Electroscope with sign indication. Scheme, description

Free technical library

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

Electroscope with sign indication. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Beginner radio amateur

Comments on the article

The well-known school electroscope, with which they demonstrate the phenomena of electrostatics, determines only the presence of an electrostatic charge. And what it is, positive or negative, one can only guess. The device, built by young radio amateurs of the city of Nadvirna, Ivano-Frankivsk region, is deprived of this shortcoming. It not only determines the sign of the charge, but also its approximate value.

A field-effect transistor V1 is connected to the arm of the DC bridge through the capacitor C1 (Fig. 3). When a charged object (ebonite or glass rod, comb, etc.) is brought closer to the antenna W1, a potential difference arises at the terminals of the capacitor C1 and the transistor opens. As a result, the imbalance of the bridge occurs, causing the operation of the polarized relay KR1. The direction of the current in its winding depends on the sign of the charge. Therefore, the relay armature will turn on the right or left group of lamps that display the charge sign.

Electroscope with sign indication
Rice. 1. Schematic diagram of the device

The device is made in a case consisting of two parts. At the top there are light bulbs installed behind the slots in the body, corresponding in configuration to the + and - signs. The slots are closed with tracing paper or milky plexiglass. In the lower part of the case there is a circuit board with a relay and two 3336L batteries (Fig. 2).

Electroscope with sign indication
Rice. 2. Device design

With a variable resistor R5, the sensitivity of the device is the same for both signs of charges.

The device uses a polarized relay RP-5 (passport RS4.522.005). Instead of D814A zener diodes, you can use D808, D809, KS133A, KS139A, KS147A, KS1S8A.

If only one lamp is used to display the charge sign, one 3336L battery will be enough to power the device.

The antenna is a piece of wire 300 mm long, Ø 3 mm. The socket for its connection - from any school measuring device.

Author: Ya.Buchko

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

Glass air conditioner 30.06.2016

Inventors in Bangladesh figured out how to use glass containers as air conditioners that do not consume electricity. The scientific justification for the device called Eco-Cooler is quite simple. When passing through a funnel or other narrowed space like the neck of a bottle, the air is compressed and cooled by five degrees. We observe this effect when we blow on a burnt finger - the air, passing through lips compressed into a tube, becomes cool, despite the body temperature of 36,6 ° C.

In addition to the obvious benefits in regions experiencing energy difficulties, Eco-Cooler helps to cope with the problem of excess plastic bottles. According to some estimates, about 50 billion of these bottles are used annually in the world, but only 20% of them are recycled.

In Bangladesh, where summer temperatures reach 45°C, more than 25 of these air conditioners are already in use, with blueprints being offered to the public free of charge thanks to the support of Grameen Intel, a joint venture between Nobel Peace Prize winner and microfinance pioneer Muhammad Yunus, the Grameen Foundation. and the American company Intel.

Other interesting news:

▪ A device that mimics the brain

▪ Germany refuses cars with internal combustion engines

▪ Milk began to drink in the Urals

▪ A supercapacitor is 5 times thinner than a sheet of paper

▪ Electric liner for short flights

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Fundamentals of safe life (OBZhD). Article selection

▪ article Trade unions - the school of communism. Popular expression

▪ article What is a laser? Detailed answer

▪ article wild apple tree. Legends, cultivation, methods of application

▪ article Security system of remote objects with digital indication. Encyclopedia of radio electronics and electrical engineering

▪ article A glass of milk. Focus Secret

Leave your comment on this article:

All languages of this page

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