When performing construction work, there is often a need to check the wall for the presence of wiring in it. To conduct a search, you will need a detector that reacts to metal. You can purchase this device in a factory-made version or make a hidden wiring finder with your own hands. This article will discuss the nuances of the internal structure of detectors, as well as methods for their manufacture.

Factory detector circuits

There are several types of factory-made detectors:

1. Electrostatic. The advantages of such a device are the simplicity of the internal structure and the ability to find metal objects at a considerable distance. The disadvantage of the detector is that it can only search in a dry environment. Otherwise there will be false positives. In addition, only those wires that are energized can be detected.
2. Electromagnetic. Advantages include simple circuit design and highly accurate wiring detection. There is only one drawback, but a significant one: in addition to voltage, you need a fairly powerful load - at least 1 kilowatt.
3. Metal detector. This device is a standard metal detector. The main advantage is that there is no need for tension. Disadvantages: detects any metal (not just wiring), and is also structurally complex.

The simplest circuits of homemade devices

There are several schemes of such devices.

With sound indication

You can make a simple hidden wiring detector with your own hands using resistor R1. This resistor protects the circuit from induced voltage. Moreover, even if you install it, this most likely will not affect the operation of the device.

Hidden wiring detector circuit with sound indication

A copper conductor with a length of 5 to 15 centimeters is used as an antenna. When wiring is detected, a specific crackling sound is produced. The piezo element is connected according to the bridge circuit principle, which allows you to control the volume level.

Sound indication combined with light

This circuit is also simple - you only need one chip.

Hidden wiring finder circuit on a microcircuit

Features of the circuit: the value of resistor R1 must be equal to or greater than 50 MOhm. The LED is used without resistance limitation, since the microcircuit performs this task independently.

On a field-effect transistor (first circuit)

Transistors of this group are extremely responsive to an electric field. This feature is used in the diagram below.

Field-effect transistor wiring finder circuit

From the picture you can understand that the device is very simple; you can make it yourself, without using any special devices. The supply voltage indicator is from 3 to 5 V. The current required is so small that the detector can operate for 5-6 hours without shutting down. The antenna coil is fixed with a 0.3-0.5 mm wire to the core, which, in turn, has a diameter of 3 mm. The number of turns depends on the wire itself: 20 turns for a 0.3 mm wire and 50 turns for a 0.5 mm wire. The antenna can function both with and without a frame.

On a field-effect transistor (second circuit)

Another option for making a hidden wiring detector with your own hands using a field-effect transistor is to use the KP103 microcircuit. This field grass is characterized by high sensitivity. If its gate is in close proximity to the wiring, the resistance is reduced, which leads to the opening of other transistors. After this, the LED begins to glow.

Note! Polevik KP103 can be used with any letter, just like the AL307 light diode. The fact is that bipolar transistors with such conductivity have low power, and the transmission coefficient must be significant. Therefore, instead of KT203, it is recommended to choose KT361.

The device is small in size - assembly can be carried out even in a marker housing. The antenna extends through the hole in the marker. The antenna length is from 5 to 10 centimeters. However, if the wiring is not too deep in the wall (no deeper than 10 centimeters), you can get by with the length of the field-effect transistor leg.

Hidden wiring detector circuit using transistor KP103

The KP103 transistor is installed horizontally, and the gate must be bent so that it is located directly above the transistor body.

Metal detector

Schematic diagram of a metal detector

The metal detector circuit looks like this:

• frequency generator (100 kHz) - VT1;
• detector - VT2;
• indication - VT3, VT4.

Generator coils are wound on a ferrite core. The rod diameter is 8 millimeters. The number of turns on the first coil is 120, on the second - 45. The wire is selected as PEVTL 0.35.

The metal detector should be adjusted away from metal products. The adjustment is made using trimming resistors R3 and R5 in such a way that the generation practically disappears (uneven glow of the diode and low brightness). Next, the R3 tincture occurs in order to extinguish the emitter.

The next step is to adjust the sensitivity. This is done using a piece of metal (you can use a coin) and a pair of resistors. Moreover, it is recommended to repeat the sensitivity adjustment periodically. To optimize the process and make it more convenient, regulators can be built into the body of the metal detector.

The configured device turns on when the antenna is close to metal - the light diode begins to blink.

Wiring alarm without batteries

This detector uses the network directly as a power source. This circuit is possible through the use of a high-capacity capacitor (indicated in the diagram as C1). The capacitor is charged from the network. In a charged state, the capacitor transmits a voltage of 6-10 V. In this case, only the brightness of the light diode depends on the voltage, but this indicator does not affect the sensitivity of the device.

Schematic diagram of a hidden wiring finder without batteries

Wiring detector on microcontroller

The diagram above shows a hidden wiring detector built on a PIC12F629 microcontroller. The operation of the device is based on responsiveness to a magnetic field. This field is formed by current flowing through a conductor located in the wall.

The circuit can use an LED lamp or a piezo emitter. When a magnetic field is detected, a lamp lights up or a piezo emitter begins to crackle, depending on the preferred type of indication.

The advantage of the device is its ability to respond only to a frequency of 50 Hz, which is the frequency of alternating current. Thus, false alarms of the finder are excluded, since the device will not respond to other frequencies.

Two-element indicator

Schematic diagram of a two-element detector

In this case, you need a microcircuit and a light diode. You can choose DD1 as the microcircuit, and it is recommended to take HL1 for the LED. The task is to connect the leads in such a way as to create three inverters in a circuit. As a result, the device will amplify the currents that flow to the device from the alternating current field in the wiring located in the wall. When wires are detected, the diode lamp begins to glow. When moving away from the wall or breaking the chain, the lamp goes out.

There are two options for implementing the circuit:

1. Connection of terminals: third to eighth, second to tenth, fourth to seventh and ninth, first to fifth, eleventh to fourteenth.
2. Connection of terminals: third with eighth, tenth with thirteenth, first with fifth and twelfth, second with eleventh and fourteenth, fourth with seventh and ninth.

Industrial circuits of professional detectors

You can assemble a professional-level device at home. However, such equipment has a rather complex design, and its manufacture will require a lot of effort. Below are two diagrams to choose from: the first refers to an industrial device, the second to a home-made Woodpecker device.

Scheme of an industrial signaling device for hidden wiring
Scheme of a homemade wiring detector “Woodpecker”

You can also make a device like YADITE 8848. Below are two options for such a device.

Schematic diagram of the detector on TC4069UBP
Wiring locator diagram for 74HC14AP

Checking homemade wiring finders

Before using a homemade device, it is recommended to test its performance. Checking will show correct assembly.

The test is performed as follows:

1. We find an area where there is definitely hidden wiring. For example, it is guaranteed that there are wires in the wall leading to switches and sockets.
2. We check the selected area. To do this, we bring the device to the wall and observe the indication.
3. If the signal is received only at the point where the cable passes, the device is working properly and can be used.
4. If the signal appears and disappears in different directions, it means the device is faulty.

Advice! Before starting the test, the wiring must be subjected to maximum stress. To provide such a load, we connect as many electrical appliances as possible to the network. As a result, the magnetic and electric fields to which the devices respond are enhanced.

So, it is not necessary to purchase a wiring detector in a store. This device can be made at home if you follow the above diagrams.

There are situations when you need to detect wiring embedded in a wall or find damage to it. For this purpose, a hidden wiring detector is used. It comes in three types:

• Electrostatic. Pros: simple design, long-range detection. Cons: search only in a dry environment, otherwise it shows the presence of wiring; voltage is required on the desired conductors.
• Electromagnetic. Pros: the circuit is also simple, detection accuracy is high. Disadvantages: in addition to voltage, a powerful load (from 1 kW) is required to be connected to the wire.
• Metal detector. This is a regular metal detector. Pros: No voltage required. Cons: shows any metal. Even a hammered nail will interfere with the search for wires. Complex design.

• Detector circuits
• The simplest schemes
  • With sound indication
• On a field effect transistor
  • Broken Wire Finder
• Metal detector

Detector circuits

There are many different schemes for this device. They can differ both in the complexity of the design solution and in their functional purpose: simply detect wires, or specifically look for breaks in electrical wiring.

The simplest schemes

With sound indication

The first drawing is the simplest device. Resistor R1 is there to protect the microcircuit from induced voltage, although if it is not installed, as practice shows, nothing bad will happen.

A copper conductor 5-15 cm long is used as an antenna. When a wire is detected, a characteristic crackling sound will be heard. It is easy to find which lamp on the Christmas tree garland has burned out: near it the crackling will stop. The piezoelectric element is connected via a bridge circuit. This allows you to increase the volume.

Sound and light indication

The circuit is also very simple, assembled on a single chip.

Features: resistor R1 must have a value of at least 50 MOhm. The LED stands without limiting resistance: the microcircuit itself copes with this task perfectly.

On a field effect transistor

Such transistors are very sensitive to the electric field. It is this ability that we will use in the following schemes.

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It can be seen from the figure that the device is very simple and can be easily assembled with your own hands without any special tools. The supply voltage is 3-5 V. The current consumption is so low that this wiring detector can operate for up to 6 hours without shutting down. The antenna coil is wound with a 0.3–0.5 mm wire on a core with a diameter of 3 mm. How many turns depends on the wire: 0.3 mm - 20 turns, 0.5 mm - 50 turns. The antenna works both with and without a frame.

Setting: you need to select the value of R1 so that the speaker volume is maximum. The transistor can be replaced with an analogue - KP303D. The presence of metal in the path of the probe does not affect its operation.

Broken Wire Finder

This device is so compact that it can be assembled in a marker housing. The antenna extends through a hole in it. Its length is 5-10 cm, but if the electrical wiring is located shallowly in the wall - no deeper than 5-10 cm - then the length of the field-effect transistor leg will be sufficient.

Field grass VT1 is used as a sensor. His sensitivity is strong. When its gate is close to the electrical wiring, the drain-source resistance will decrease. This will cause the other two transistors to open and the LED to light up.

Polevik KP103 will suit any letter; LED – AL307, the letter doesn’t matter either. Bipolar transistors - whatever is available, of similar conductivity, low power. Select the transmission coefficient as high as possible. For example, instead of KT203 you can use KT361.

Please note: when installing the KP103, it is placed horizontally, and its shutter is bent so that it is above the transistor body. It is very easy to assemble such a wiring finder with your own hands.

Metal detector

Before carrying out any construction work, it can be useful to scan the walls for the presence of any metal inside. These can be either elements of building structures or the result of builders’ carelessness: fittings, electrical wiring or anything else. This device has average assembly complexity.

Search depth: a small nail will be detected at a depth of up to 5 mm, a water pipe - up to 200 mm, electrical wires - 20-30 mm.

The circuit is as follows: VT1 – frequency generator (100 kHz), VT2 – detector, VT3, 4 – indication. The generator coils are wound on a ferrite core. The diameter of the rod is 8 mm, the first coil (L1) is 120 turns, the second (L2) is 45. Wire grade is PEVTL 0.35.

Now let's talk about how to set it up. This should be done away from metal objects (don’t forget to remove the watch from your hand). Using trimming resistors R3 and R5, you need to adjust the device so that the generation almost stops (the LED glow is uneven and the brightness is very low). After this, only R3 is adjusted so that the emitter goes out. When everything is done, we move on to the next stage: we take a piece of metal (you can use a five-kopeck coin), and use both resistors to achieve maximum sensitivity.

It is advisable to carry out such adjustments from time to time. For convenience, you can display the regulators on the body of the metal detector.

As a result, when the antenna moves along a metal object, the LED will blink.

The above examples show that such a detector is an item that does not necessarily need to be purchased in a store. With a lot of desire and some experience, all this can be easily assembled with your own hands and copes well with the assigned tasks. Now you can safely do home renovations without fear of driving a nail in the wrong place!

When carrying out repairs or even when it is necessary to hang a clock or a picture on the wall, the work contractor has to deal with the problem of hidden cables. Of course, when laying wiring in a new house or apartment, it is advisable to draw up a diagram of its location. And such a problem will not arise in the future. However, if the repair was not major or the layout of the cables in the walls has long been lost, it is advisable to check the drilling location using a special device - a “finder”. “Finder” will help you check the drilling location

Classification of devices

There are three main types of hidden cable detectors:

• electrostatic, one of the simplest devices;
• electromagnetic, which do not react to all wires, but only to cables with a connected load;
• metal detectors that detect the presence of metal parts.

Another frequently encountered option is a combined wiring finder, which uses several methods for searching at once. Each type of these devices has its own advantages and disadvantages. And, if you have experience and desire, all of them can be made on your own.

Electrostatic finders

Devices of this type allow you to detect the electromagnetic field from live wiring. The design of these finders is the simplest. And the features of working with them include:

• the need for current in the wires. If the power is turned off, the cables cannot be detected;
• When working with the detector, you should first set the appropriate sensitivity. Otherwise, you may not detect wiring that is too deep or, conversely, constantly react to false alarms;
• Searching for wires in damp walls or inside structures with built-in fittings most often does not lead to a positive result.

The popularity of the devices is due to their low cost and acceptable efficiency. The list of devices of this type frequently purchased by consumers includes the well-known model Woodpecker E121, and a number of other inexpensive devices. However, you can also make them yourself - it will be even cheaper than buying a ready-made device, and will not take too much time.

Electromagnetic devices

Signaling devices of this type allow you to locate wiring based on the electromagnetic radiation emanating from it. Like electrostatic equipment, they detect hidden cables only when energized. Moreover, for guaranteed detection it is required that some kind of electrical appliance with a power of at least 1000 W be connected to this line - which cannot be done if the hidden wire is not connected to the outlet.

Metal detectors

Metal detectors can be called one of the most effective detectors. With their help, you can detect wires even when the voltage is turned off. However, they also have a certain drawback - along with searching for metal cables, the devices also react to other metal that may be inside the wall, floor or ceiling. And by reducing the sensitivity of the equipment, you may simply not notice a sufficiently buried cable.

The principle of operation of the equipment is based on the creation of an electromagnetic field that causes disturbances inside the metal wire. The detector reacts to most metals and can be used to search not only wiring, but also other hidden parts - from screws and bolts to fittings. The cost of such a device is higher, and it is more difficult to make it at home.

Combination devices

Combined type equipment combines several (usually two) types of detectors. This significantly increases the efficiency of the search, making it possible to guarantee that there will definitely not be a single hidden cable at the drilling site. One of these devices is the TS-75 finder, the circuit of which combines a metal detector and an electrostatic version.

Equipment price

The cost of wiring detectors varies depending on models, brands and functionality. In addition, the amount that will be spent on purchasing such a finder depends on the purpose of the device, which can be domestic or industrial. It is also worth considering the country in which the device was released.

Chinese-made devices (especially of a little-known brand) will cost less - but will not necessarily serve their owner for at least several years. And European models with similar characteristics can be purchased at 3-4 times more expensive - but their sensitivity will be higher and their service life will be much longer.

You should know: Some homemade detectors may be more effective than budget factory models.

DIY finder

For home use, a do-it-yourself hidden wiring finder is usually sufficient, the circuits of which can be called budget. And, although high accuracy cannot be achieved using such a device, its capabilities are sufficient to search for most cables inside walls and other structures. As a result, the owner of this device will receive certain savings on the purchase of an expensive detector, and will prevent damage to the electrical wire during repair work.

To assemble the easiest finder to make, you will need to prepare:

• a microcircuit that is sufficiently sensitive to electromagnetic or electrostatic radiation. For example, you can take the K561LA7 model, the purchase of which will not cause much damage to your budget;
• a piece of copper wire from 5 to 15 cm long, which will be used as a detector antenna. The best option for such a finder is an 8-centimeter segment;

3. Find a suitable housing in which the circuit will be placed, install it inside, leaving space on one side for the sound source;

4. Install a switch in the circuit, thanks to which the device can be turned on and off without removing the battery.

A properly assembled device quite effectively detects hidden wiring. When brought close to the walls, inside of which there are hidden cables, the hand-assembled device makes a slight cracking noise.

Other search methods

You can find wires hidden in enclosing structures without assembling the detector, which may require some experience in the manufacture of radio devices. To do this, use the following methods:

• visual identification of wires (tearing off wallpaper);
• using a radio receiver to search. The device is tuned to a frequency of 100 kHz, after which it is carried out near the wall. Where the hidden wire is laid, the receiver begins to make noise;

• identifying cables using sockets located on the walls. As a rule, wires run from electrical points in a straight line to the nearest corner.

Another scheme involves connecting a reel-to-reel electromagnetic microphone to a computer or tape recorder. The device may make a buzzing sound where the cable is laid. And owners of smartphones with Android OS have one more additional way - download the special Metal Sniffer program and try to use the phone as a metal detector. The operating principle of such a smartphone detector is based on the presence of a built-in compass for navigation in most models.

Summarizing

Having a hidden cable detector in your apartment or house will increase the safety of repairs. And, if it is not possible to purchase an expensive finder, it can be replaced by a home-made device. Although its efficiency will be lower, and it will most likely not be possible to find the cable inside a reinforced concrete wall.

Drilling a hole for a dowel screw or nail in the wall is not difficult. The main thing is that when perforating, do not stumble upon hidden wiring and damage it. A hidden wiring detector helps detect a break or a live electrical cable in the wall. In order not to spend extra money, we will construct a simple detector based on the K561LA7 microcircuit, and talk about the selection criteria and advantages of factory-made devices.

Homemade detector with a piezoelectric element - simple words about the complex

Hidden wiring detectors are divided into low and high class devices. A low-class device is designed to search for electrical appliances and live wiring. A high-class detector has greater sensitivity and advanced functionality. Such a device is used to determine the breakage of hidden wiring and detects the location of wires without voltage.

You can make a hidden wiring detector with your own hands from available materials by purchasing several small parts. When designing this device, keep in mind that it is suitable for detecting live wiring in a wall. And if you need high-frequency equipment to detect a break and the exact location of a cable down to the millimeter, purchase a high-quality detector in the store.

To assemble the device you will need the following set of elements:

• microcircuit K561LA7;
• 9 V Krona battery;
• connector, battery connector;
• current limiter (resistor) with a nominal resistance of 1 MΩ;
• sound piezoelectric element;
• single-core copper wire or wire L= 5–15 cm;
• wiring for soldering contacts;
• a wooden ruler, a power supply box, and another homemade structure for laying the chain.

Additionally, for work you will need a low-power soldering iron up to 25 W, so as not to overheat the microcircuit; rosin; solder; wire cutters Before we begin assembly, let's take a closer look at the main elements. The main part on which the assembly takes place is a Soviet-type K561LA7 microcircuit. It can be found on the radio market or in old stock. The K561LA7 microcircuit is sensitive to static and electromagnetic fields created by electrical devices and conductors. The current level in the system is controlled by a resistor, which is located between the integrated circuit and the antenna. We use single-core copper wire as an antenna. The length of this element affects the sensitivity of the device and is selected experimentally.

When selecting the length of the copper wire, ensure that it only responds to the electrical cable. This will allow you to determine the exact location of the wiring in the wall.

Another important assembly detail is the piezoelectric element. Catching an electromagnetic signal, it creates a characteristic crackling sound, which signals the presence of wiring in a given location. It is not necessary to specifically purchase the part; take out the speaker from an old player or toy (Tetris, Tamagotchi, watch, sound machine). Instead of a speaker, you can solder headphones. The sound will be cleaner and you won't have to listen to the crackling noise. As an indicator of hidden wiring, you can additionally install an LED element into the device. The circuit is powered by a 9-volt Krona battery.

To make it more convenient for you to work with the microcircuit, take cardboard or foam plastic and mark with a needle the places for attaching the 14 legs (legs) of the part. Then insert the legs of the integrated circuit into them and number them from 1 to 14, starting from left to right with the legs facing up.

We make connections in the following sequence:

1. 1. Prepare a box where we will place the parts after assembly. For a cheap alternative, use a plastic bottle cap. Make a hole in the end with a knife with a diameter of about 5 mm.
2. 2. Insert a hollow rod into the resulting hole, for example, the base of a ballpoint pen, suitable for the diameter, which will serve as a handle (holder).
3. 3. Take a soldering iron and solder a 1 MΩ resistor to pin 1–2 of the microcircuit, covering both contacts.
4. 4. Solder the first speaker wire to leg 4, after which we close legs 5 and 6 together, solder them and connect the second end of the piezoelectric element wire.
5. 5. We close legs 3 and 5–6 with a short wire, forming a jumper.
6. 6. Solder the copper wire to the end of the resistor.
7. 7. We pull the wires of the connector (battery connector) through the handle. We solder the red wire (with a positive charge) to leg 14, and the black wire (with a negative charge) to leg 7.
8. 8. From the other end of the plastic cap (box) we make a hole for the copper wire to exit. We place a microcircuit with wiring inside the lid.
9. 9. Close the lid on top with the speaker, fixing it on the sides with hot glue.
10. 10. Straighten the copper wire vertically and connect the battery to the connector.

The wiring detector is ready. If you have connected all the elements correctly, the device will work. If possible, we recommend equipping the system with a switch or removing the battery from the connector after finishing work in order to save power and not overload the system.

A device with an LED is the second option for assembling the system

The simplest device for finding hidden wiring with an LED indicator is assembled according to a similar scheme. To assemble the system you will need: an LED, a 9 V Krona battery, thin wires, a copper wire (5–15 cm), a connector for the battery (connector), a connector for the microcircuit and the K561LA7 microcircuit itself. The set of tools is unchanged - low power soldering iron, rosin, soldering, wire cutters.

We solder the antenna (copper wire) so that it closes pins 1 and 2 of the microcircuit. We close legs 3, 5, 12 and 13 together, first soldering the horseshoe loop. After this, we make a jumper from the wires for legs 4, 8 and 9. Next, we connect the LED, an indicator of hidden wiring, with a positive charge to the 14th leg, and a negative charge to the 7th leg. We solder the battery connector (connector) (–) to the 7th leg, and (+) to the 14th leg. We close the assembled K561LA7 microcircuit with the connector, first bending the legs inward. We insert the battery into the connector and check the device. When the detector antenna is brought close to hidden wiring, the LED lights up. To make the device more neat and convenient, place the assembled circuit in a box, for example, from an old power supply, making the necessary holes for the output if necessary.

Groups of detectors - types and purpose

All detectors for detecting wiring are divided into 4 types: electrostatic, electromagnetic, metal detectors, combined (universal) types. Let's look at each group.

Electrostatic devices belong to the budget class. They are easy to use, but have a small range of capabilities and are only suitable for detecting live wiring. Also, the device often malfunctions, reacts sensitively to the presence of foreign metal objects in the wall, and operates in a humid environment. This device is optimal for searching for wiring in an apartment. In damp rooms (bathrooms, basements, balconies, bathhouses), the quality of the electrostatic detector will be extremely low.

Electromagnetic detectors are of higher quality and more reliable in operation. Such devices are used to search for de-energized wiring and at low voltage, although errors cannot be excluded. To obtain accurate readings, the load in the circuit when operating electromagnetic detectors should be about 1 kW.

Metal detectors are also used to detect wiring inside walls. However, their main problem is that the wiring finder reacts to the presence of all metal objects, be it a nail or a screw, which is why the accuracy of the device in detecting the exact location of the wiring is reduced. Detecting hidden wiring without voltage using a metal detector gives good results. The signal is given by sound or a flashing LED.

The most accurate results are obtained with combined (universal) models that combine the functions of all previous devices. Universal detectors allow you to find out not only about the location of the wiring, but also its depth, the type of metal in the wire strands, and the presence or absence of voltage. Multidetectors belong to a series of combined options. In addition to wires, they find plastic pipes, wooden elements and non-ferrous metal structures in the wall.

Choosing a device in a store – what to look for?

To decide which detector is better, we present the main characteristics by which the device is divided into quality and functionality. When choosing a device for detecting hidden wiring, pay attention to:

• scanning depth;
• type of signal (sound or color);
• the ability to detect a break;
• difference in types of structures and wiring in the wall.

Scanning depth is one of the main indicators of a quality device. The budget determinant reacts to the location of hidden wiring at a depth of 1–2 cm or, in other words, the occurrence of wiring under a layer of plaster. This indicator is not enough for working at home, so for correct operation we recommend purchasing a detector that scans wiring in the wall to a depth of 5–6 cm. Wires in apartments and private houses are rarely laid deeper, so you should not overpay for this parameter.

When choosing the type of signal, give preference to combined options with a sound and color signal. This choice allows you to reduce errors to a minimum. Pay special attention to the transmission of the sound signal, choosing devices with a change in tone. As the detector approaches or moves away from the wiring, the sound melody changes from low to high and vice versa. If you need accuracy, choose a detector with an LCD display, it allows you to locate hidden wiring with details. Information is displayed on the screen in the form of icons and bars. Regardless of the type of device, it must be tested before purchasing.

When choosing a simple design for one-time work, focus on purchasing an electromagnetic detector. The indicator screwdriver is a classic example of such a device. For correct operation, use contactless battery-powered devices that can pick up weak signals. The appearance of an indicator screwdriver does not affect its quality, but only its convenience. This device is suitable for detecting hidden wiring under a thin layer of plaster. For searching in concrete and brickwork, look for other options.

In addition, the electromagnetic device is not suitable for use in damp rooms and conditions. If this parameter is important to you, consider purchasing a universal device. Such detectors have advanced functions, we recommend that you familiarize yourself with them. You may not need full functionality, so before buying expensive devices, consider the purpose of use. For one-time work, an indicator screwdriver or a simple electrostatic device is sufficient. In professional daily activities, you cannot do without a universal device.

Bosch, Black&Decker detector - a brief overview of popular series

If you are looking for a high-quality, middle-class device for hidden wiring, experts recommend Bosch detectors. Among the series of this manufacturer, the Bosch GMS 120 Prof model is distinguished. What makes it special? It has a deep scanning, about 12 cm, detects metal objects (copper, steel, ferrous metal), live wiring, wood, plastic pipes. Wide functionality allows you to select scanning material. A signal about the location of the desired item is given by sound and color. Additional functions include the ability to mark points for perforation in the wall. Bosch GMS 120 Prof runs on regular batteries. The main advantages of the device: simple interface, convenient adjustment of control modes, point measurement, complete display of information about the object and deep scanning.

Black&Decker devices are also widely used among craftsmen for detecting hidden wiring and searching for dissimilar materials, with the exception of wood. Consider the BDS200 model. It has mode adjustment, which allows you to control the sensitivity of the device, and a shockproof housing. Black&Decker BDS200 is equipped with a sound and color signal, which is displayed on the device display.

Woodpecker device – what does the Russian manufacturer offer?

To determine hidden wiring, technicians use a device from the domestic manufacturer Dyatel. Three main advantages of the detector: quality, affordable price, availability of basic functions for operation. How does the device work? The device reacts to the predominance of the electrostatic field; when it hits resonance, the device emits a sound signal, which intensifies as it approaches the hidden wiring. However, the device only detects vibrations coming from the live wire. The Woodpecker detector does not detect a de-energized cable. The device has a built-in regulator and a self-monitoring mode that controls the sensitivity of the detector. The device is lightweight, weighing no more than 250 g. The detector is suitable for determining:

• hidden wiring in all ceilings (walls, ceiling, floor);
• broken wiring;
• correct connection of the electric meter circuit, without removing seals and terminal blocks;
• phase wire;
• voltage in the contact network;
• ungrounded installation;
• electromagnetic fields created by household appliances;
• correct operation of fusible parts and fuses.

In order for the purchased detector to please you with stable operation, we take into account the following features. The wiring is laid in a vertical and horizontal position. To make the search for hidden wiring faster, we move in these directions. At the point with the highest signal level we put a mark and move the antenna a little further from it. The electrical cable is located between the two points. If the signal has the same intensity throughout the entire area, it is possible that, in addition to the electrical cable, there is a metal structure in the ceiling, for example, a sheathing. To reduce sensitivity, place your hand against the wall.

If you intend to hang a picture or, say, a clock on the wall, then the only thing you will think about is which wall to place it on and whether the new element will fit into the interior of the room. But did you know that not all walls can be drilled or nailed? And the point here is not at all in the characteristics of the material used in construction, but in the electrical wiring. You must know exactly where the wires hidden in the wall lie so as not to damage them.

There are several ways to determine the location of the electrical cable: study the network wiring diagram or find the technical documentation of your home, but if none of this is available, then pay attention to the junction boxes from which the cables go to switches and sockets. If the wiring in the apartment was done by an experienced electrician, then the cables are most likely located at right angles.

It’s good if you have previously replaced the old wiring and know about its current placement. But what happens when the previous owner did not follow or even know the basic rules of electrical wiring? After all, it often happens that, for the purpose of dubious savings, the wiring is laid along the shortest path - diagonally along the wall. In such situations, you cannot do without special search devices.

Today, radio stores sell special devices called detectors (often finders) of hidden wiring. All of them are divided into two groups.

1. Budget devices, which are relatively cheap, determine the location of the source of electromagnetic waves. Such sources include household appliances and live wiring.
2. Expensive, high-class finders are distinguished by increased accuracy and functionality - they are able to find wires regardless of whether they are energized or not.

Do-it-yourself hidden wiring finder: manufacturing technology

For household use, a primitive homemade detector will suffice. As you probably already guessed, the circuit described here is a budget one, so, unfortunately, a high-precision device cannot be made using it. Nevertheless, such a homemade detector will help you avoid making mistakes during repair or construction work, or when you want to decorate a wall with a beautiful painting, etc.

To make a wiring finder, you will need only a few radio components, which are quite easy to find if desired.

Chip

This is the main component of the device, on which, in fact, it will be assembled. For this, use a Soviet-era microcircuit - K561LA7. It is sensitive to static and electromagnetic waves emanating from electrical appliances and electrical conductors. All fields in it are protected from high electrostatics by a special resistor - a kind of intermediary between the microcircuit and the antenna.

Antenna

For the antenna, take an ordinary copper wire (6 to 15 cm long) per core.

Note! In order for the finder to work stably, but its sensitivity to be at the proper level, it is advisable to choose a “golden mean”, namely, choose an antenna length of 8 cm.

At the same time, remember one important nuance: if the length exceeds 10 cm, then there is a risk that the microcircuit will go into self-excitation mode. This will most directly affect the correct operation of the detector: even if an electrical cable runs deep in the plaster, the device may not respond to this.

If the finder is not working properly, you can experiment with the antenna length. Its (length) can be made larger or smaller than the recommended parameters. If the meter eventually stops responding to everything except the wiring, then you've finally found the length you need. If the antenna length is incorrect, the device will respond to any touch.

Let's move on to the next component of the finder - the piezoelectric element. It is necessary to determine by ear when the detector picks up electromagnetic waves (a characteristic crackling sound will be heard). It won’t be difficult to get a piezoelectric element - take it from an old Tetris game, an electronic watch or a Tamagotchi. If you don’t have any of this, don’t despair - replace this element with a milliammeter (take it from an old tape recorder).

Note! When using both at once, the crackling noise will be heard somewhat quieter.

The entire structure will be powered by nine-volt voltage; for this, prepare a Krona-class battery before assembly.

Assembly of the structure

You can perform the assembly procedure in one of two possible ways:

• using a printed circuit board;
• through a wall-mounted installation.

The second option will be preferable for a primitive circuit that consists of five elements.

First stage. To begin, take a sheet of cardboard and place the chip face up on it. The legs will be at the bottom and under each of them you need to make holes with a needle (fourteen in total, seven on one side). Having prepared a place for the microcircuit, insert its legs into the corresponding holes and bend them from the outside - this way you will not only securely fix the IC on the cardboard, but also simplify your further soldering of wires.

Second phase. For the next stage (soldering), use a soldering iron that is not too powerful so as not to overheat the microcircuit. The best option is a 25-watt device. Assemble the finder according to the diagram given in this article. If you do everything correctly, the finder will work immediately, without any additional settings.

Third stage. Find any case of suitable size for the device and build the circuit there. Make a special small hole in the body for the beeper, and fix the piezoelectric element on the other side.

Note! Install a special toggle switch in the power circuit so that the device does not function constantly. Turning this toggle switch on/off will allow you to reboot the detector, taking it out of the self-excitation stage.

Traditionally, we finish the assembly technology with informative video material. It demonstrated testing of “handicraft” and factory finders. It turns out that a product assembled with your own hands more accurately determines the location of hidden electrical cables.

Video – Wiring detector

Operating a hidden wiring finder

The operating principle of all detectors is the same, regardless of whether it is a factory model or a homemade one. First, activate the device using the toggle switch, and then move it along the wall in those places where wiring potentially runs. If the device works properly, it will be able to detect wiring even in the thickest walls and will make a characteristic crackling sound.

Other methods for detecting electrical cables

Method one. The most primitive way to detect wiring. You just need to tear off the wallpaper and find it visually. Of course, this is acceptable only in cases where renovation of the premises is planned and there can be no need to save finishing materials.

Method two. A classic of sorts. Previously, when hidden wiring searchers did not yet exist, they were found using a conventional radio receiver. The receiver was tuned to a frequency of 100 kHz and passed near the very surface of the walls. Where the wire ran, the device began to make a specific noise (often hissing or something like that). This method has been widely used by professionals and electricians, hence there can be no doubt about its effectiveness.

Note! When looking for hidden wiring, first look at the outlets. In most cases, the cables run under or over the outlets.

Method three. You can use a microphone to identify wiring. Where the wiring goes, the microphone speaker will begin to “buzz” (of course, the device must first be connected to something in order to hear the “buzz”).

The best option in this case is an electrodynamic coil microphone. Connect it to a computer, tape recorder or other device that can pick up and play a signal from it. Move the microphone along the wall: in the place where the wiring is going, it will emit a “buzz” with a frequency of 50 Hz.

As you can see, this is essentially the same procedure as with the radio receiver.

Method four. Use a small magnet and tie it to a rope. But in panel buildings or on ceilings, this method, alas, is useless.

Method five. A very specific method of detecting wiring, which will require a hearing aid (a special device for people with poor hearing). With the help of such a device, the background at 50 Hz can be heard perfectly, and the break will always be clear.

Method six. In this case, you will need a KP-103 transistor, the “input” and “output” of which should be connected to a pointer ohmmeter. Start moving the transistor along the wall - where the hidden wiring runs, the “input”-“output” resistance will decrease.

Warning! All activities related to electricity should only be carried out by qualified personnel.

As a conclusion

If your house has a hidden wiring detector, then you don’t have to worry about possible damage to the electrical network, since you will always be able to detect the location of the cables. But know that such a detector is far from the only detection method; there are others. More primitive, but no less effective.

Good luck in mastering this difficult craft - radio electronics!

By the way, read also the article - finding hidden wiring with your own hands.