Probe without battery. Scheme, description

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

Probe without battery. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Beginner radio amateur

Comments on the article

Probes for "ringing" electrical circuits, checking the integrity of the windings of various electric motors, starters, electromagnetic relays, filaments of incandescent lamps, pn junctions of diodes and powerful transistors contain batteries of galvanic cells. However, batteries deplete relatively quickly and have to be replaced.

At the same time, it is possible to make probes that work... without a battery, which means that they can last "forever". A diagram of one of the designs of such a probe is shown in fig. 1. It consists of indicator light 1 (LED), solenoid winding 2, permanent magnet 3 located inside the solenoid, spring 4 and spring attachment 5.

Probe without battery

By connecting the probes X1, X2, for example, crocodile clips, to the circuit under test, pull the magnet out of the solenoid, and then release it. The stretched spring draws the magnet in, giving it a damped reciprocating motion. In the solenoid winding, an EMF of self-induction occurs, which is proportional to the rate of change of the magnetic flux: E = Nx Δph / Δt., Where E is the EMF of self-induction; N is the number of turns of the winding; Ф - magnetic flux; t - time.

If the circuit is OK, the HL1 LED flashes. When checking the diode, LED flashes should be observed only with one polarity of connecting the probes to the diode terminals. If flashes are observed with both connection polarities, then the diode is faulty. If there are no flashes, the diode is broken. The pn junctions of transistors are checked in the same way. Since the collector of a power transistor is usually connected to the case, it is not difficult to determine the pinout of the transistor.

Any LED will do, with a constant forward current of up to 20 mA. As a solenoid, the authors used the coil of a polarized relay RP-4, connecting its two windings in series. Inside the coil there is a magnet 40 mm long and 3x3 mm in cross section. Of course, other options are also possible.

The task of designing a "batteryless" probe will be simplified if you use the electric motor of a failed cassette recorder. Together with the LED, the electric motor is placed, for example, in a polyethylene shampoo bottle (Fig. 2). The electric motor is fixed with studs, to which wires are soldered in insulation and with crocodile clips at the ends. The transparent body of the bottle makes it possible to observe LED flashes even with peripheral vision.

Probe without battery

To "start" the probe, turn the motor shaft a few revolutions with your thumb and forefinger.

Author: S.Levchenko, V.Vedutov, St. Petersburg

See other articles Section Beginner radio amateur.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Alcohol content of warm beer 07.05.2024

Beer, as one of the most common alcoholic drinks, has its own unique taste, which can change depending on the temperature of consumption. A new study by an international team of scientists has found that beer temperature has a significant impact on the perception of alcoholic taste. The study, led by materials scientist Lei Jiang, found that at different temperatures, ethanol and water molecules form different types of clusters, which affects the perception of alcoholic taste. At low temperatures, more pyramid-like clusters form, which reduces the pungency of the "ethanol" taste and makes the drink taste less alcoholic. On the contrary, as the temperature increases, the clusters become more chain-like, resulting in a more pronounced alcoholic taste. This explains why the taste of some alcoholic drinks, such as baijiu, can change depending on temperature. The data obtained opens up new prospects for beverage manufacturers, ... >>

Major risk factor for gambling addiction 07.05.2024

Computer games are becoming an increasingly popular form of entertainment among teenagers, but the associated risk of gaming addiction remains a significant problem. American scientists conducted a study to determine the main factors contributing to this addiction and offer recommendations for its prevention. Over the course of six years, 385 teenagers were followed to find out what factors may predispose them to gambling addiction. The results showed that 90% of study participants were not at risk of addiction, while 10% became gambling addicts. It turned out that the key factor in the onset of gambling addiction is a low level of prosocial behavior. Teenagers with a low level of prosocial behavior do not show interest in the help and support of others, which can lead to a loss of contact with the real world and a deepening dependence on virtual reality offered by computer games. Based on these results, scientists ... >>

Traffic noise delays the growth of chicks 06.05.2024

The sounds that surround us in modern cities are becoming increasingly piercing. However, few people think about how this noise affects the animal world, especially such delicate creatures as chicks that have not yet hatched from their eggs. Recent research is shedding light on this issue, indicating serious consequences for their development and survival. Scientists have found that exposure of zebra diamondback chicks to traffic noise can cause serious disruption to their development. Experiments have shown that noise pollution can significantly delay their hatching, and those chicks that do emerge face a number of health-promoting problems. The researchers also found that the negative effects of noise pollution extend into the adult birds. Reduced chances of reproduction and decreased fertility indicate the long-term effects that traffic noise has on wildlife. The study results highlight the need ... >>

Random news from the Archive

Hydrogen-electric aircraft Odonata 17.11.2023

German manufacturer Odonata has unveiled an innovative hydrogen-electric aircraft that will soon be used for short-haul passenger transport. This air transport has a vertical take-off and landing system, which makes it possible to do without large runways and specialized infrastructure.

Odonata represents the promise of a new era in air travel, combining hydrogen energy and electric mobility. Despite technical and safety challenges, the new aircraft reflects the desire for a clean and efficient aviation future.

Engineers emphasize that this is not another electric aircraft (eVOLT), but an aircraft operating on a hydrogen-electric propulsion system. The hydrogen fuel generates electricity by charging the batteries, while the six propellers that control the aircraft are powered by built-in batteries without interacting directly with the hydrogen. When fully loaded, the aircraft can cover a distance of 1000 km.

Compared to competitors in the eVOLT segment, which have a range of 100-300 km, the new hydrogen aircraft, which does not yet have an official name, promises to meet the needs of short flights in Europe or the United States. It's important to note that comparisons with traditional electric aircraft are not entirely appropriate here, since eVOLTs are powered by a battery charged from the grid, unlike a hydrogen aircraft.

One of the advantages of the new product is that there is no need for a complex infrastructure for refueling, since hydrogen is easy to transport and its refueling takes much less time compared to its electric counterparts. However, there is a problem with the explosiveness of hydrogen, which the developers intend to solve.

Until 2030, it is planned to produce a production model capable of transporting eight passengers, a pilot and cargo weighing up to 800 kg over a considerable distance without harmful emissions into the atmosphere.

Other interesting news:

▪ Creation of new plants without DNA insertion

▪ Robotic materials with the properties of living beings

▪ Electronics will evaluate the level of sweetness of food and drinks

▪ Sugar is bad for the brain

▪ Artificial sun against viruses

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Factory technology at home. Article selection

▪ article Hence the anger and tears. Popular expression

▪ article Where and when was a tsunami over 500 meters high recorded? Detailed answer

▪ article Tourist amphibious boat Amfa. Personal transport

▪ article Lighter for gas. Encyclopedia of radio electronics and electrical engineering

▪ article Replacing the SD4842P67K65 chip with FSDH321 in the S-12-12 power supply. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews