagram itself with the pinout of the microcircuit:

The numbers on the diagram indicate the pin numbers.

In addition to the microcircuit itself, we also need an LED. This can be AL307 or its analogs (AL336) with any letter designation and any color, as well as a 3-15 V power supply.

Attention. If we choose a power supply greater than 3-5V, then the current through the LED must be limited by a series-connected resistor of 1-1.5 kOhm.

The principle of operation is simple - a signal from the antenna is supplied to the inputs, as in the previous case, it is amplified. The fact that there is voltage at the input is indicated by the lighting of the LED. Two logic elements (AND-NOT) are connected in series, because the outputs of the microcircuit are inverse, that is, if there is a signal at the input, then there is none at the output and vice versa.

The only disadvantage of this finder is that it does not determine the distance to the wire.

It can also be mounted with a canopy and placed in any convenient building.

Having examined simple circuits of hidden electrical wiring detectors, we will also describe the design for experienced radio amateurs.

Combined hidden wiring finder

This device is a “two-in-one” device that can operate both in electromagnetic radiation search mode and as a metal detector.

Here is his diagram:

The selection of modes is carried out by switch S 1, which can supply voltage to one or another unit; we will consider them in turn.

Metal detector unit

It is located in the upper part (currently disabled according to the diagram) and consists of the following nodes:

• Magnetic antenna on a ferrite rod (WA 1);

• A generator assembled on a KT315 transistor (VT 1) and a second magnetic antenna coil (L2);

• Receiver unit on the first coil of the magnetic antenna (L1), capacitor C2 with a detector on the KD522 diode (VD1);

• Amplifier on microcircuit 140UD12 (DA1);

• Indicator in the form of a KIPMO1B LED (others can be used instead, for example AL 307);
• A pulse generator lasting up to a second based on two logical elements of a digital microcircuit of the simplest logic 561LE5 (D1 1; D 1 2);
• An audio frequency generator on the two remaining elements of the microcircuit;
• Piezoceramic emitter ZP-1 (VA 1).

How does a metal detector circuit work?

• The generator is tuned to a frequency close to the receiver's transmission threshold. Trimmer resistors R2 and R6 are used for this.

Advice. To adjust the device during operation, it is even better to select R2 not as an adjuster, but as a variable one, with a knob displayed on the control panel of the device.

• If there is metal nearby, the settings of the generator and receiver circuits change, and the generator signal passes through the receiver's frequency filter.
• Additionally, the operational amplifier - comparator DA 1 has a response threshold compared to the voltage supplied from the divider across resistors R9, R10 to its second input. If this value is exceeded it starts working. The signal is amplified by the operational amplifier to a level sufficient to be perceived by the generator at D1, D2 as a logical unit and start it. The HL 1 LED is also connected to the output of the amplifier, which, when illuminated, indicates that wiring has been detected.
• The signal from the first generator periodically triggers the audio frequency generator on D3, D4. A piezoceramic emitter connected to the generator output emits an intermittent signal.

Magnetic field search block

To start it, you need to set switch S 1 to the second position. This knot is much simpler. It is assembled on a second operational amplifier DA 2.

An antenna is connected to its input, and a second HL 2 LED is installed at the output. If there is interference (signal) at the antenna, the amplifier will raise its level and light up the connected LED.

Device assembly

We won’t give advice here, as the assembly instructions are useless, the techniques are the same as for installing all radio-electronic devices. It is difficult to make it with a canopy; it is better to use a printed circuit board.

Radio amateurs themselves know how to do everything. But there is one caveat - for stable operation you need to separate the magnetic and conventional antennas as far as possible.

Sometimes, if you don’t have a hidden wiring finder or the time (desire) to assemble it, you can try to find it using other devices.

Let me give you a few examples:

• Let's not forget about Oersted's experiment, which discovered the relationship between magnetism and electricity. The scheme for searching for hidden wiring is as follows - we connect the load and, based on the maximum deviation of the arrow, we find the position of the wires. The main thing is that the current is significant, for example, the iron or vacuum cleaner is turned on.

• A radio tuned to the maximum wavelength can respond to the wiring. The method works especially effectively if there are sources of high-frequency interference in the network.

• An electrodynamic microphone connected to an amplifier; the most common electret microphones today do not operate in this way. You can also use the pickup of an electric guitar by first removing the strings from it. It is better to search using a “single-coil” (narrower, in one row) than using a “humbucker”, which has protection from external interference.

• If you still have a cassette, or even better, a reel-to-reel tape recorder or player, then you can remove their head by removing it and extending the wires and look for the wires, using it to turn on the device for playback.

Attention. The magnetic head must be connected with a shielded wire.

• Some people also try to search for wires using applications on their smartphone. But from personal experience I will say that the method does not work. I used the “Metal Detector” program, so she did not see the closely held wire to which a three-kilowatt motor was connected. Although maybe I'm wrong.

I hope that our article not only gave you the answer to what a hidden wiring finder circuit looks like, but also helped you assemble this device yourself. We are also glad if you understand why you need to know the location of the hidden wires. Make home repairs quickly and safely.