Television cable or coherent has a braid, unlike simple wiring. This is needed for shielding. With an increase in the frequency of the current, the depth of its penetration into the core decreases. And at some point the flow becomes purely superficial. Part of the power begins to radiate from the wiring in the wall. All antennas work on this principle. The custom lived in the wall glows in the low frequency range, users figured out how to find electrical wiring in the wall for a similar feature.
Radiation difficulties of the wiring
In the west, the wiring in the wall fits into the protective channels of the metal. Then the screen is grounded. If this is not done - leave it hanging in the air - half of the radiation will be reflected inwards. This is evidenced by the science with the complex name "Electrodynamics of the propagation of radio waves."The veins in the wall go along the floor, and the sockets stand in the corners. To be away from man.
A frequency of 50 Hz radiation causes drowsiness, headaches and a constant feeling of fatigue. It is customary to keep silent about such a property. As early as 1963, the works were published, which clearly showed that with excessive field strength( 650 kV / m) in the 50 Hz range, laboratory mice died within a few hours. For comparison, SanPiN allowed for residential premises a value of 0.5 kV / m( http: //ecolab21.ru/ izmerenie_promyshlennoy_chastoty_50_gc).Analytical centers were created to measure the parameter and for electrical wiring in the wall. For a fee, of course.
The irritation of living cells by a field is called electrostimulation. Physiology is constantly looking, together with medicine, for ways to influence humans and animals( not with the help of electrical wiring in the wall).And the most annoying effect of the current at frequencies from 50 to 100 Hz. With increasing frequency, the effect decreases. Radiation increases the conductivity of the central nervous system. Radiation with a frequency of 50 Hz causes a disturbance of circadian rhythms, and upon prolonged exposure with a force of 5 kV / m provokes neuroses and irritation.
But wondering how to find electrical wiring in a concrete wall. Two methods are used:
- Tracking of the mentioned 50 Hz frequency from the electrical wiring in the wall by the detector. A super long range radio would suit. Broadcasting in it is not conducted due to the fact that a low frequency will not allow to encode useful information. But we will try to construct a similar one with our own hands to search for electrical wiring in the wall. It is clear that a quarter-wave antenna is easy to make. The length would go about hundreds of kilometers. Experts recommend using a piece of copper wire of sufficient thickness to search for electrical wiring in the wall. It should be straight, so taking the antenna from the radio is absolutely not recommended. The sensitivity of the device to search is low, and you have to do it yourself. A simple household radio is not suitable, as it contains devices and filters that cut off the desired range. The low frequencies pass through the water, and the sonar could fit in as a detector.
- The second method is often used to evaluate the paths of reinforcement in the wall. Will fit and to search for electrical wiring in the wall. The equipment is expensive, radiates and catches the signal reflected from the metal. In terms of the principle of action, a full-featured locator is obtained. Actually, this is how equipment is called. The difficulty is that it can cost from 100.000 rubles and above.
It is necessary to search the wall for electrical wiring either to assemble the simplest detector with your own hands, or to order it from China for about 4,000 rubles. Fortunately, there is plenty of goods on the market. The average "metal detector" to search for, reacts to non-ferrous and ferrous alloys, the distance varies around 10 cm. This is enough for most people who want to make repairs with their own hands.
Home-made designs for determining the location of electrical wiring in the wall
On the Internet, it is proposed to assemble the simplest devices to search for electrical wiring in the wall. The first of them operates on the basis of the K561 LA7 chip. We believe that any similar sense will be suitable for search. Through a resistor of about 1 megohm with electric wires, the signal arrives at both inputs of the NAND logic function. When signs of reception appear, internal amplifiers form a viable "zero".We submit it to another IC-NES chip, and connect one to a piezo call. Shop Chip & Dip for this purpose recommends using ZP-3.
We believe that this is not the only option, but we would like to add that there are several chip families in digital technology. Need to take a device where the threshold is lower. But the sensitivity of the device will greatly increase. For example, there are sets of logics:
- K651 LA7 belongs to the CMOS family( complementary transistors such as metal oxide semiconductor).We understand from the specification that the input voltage of a high level should be at least 7.2 V. At a field strength of 500 V / m, this requires a wire cut not shorter than 1.5 centimeters. The calculation is approximate, and around interference is possible. The level of 0.5 kV / m is considered the maximum allowable, as we mentioned earlier.
- The TTL series( transistor logic) has a logic level of a unit of the order of 2–2.5 V depending on the specific series. What makes this type of device more acceptable for building a sensitive detector. For example, the KR1531 LA4 microcircuit contains three full-featured AND-NOT elements. The threshold is about 2.7 V, which is three times lower than in the previous version.
- The ECL series( emitter-coupled logic) has inverted levels and was considered promising. Minus 1.7 V is needed for a logical zero. But now remember that the voltage is variable, since the field is electromagnetic. There are no difficulties here. It is necessary to find, by analogy, a microcircuit from the NAND elements, power it correctly, turn on the wire-antenna from the first end, from the second end - the bell on any element recognizing negative voltage. For example, ZP-3 but with a different polarity.
I wanted to add about the principle of operation of such a detector:
- A small signal is caught by a bare wire. The length should be further from the quarter-wave WiFi antennas( 2.4 or 5 Hz), so that there is less interference.
- Through a resistance that limits false alarms from interference, the voltage arrives at the NAND element.
- Inside, there are nonlinear amplifying elements like transistors, which bring a small signal to a stable zero and one in the local digital logic system.
- Then, through the other element, the signal is put on the indicator. For example, the LED from the logic that the chip. For example, the Chip & Dip store suggests using a sliding ammeter scale for this purpose. Anything that can be obtained and controlled after being included in the device will do. And the method will be visual or auditory, is not so important.
Wiring in the wall does not emit until there is no consumption. In the free state, the energy meter does not work: a load is needed. If the wiring on the ceiling, turn on the chandelier, if on the wall - turn on the electric kettle. In this case, energy begins to flow through the core; a part of it is radiated into free space.
Metal Detectors for Detecting Wiring in an
Wall Unlike the process described above, metal detectors emit and then catch the reflected signal. The minus that often comes across fittings. It is made of metal and has, albeit low, but conductivity. Therefore, will serve as a source of re-reflected signal. And at a frequency of 50 Hz, a similar device probably will not react.
Inside is a constant frequency generator, and internal filters are tuned to it. As transceiver antenna. Plus, no extra steps are required. Original devices still need to adjust. If there is free time, but there is no money, then it is better to make a detector for detecting electrical wiring in the wall personally.
Metal detector is a miniature receiver at the same time. The buzzer serves as a signaling device, but does not prohibit the use of anything else in return. Having the similar device on hands, it is easy to apply with chalk a wall trajectory of laying an electric wire. The old one is hollowed out or cut out by a wall chaser. In its place fit new in accordance with the requirements of the electrical project on the premises. We have already said that it is necessary to shield this with metal channels.
Grounding, accepted everywhere, with the exception of Russia, serves to reduce the level of electromagnetic interference in the first place. And already in the second it protects against accidental breakdown of the insulation. Do not neglect the organization of grounding in your own apartment. There are specific moments. For example, in the break of the switch you need to connect the current phase. To search for zero you need a device. In the hardware store we buy a probe indicator in the form of a screwdriver, showing the location. By accepted standards, phase, zero, and earth are different in color. More precisely, you need to look at the place.
Many people wonder how to ring the wiring. Easier to start from the shield. There are traffic jams. They are unscrewed and with one end go into the apartment. Or there are automatic machines. Usually there are two security devices, and the consumers in the premises should call the devices. As for the location of the fault, then a special tool is used. Similar to a ringing cable underground, but smaller in size.
It also helps to find the probability of a short circuit in a hidden wiring. In contrast to detectors and metal detectors, this is called a tracker. It will also show the presence of tension in the core in a contactless manner. But the device costs already from 20.000 rubles. And to buy it to save three meters of electric wire is impractical. It is rather a reliable assistant professional builders. And it is cheaper than an armature locator( it allows controllers to make a decision, for example, on the compliance of the object to be handed over to the project documentation).
We hope that the problem is solved. We add that if a piece of wiring gets into the disk drive, the consequences will be unpredictable. If possible, more precisely, draw the path of the core. Sometimes it is useful to make a surface gouge to understand how far from the surface to the insulation of electrical wiring.