Citizen K. has long dreamed of settling somewhere in nature, far from the noisy bustling civilization of a big city, among the peace and quiet of the harmony of the world. And now his dream came true: he bought a small plot of land on the outskirts of the village for construction, in a good location and even with a small abandoned garden ... but then he had to face such a problematic issue as finding pipe and cable lines, because he did not know where they are located:
- During construction, you can damage them, and if the cable is energized, then endanger your own life;
- You can forget about connecting to electricity, gas and water supply, not knowing where it goes.
But how to find these ill-fated lines? To tear up all the soil and search at random? .. Not at all! You just need to turn to the help of such a useful device as a line finder, which allows you to find lines quickly and safely. Today, the device can be purchased at every specialized store, you can make a route finder with your own hands. And how, we will tell further. But, first, it is worth figuring out: what kind of device is this, a locator.
A bit of theory
So, the locator is a unique device that allows you to detect the line of passage of a cable or the occurrence of pipes. Modern devices are divided into two types according to the principle of operation;
- contact principle;
- Induction variety.
The contact principle is used in the event of a live cable break.
The device, operating on the induction principle, is able to determine both the live cable and the passive tracing, that is, underground communications that do not give active signals. The induction method is more complex and is based on capturing high frequencies by the device and recording these indicators on a special indicator.
Locators are also divided into single- and multi-frequency. The first ones are the most acceptable option, such devices are easy to mount on their own, and they are used to determine communications located under the ground in the case when some routes do not intersect others, and, thus, the signals emanating from them do not overlap.
Multi-frequency devices are a more complex design and are used to determine trace signals in the case of a high density of cable lines and pipelines. Multi-frequency devices are able to determine the frequency specified in the program without straying to others. Modern devices are equipped with software, which greatly facilitates the work, which for the user consists in one press of a key and reading the information received on the indicator.
Assembly technology
The device has a simple design and consists of two components - a receiver, which receives a signal, and a generator that regulates the operation of the device. The stronger the generator, the more powerful the device will be and the greater the range of the distance at which it is able to determine the lines. So, a device powered by a 24 V battery is able to trace the terrain for 4 km and work for about a hundred hours uninterruptedly. A diagram of a locator operating on this principle is shown below.
As can be seen from the drawing, the device is completed as follows: a modulator and a generator are assembled on the transistor T1, P14. Under the conditions that the switch comes into the open state, the transistor with the base circuit creates a generator with a frequency of 1 kHz. And when the circuit is turned on, even partially, it becomes possible to increase the load on the device. Thus, when the capacitor is turned on, the power of the generator increases sharply, and it begins to work in the VHF range.
To design a cable line locator with your own hands, you need to carefully work out its second part, the receiver.
Here the most important condition is the fact that the magnetic antenna is tuned to the voltage of the sound frequencies of the generator. The signal passing through the transistors creates a stable circuit, and the transistor stages provide the necessary amplification, which ensures uninterrupted operation of the device.
To mount the cable tracer with the diagram shown above, you will need the following:
- We take a getinax board, which will be the basis of the future device.
- We install the power terminals on the front panel.
- We wind the first transformer on a ferrite ring (diameter 0.8 cm), and the second on a steel core.
When assembling, follow the drawings to avoid mistakes.
How to make a locator from an old player?
Many in the basements and on the mezzanines you can find a lot of interesting gizmos, which, with skillful refinement, can still serve their owner for more than one year. So, from a simple old player, you can construct a locator.
Add power terminals and take care of the search coil. To do this, disassemble the ILV and remove the contact coil. To dismantle the relay plate, you need to clamp it in a vice and use a hammer to knock it out of the coil. This work will take a couple of seconds no more. Now that all the details for the future device have been received, we connect the windings and insert a rod into the core, which we clamp on both sides.
Any improvised object can act as clamps, for example, a plastic tube, which only needs to be sharpened a little, bent so that the part fits in size and performs its working function as a retainer. Let's spend a couple more minutes adjusting the entire device, checking the wiring, connectors, and design reliability. Then solder the wire to the coil, which should then be connected to the amplifier.
The work is ready. As you can see, this is not at all difficult for those who have at least basic knowledge in electronics.
Now you know how to assemble a do-it-yourself locator diagram and a step-by-step instruction will help you do this simple job quickly and efficiently. And it only remains for us to finally wish you good luck and a good day!
When repairing an apartment, it is often necessary to know the places where hidden electrical wiring is carried out. This is necessary for several reasons.
First, when repairing, it is usually necessary to drill holes for mounting various equipment in the walls. At the same time, a drill drill getting into the wiring can, at best, lead to damage to the electrical network, and in the worst case, cause injury to a person.
Secondly, when replacing old hidden wiring, you also need to know where it is laid.
Unfortunately, when repairing is not always available or a private home. And although, in accordance with the rules for installing networks (PUE), cables must be placed strictly horizontally or vertically, often these requirements are not met, and the home power supply circuit is mounted along the shortest paths.
When repairing a failed concealed wiring, it is also desirable to accurately determine the places of breaks without destroying the wall.
There are two main approaches to detecting closed wiring:
- An alternating electric current usually flows through a working network.
- Another principle involves the use of an inductor. If wires or fittings enter its electromagnetic field, it will be distorted, which will be reflected by the indicator of the device.
According to the laws of physics, an electromagnetic field arises around wires with flowing electricity. Most devices for detecting hidden wiring use this property of electric current.
Features of using devices for detecting hidden electrical wiring
To detect hidden wiring, a large number of different devices are available. They have different complexity, capabilities and, of course, different prices. The cost of such devices can vary widely.
Among professional electricians, the E121 hidden wiring indicator is very popular. With this device, you can find the internal electrical network in plaster at a depth of up to 7 cm. The device is easy to use and relatively inexpensive. The price is about 1350 rubles.
MS series devices from China are widely used at home. The advantage of these devices is their low price. The disadvantage is that they react not only to wires, but also to other metals.
Therefore, in order to work effectively with MS instruments, it is necessary to have some experience in order to distinguish signals from copper wires and from other objects made of metal.
The price of the MS 158 detector is 350-900 rubles.
Instead of an amplifier, a multivibrator and an LED can be added to the circuit. When hidden wiring is detected, the first one starts and the light source flashes.
How to find a break in hidden wiring?
Hidden wiring can be a possible culprit for the loss of light in the house. A break in cables can occur, for example, due to the destruction of the old electrical network or damage to it when drilling a wall.
You can detect a break in hidden wiring using the above industrial devices. As a rule, at the place of the break, the device gives the appropriate sign. For example, the sound signal stops.
If a receiver is used as an indicator, then at the place of the break the sound emitted by it will differ from its usual noise.
If there are no devices available, you can try to find a break using a conventional tool like this, almost everyone knows). This method only works if a phase failure has occurred. this article.
To detect a problem area, with the mains turned on, the indicator screwdriver must be slowly led along the hidden wiring and monitor the behavior of the burning light bulb.
Any deviations from the normal glow may indicate the location of the break.
For the case when there was a break in the neutral wire, this method does not work. To check "zero", you need to change the phasing of the wires.
conclusions:
- When repairing and replacing network wires, it is often necessary to find hidden wiring.
- To find such an electrical network, there are a large number of industrial devices, both domestic and foreign.
- To detect a break, you can use both special industrial devices and simple methods, including using an indicator screwdriver.
Demonstration of the device for detecting internal electrical wiring on video
When you plan to hang a picture or a wall clock, how do you choose the right place to hang it? You are probably thinking about how the picture will fit into the interior of the room, on which wall it is better to place it and how. But do you think that not everywhere you can hammer a nail in the wall and drill a hole for the dowel? It's not about what material your walls are made of, as there is a more significant circumstance - this is electrical wiring. In order not to damage the wires immured in the wall, you need to know where they are laid.
There are several ways to find out roughly where the electrical cable runs: you should look into the technical documentation of the apartment and look at the wiring diagram of the electrical network, if there is none, then pay attention to the location of the junction boxes from them wires go to sockets and switches. As a rule, sensible electricians lay the cable at a right angle.
It’s good when you changed the old electrical wiring and are aware of its placement, but what if the previous owner of the house was a mountain self-taught electrician and did not follow the elementary rules for wiring? There are cases when, in order to save money, the wires are bred along the shortest path: from the boxes diagonally and horizontally - in this case, special tools for detecting it cannot be dispensed with.
In stores and radio markets they sell special devices called "Flushed Wiring Detector". They are cheap (low class) and expensive (high class). A low-class device determines the source of electromagnetic radiation - these are live wires and electrical appliances. High-end detectors are more accurate and functional: their work is aimed at detecting wires directly, even those that are without voltage.
For home use, a simple detector that you can make yourself will be enough for us. As you understand, the simple circuit we have assembled refers to budget devices - therefore, we will not succeed in a high-end device. But homemade will help you not to get into trouble when doing construction work and at the moment when you decide to decorate your room with a beautiful picture or wall clock. In order to assemble a concealed wiring detector in haste, we need three non-deficient radio components, which we can easily find.
The main element is the Soviet K561LA7 microcircuit (the detector itself is assembled on it). The microcircuit is sensitive to electromagnetic and static fields emanating from conductors of electrical energy and electronic devices. The microcircuit is protected from an increased electrostatic field by a resistor, which is an intermediate element between the antenna and the IC. The sensitivity of the detector determines the length of the antenna. As an antenna, you can use a single-core copper wire with a length of 5 to 15 centimeters. For stable operation and not at the expense of sensitivity, I chose a length equal to 8 centimeters. There is one caveat: if the antenna length exceeds the threshold of 10 centimeters, there is a risk that the microcircuit will go into self-excitation mode. In this case, the detector may not work correctly. Also, when the electrical cable is buried deep in the plaster, the detector may not make a single sound.
If a homemade detector does not work correctly, it is worth experimenting with a long copper antenna. It can be either less or more than the recommended length. When the detector stops responding to anything except the electrical cable, then you have found the right length (if you have not chosen the correct length, then the detector can respond to a simple touch of a person or any objects).
We figured out the nuances, now we turn to the third element of the circuit - this is a piezoelectric element. A piezoelectric emitter (piezoelectric element) is necessary for the perception by ear of capturing an electromagnetic field, when this happens, the emitter emits a crack. A piezoelectric element or, in a simple way, a “tweeter” can be obtained from a non-working Tetris, Tamagotchi or watch. You can also replace the tweeter with a milliammeter from an old tape recorder. The milliammeter by the deviation of the arrow will show the level of the radiated field. If you decide to use a piezo element and a milliammeter, then the crackling sound emitted will be a little quieter.
The circuit is powered by a voltage of 9 volts, so we need a Krona battery. The assembly of the circuit can be carried out on a printed circuit board or by surface mounting. Hinged mounting for a simple 5-element circuit would be preferable. Take the cardboard, attach the chip with the legs down and pierce holes under each leg with a needle (14 pieces, 7 on each side). After preparing the place for the microcircuit, insert the legs into the holes made and bend them. So we will securely fix the integrated circuit on cardboard and facilitate the work when soldering wires.
In order not to overheat the chip, you should use a low-power soldering iron. A 25-watt soldering iron is usually used for soldering radio components. Let's start assembling the detector according to the scheme given in the article. If you have followed all the above recommendations, then the circuit should work instantly without any adjustment. Now we find a suitable case and embed the circuit in it. Make holes for the tweeter and glue the piezo emitter on the back side. In order for the detector not to work constantly, solder a toggle switch into the power circuit break. Reloading the detector by turning the toggle switch on and off will help you bring the microcircuit out of self-excitation mode.
By tradition, I want to finish the article with a video report on the work done. The video tested the operation of a homemade and factory hidden wiring detector. As it turned out, the made detector more accurately showed the location of the electric cable than a cheap purchased detector.
Having assembled a detector to search for hidden wiring, you should not be afraid of damage to the electrical network of your home, because you can always find an electrical cable. Good luck in mastering simple circuits in radio electronics. If you have any questions, please contact me in the comments - we will figure it out!
About the author:
Greetings, dear readers! My name is Max. I am convinced that almost everything can be done at home with your own hands, I am sure that everyone can do it! In my free time, I like to craft and create something new for myself and my loved ones. You will learn about this and much more in my articles!
During repair work, it is quite common to drill and break walls in which electrical cables pass under the plaster. It is not always possible to use a wiring diagram, but if there is, then there may be little benefit from this - you cannot be sure that the previous owners of the premises or builders did not change the location of the wires without making changes to the circuit.
It turns out wiring detection is an integral part of not only repair work, but also life, because when hammering a nail for a new picture, you can easily damage the cable.
Many unfortunate builders do not think about wiring at all when carrying out repair work, thereby violating safety regulations. The consequences of such negligence can be the most deplorable, so it is advisable to first identify the old wiring in order to protect yourself and your loved ones from unjustified risk.
Here are the main reasons for looking for hidden wiring:
And now - Consequences of a neglectful attitude to safety:
- short circuit;
- improper functioning of the electrical network;
- electric shock;
- fire.
In the worst case, such carelessness will lead to death.
Do-it-yourself hidden wiring search: an overview of the most effective methods
The most effective way, of course, is to contact a specialized company - using professional equipment and many years of experience, it will not only find all the wires, but also provide an accurate diagram of their laying. But such companies are far from being in all cities, and such services are quite expensive, so let's consider how you can find an electrical cable in the wall yourself.
Method one. Set the maximum load on the wiring. Next, take an ordinary compass and, guided by the deviations of the arrow, determine the place where the electrical wire goes.
Method two. You can also mount your own device, consisting of three transistors - one field and two bipolar. The first transistor will be an electric switch, a couple of others will form a multivibration installation. Such a home-made device will capture electromagnetic waves emanating from the wires. If wires are detected, the light on the device will light up, and it will begin to vibrate.
Method three. Another version of a home-made device can be made from a field-effect transistor, batteries and a head TA (phone, that is). To search for wiring, you need to run a transistor along the wall - if the device makes a sound, then the cable is found.
Method four. It is only suitable for major renovations. Note that it is not always effective and is more suitable for rooms with an "old" finish.
Its essence is as follows: it is necessary to remove wallpaper or any other finishing material from the walls. Under it, if you're lucky, you will find a strip that differs in color from the rest of the wall, or represents an unevenness. That's probably where the wiring runs.
Method five. The classic version that was used before the advent of wiring finders. The radio receiver must be tuned to a frequency of 100 kHz and driven along the surface of the wall. In the place where the wire runs, the receiver will emit a characteristic noise resembling interference. In view of the fact that this method was popular among professional electricians, there is no reason to doubt its effectiveness.
Note! During the procedure, pay special attention to sockets and switches - it is near them that cables mostly pass.
Method six. In this case, the electrical wiring is detected using a conventional hearing aid, which makes it possible to perfectly listen to frequencies up to 50 Hz.
Method seven. As an alternative to a radio receiver, you can use a microphone, preferably an electrodynamic coil. It must be connected to any equipment capable of capturing and reproducing the signal. The search procedure itself is no different from the one using the receiver.
Method seven. You can also tie a small magnet to a string and drag it along the wall. It is characteristic that this method is inefficient in panel houses and on ceilings.
Method eight. Do not be upset if none of the methods was successful. You can always resort to a reliable technology for finding electrical wiring, which demonstrates a 100% result. Now we are talking about hidden wiring detectors.
Today, wiring finders are sold in all electrical stores. By conducting such a device along the walls, you can easily identify not only the place where the cables run, but also determine the voltage in them.
Note! Such devices react to both electrical wiring and metal fittings. Therefore, it is recommended to connect a more powerful device to the electrical point in order to enhance the radiation.
Electrical wiring under voltage forms an electromagnetic field. Devices for its detection are aimed at identifying the sources of this field, and the built-in amplifiers allow you to more accurately determine the place where the wire runs. But in order for the seeker to be able to fulfill its functions, some rules should be followed when laying cables.
- Cables should only be laid parallel to architectural lines.
- Horizontal wires should be 1.5 cm away from the overlapping plates.
- If the finishing layer is thicker than 1 cm, then the cables should be laid in the shortest possible way.
- If you do not follow these rules during installation, then it will be quite difficult to detect the wiring.
Such devices can vary in the way they are detected and the complexity of their design. The price range is quite wide - from 100 to 3000 rubles.
Note! When detecting wires, the finder can give both light and sound signals.
Below is a classification of detectors according to the complexity of the design.
- Devices that, according to the principle of operation, remotely resemble metal detectors. They are equipped with a special coil that forms a small electromagnetic field. If an extraneous electrical or iron object gets into such a field, it will immediately change.
- Devices that capture electromagnetic waves emanating from live wires.
- A hybrid of previous devices, which is very expensive, therefore it is used mainly by professionals.
According to the type of design, the seekers are divided into:
- screwdrivers;
- testers.
The design of testers is much more complicated than screwdrivers. Modern models are equipped with laser pointers and are able to detect not only electrical wiring, but also telephone cables. Moreover, testers will allow you to detect even underground wiring. The devices are equipped with a screen backlight, a flashlight and fuses that protect against overvoltage.
An indicator screwdriver is a simpler and cheaper device for detecting wiring, but it is only effective when the wires are at a depth of no more than 2 cm.
This screwdriver can be used in two ways:
- contactless search allows you to determine the location of the wiring;
- contact - makes it possible to measure the voltage.
More modern screwdriver models are equipped with a display showing voltage data; with regards to other devices, they use sound signals for notification.
"Woodpecker" - the most popular wiring finder
In Russia, one of the most popular devices for searching for electrical wiring is the Woodpecker (if officially, then E121). It makes it possible to determine the location of cables under plaster up to 8 cm thick.
Wire finder "Woodpecker"
The technical features of the "Woodpecker" are as follows:
- work from voltage up to 380 Volts;
- weight - 250 grams;
- possibility of contactless search;
- the ability to search for wiring, phase cables, broken electrical appliances and breaks;
- monitoring the operation of the meter and fuses;
- four sensitivity modes.
Let's take a closer look at these modes. Below is distance from the device antenna to the wire for each of them:
- 1 - 0-1.5 mm;
- 2 - 10 mm;
- 3 - 30 mm;
- 4 - 40 mm.
The set with the device "Dyatel" includes a cover, batteries and a technical passport.
Making a hidden wiring detector
If, for one reason or another, buying a finder is not possible, you can always make such a device with your own hands.
Stage one. First you need to choose the case of the future device. For this, for example, a plastic box from a fluorescent lamp may be suitable.
Stage three. Then you need to install 5-volt batteries, then drill a small hole in the case and insert an LED lamp there.
Stage five. It remains only to fix the cover and test the device. It will notify you with a lighted lamp about the detection of hidden electrical wiring.
Note! If the wiring was laid in accordance with all requirements, then it will go vertically or horizontally.
Wire break detection
If one of the hidden cables was damaged, then you can use one of the two existing methods to find it.
Method one. First you need to find out which cable is damaged - zero or phase. Here you will need an indicator screwdriver, which you need to check all the contacts of the failed electric point (switch or socket).
In the switched off switch, only one of the contacts will be energized, but in the switched on both at once. With regards to the outlet, then there will be only one contact in working condition under voltage. In a word, if there is definitely a phase, then you can be sure that the neutral wire has broken.
Note! If the wiring is damaged in some inaccessible place, then it is better to resort to the help of specialists, since it is unlikely that you will be able to find the damaged area on your own.
Method two. If you have full access to all sections of the wiring, a problem area can be identified with an ordinary tester. Here is an example workflow.
- First, the power supply is turned off at the electrical panel.
- Then, two notches must be made on the wire insulation, exposing the metal, one near the outlet from the distribution box, the second two meters from the first.
- Next, using a tester, you should determine the resistance in this section of the wiring. If it is low, then there are definitely no cliffs.
- Similarly, the following sections of the wiring are checked until a section without low resistance is found.
conclusions
As a result, I would like to once again note the importance of determining the location of the electric line before starting repair work. If this is not done, then the consequences of such frivolity can be the most deplorable, perhaps even fatal. Therefore, you need to use one of the described methods (it is desirable, of course, to look for electrical wiring using a sensor) even when an ordinary picture is just hung on the wall.
Device for detecting hidden wiring: signaling device, indicator, hidden wiring detector.
Every time we drill a hole in a wall, there is always the danger of damaging the internal wiring. What should be done to avoid accidentally damaging the wiring? To do this, it is necessary to check its presence on a given section of the wall with a special device, mark the place of the cable and, bypassing it, re-mark the places for drilling.
What if the wiring has a break? How to find the break point?
Device for finding hidden wiring.
Extech DA30 is a non-contact AC sensor.
Operates in the range from 200mA to 1000A, detects the presence of an electromagnetic field created by alternating voltage.
Able to work through shielded wires, cable channels, metal parts of switches and junction boxes.
Manual setting allows you to adjust the sensitivity of the device to detect wires through walls.
It has audible and visual indication. 
The hidden wire finder is supplied with a pocket clip with four LR44 button-type batteries.
Some models of devices for searching for hidden wiring have the ability to determine even when it is without voltage.
Usually operating procedure with such instrument next:
1. Connect the sound generator to the cable
A. For cables with one end connector, connect the red crocodile clip to the wire, and the black clip to the ground of the device case.
b. For wires without an end connector, connect the red clip to one wire and the black clip to the other wire.
V. For cables with modular connectors, insert the RJ11 modules directly into the corresponding cable connector.
2. Set the sound signal switch (Tone) to the “On” position (press the button).
3. On the inductive probe, press the button located on the side of the "On / Off".
4. We bring the insulated tip of the probe to the desired wire in order to detect the signal coming from the sound generator.
5. Turning the sensitivity knob, set the device to the desired level and check the cable for a malfunction.
6. The loudest sound signal comes from the wires connected to the sound generator.
Note: The headphone jack is on the bottom of the probe.
Tester - multimeter to search for hidden wiring
LA-1014 - is a device finder 
hidden wiring (called a cable - a tester) and a multimeter, i.e. universal device containing two in one.
The device allows you to detect hidden wiring without voltage, check the condition of cable lines in telephone and computer and power networks. With the help of LA-1014 it is possible to detect breakage, short circuit and wire overlap. Checking RJ45/RJ11 connectors.
The multimeter allows you to measure the value of direct and alternating voltage, current strength, resistance, continuity of diodes.
The composition of the device to search for hidden wiring.
1. Modular RJ11 connector.
2. Measuring probe with crocodile clip.
3. LED display for checking cable lines in telephone networks.
4. Sound generator low battery LED indicator.
5. Cont button for continuity test mode.
6. Tone button for sound generator (beep switch).
7. Sel button to select signal type.
16. Measuring probe with crocodile clip.
17. Level control knob volume - sensitivity.
18. Power button.
19. Compartment for power supplies.
20. Headphone jack.
Diagram of a device for determining wiring damage
In addition to detecting hidden wiring, the device allows you to detect a broken wire in the power cord of such as video cameras, halogen spotlights, electric irons, drills, meat grinders and similar devices. A cord for connecting 220V, as a rule, its length is 1.5 - 2 meters of a 2-3-core cable with a mains plug at the end. Due to prolonged use, the wire is subjected to mechanical deformation and stress, which can lead to a break, or less commonly, an internal short at any point in the cord. In such cases, we replace the cable, because. Finding a defective wire is quite difficult.
In 3-core cables, it is practically difficult to determine a wire break without test cuts on the cable, especially in a PVC sheath. The circuit of a home-made device will help you quite simply and quickly find the place of a wire break in a 1-core, 2-core, and 3-core cable, without physically damaging the wire. It is built on the CD4069 chip, which contains 6 standard CMOS logic inverters.
On inverters N3 and N4, a pulse generator is assembled, the operating frequency of which is approximately 1000 Hz (audio frequency range), it is determined by the values of the installed resistors R3, R4 and capacitor C1. The amplifier assembled on N1 and N2 amplifies the weak signal coming from the sensor, thereby determining the presence of an alternating field around the 230v network wire. The presence or absence of voltage at output 10 of amplifier N2 can enable or disable the operation of the generator.
When the sensor (probe) is not so close to the wire to which the AC voltage is applied, the output potential at the pin 10 of the inverter N2 remains low. As a result, the open diode D3 shunts the generator circuit. At the same time, the output 6 of the inverter H3 has a low potential - the transistor T1 is in the closed state - LED1 is not lit. When the sensor gets closer to the conductor with a voltage of 230 V AC, 50 Hz, then with each positive half-cycle of the AC voltage, the potential of the output 10 of the N2 inverter becomes high, the oscillator starts at a frequency of about 1 kHz, the red LED (LD1) flashes. (Due to the inertia of the properties of vision, we see the LED burning continuously).
In view of the cyclic operation, the current consumption of the LED decreases, a voltage of 3V DC is sufficient to power the device circuit.
Diagram of a device for detecting hidden wiring.
The circuit is powered by two elements of the AG13 LR44 type, or the like, 1.5v R6 - AA or a rechargeable battery. The circuit draws no more than 3 mA when AC power is detected. For audio-visual indication, you can use a small buzzer or LCD, turn them on instead of Led 1 and resistor R5, but in this case, the current consumption will already be about 7 mA.
With this device, you can quickly detect a faulty lamp in a series-connected Christmas garland, if powered by 230 V AC.
This circuit can be mounted in a small piece of PVC pipe. Before searching for a broken wire with a multimeter or tester, check for voltage, current.
Then apply alternating 230V to the line, connecting the damaged wire to the phase, neutral to the rest of the wires. However, if any of the remaining wires also has a fault, then connect both wires to neutral. To determine a break, it is sometimes enough to apply a phase voltage to the wire under test.
A piece of mounting wire 5 cm long is used as a sensor. To detect a break, turn on the device with switch S1 and slowly move the probe along the damaged wire, starting from the input point and moving towards the end. The LED lights up when there is a field created by AC voltage, when the sensor is located above the break point, the LED goes out.
During testing, it may be necessary to bend the probe to increase sensitivity so that the probe is closer to the cable when moving. Avoid strong electrical fields during testing to avoid false positives.
Technical description of CD4069 chip 125 Kb
Diagram of a simple device. 
The device contains only 7 parts: a field-effect transistor VT1 type KP302, KP303, a voltage divider consisting of two resistors R1 and R2, a pointer indicator from an old PA1 tape recorder, a SA1 power switch, a 1.5v battery. Sensor WA1 is a piece of copper wire several centimeters long. When approaching the WA1 antenna to the mains wire under voltage, it enters the electromagnetic field. The sensor is connected to the gate of the field-effect transistor VT1, as a result, the source-drain resistance increases. The current flowing through the indicator causes the needle to deviate. The greater the current, the stronger the field.
Setting up the device is reduced to the selection of the resistor R1, in the absence of a field, the arrow should not deviate.
If there is no device at hand for detecting a hidden wire, then it can be made in a short time, this requires a wire of any length, preferably a two-wire one, a small-sized transformer, any cassette recorder or player. The transformer will act as a sensor, solder the wire to the transformer, and the other end to the pickup input. The hidden wire must be under mains voltage, i.e. turn on the light switch in the bathroom, etc. and bring the transformer to the intended location of the wiring - an alternating current background should appear in the speaker when approaching the hidden wire.
Broken wire - what to do? Electrical wiring finder.