Mineral electrical insulating materials. Scheme, description

Free technical library

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

Mineral electrical insulating materials. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Electricity for beginners

Comments on the article

Mineral electrical insulating materials include rocks: mica, marble, slate, soapstone and basalt. This group also includes materials obtained from Portland cement and asbestos (asbestos cement and asboplast). This whole group of inorganic dielectrics is characterized by high resistance to electric arc and has sufficiently high mechanical characteristics. Mineral dielectrics (except mica and basalt) can be machined, except for threading.

Electrical insulating products from marble, slate and soapstone are obtained in the form of boards for panels and electrical insulating bases for knife switches and low voltage switches. Exactly the same products from fused basalt can only be obtained by casting into molds. In order for basalt products to have the necessary mechanical and electrical characteristics, they are subjected to heat treatment in order to form a crystalline phase in the material.

Electrical insulating products made of asbestos cement and asboplast are boards, bases, partitions and arc chutes. For the manufacture of such products, a mixture consisting of Portland cement and asbestos fiber is used.

Asboplast products are obtained by cold pressing from a mass to which 1-5% of a plastic substance (kaolin or molding clay) is added. This achieves a greater fluidity of the initial pressed mass, which makes it possible to obtain electrical insulating products of a complex profile from asboplast.

The main disadvantage of many mineral dielectrics (with the exception of mica) is the low level of their electrical characteristics, caused by a large number of pores and the presence of iron oxides. This phenomenon allows the use of mineral dielectrics only in low voltage devices.

In most cases, all mineral dielectrics, except for mica and basalt, are impregnated with paraffin, bitumen, styrene, bakelite resins, etc. before use. The greatest effect is achieved by impregnating already machined mineral dielectrics (panels, partitions, chambers, etc.).

Marble and products from it do not tolerate sudden changes in temperature and crack. Slate, basalt, soapstone, mica and asbestos cement are more resistant to sudden changes in temperature.

Author: Smirnova L.N.

See other articles Section Electricity for beginners.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Air trap for insects 01.05.2024

Agriculture is one of the key sectors of the economy, and pest control is an integral part of this process. A team of scientists from the Indian Council of Agricultural Research-Central Potato Research Institute (ICAR-CPRI), Shimla, has come up with an innovative solution to this problem - a wind-powered insect air trap. This device addresses the shortcomings of traditional pest control methods by providing real-time insect population data. The trap is powered entirely by wind energy, making it an environmentally friendly solution that requires no power. Its unique design allows monitoring of both harmful and beneficial insects, providing a complete overview of the population in any agricultural area. “By assessing target pests at the right time, we can take necessary measures to control both pests and diseases,” says Kapil ... >>

The threat of space debris to the Earth's magnetic field 01.05.2024

More and more often we hear about an increase in the amount of space debris surrounding our planet. However, it is not only active satellites and spacecraft that contribute to this problem, but also debris from old missions. The growing number of satellites launched by companies like SpaceX creates not only opportunities for the development of the Internet, but also serious threats to space security. Experts are now turning their attention to the potential implications for the Earth's magnetic field. Dr. Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics emphasizes that companies are rapidly deploying satellite constellations, and the number of satellites could grow to 100 in the next decade. The rapid development of these cosmic armadas of satellites can lead to contamination of the Earth's plasma environment with dangerous debris and a threat to the stability of the magnetosphere. Metal debris from used rockets can disrupt the ionosphere and magnetosphere. Both of these systems play a key role in protecting the atmosphere and maintaining ... >>

Solidification of bulk substances 30.04.2024

There are quite a few mysteries in the world of science, and one of them is the strange behavior of bulk materials. They may behave like a solid but suddenly turn into a flowing liquid. This phenomenon has attracted the attention of many researchers, and we may finally be getting closer to solving this mystery. Imagine sand in an hourglass. It usually flows freely, but in some cases its particles begin to get stuck, turning from a liquid to a solid. This transition has important implications for many areas, from drug production to construction. Researchers from the USA have attempted to describe this phenomenon and come closer to understanding it. In the study, the scientists conducted simulations in the laboratory using data from bags of polystyrene beads. They found that the vibrations within these sets had specific frequencies, meaning that only certain types of vibrations could travel through the material. Received ... >>

Random news from the Archive

Robots can read your mind 06.07.2018

With the help of a new robot control system, a human can prevent a machine error and redirect it using brainwaves and simple gestures. People who control robots in factories, homes or hospitals will be able to use the installation.

MIT AI specialist Daniela Rus and her colleagues tested the system with seven volunteers. Each user controlled a robot that moved the drill to one of three possible targets, indicated by an LED light on the model aircraft's fuselage. Whenever the robot started moving towards the wrong target, the error signal from the user would stop it. And when the user turned their wrist left or right to redirect the robot, the machine moved towards the corresponding target. Out of more than 1000 trials, the robot initially selected the correct target about 70% of the time, and after human intervention, more than 97% of the time.

The team plans to create a system version that recognizes a wider range of human movements. In this way, "you can show how the robot should move, and your movement can be interpreted more quickly," says study co-author Joseph Del Preto, also an artificial intelligence specialist at the Massachusetts Institute of Technology.

Commands through the brain and muscle activity can work particularly well in noisy or poorly lit environments, such as factories or outdoor venues. In such areas, other means to manually control robots, such as visual cues or verbal instructions, may not work, says Alexander Barachant, a researcher at New York-based startup CTRL-Labs. This method can also be used by people who cannot speak or move, such as patients with amyotrophic lateral sclerosis.

Moreover, the system is able to correct robot errors almost instantly. The potentials associated with errors in the brain are noticeable several hundred milliseconds after a person notices an error, and muscle electrical signals can be detected even before the actual movement, Barachant explained. This feature can be useful in situations where responsiveness is very important for the safety of the robot and other people - both for unmanned vehicles and production machines.

For this system to be widely used, equipment that tracks users' brain activity needs to be more widely available than it is now. This mind control device can cost thousands of dollars, and electrode caps are hardly the most comfortable headgear. But if researchers could measure the brain signals with cheaper and more comfortable headsets, the system could provide a relatively quick and easy way for regular users to get the robot to fulfill their requirements.

Other interesting news:

▪ NEC's thinnest 15,6" ultrabook

▪ Smart people think slower

▪ food from thin air

▪ Gigabit Powerline - a chip for home networks through electrical wiring

▪ Hearing genes in plants

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Tools and mechanisms for agriculture. Article selection

▪ article Synthetic fibers. History of invention and production

▪ article Why did King Mithridates want to, but could not, commit suicide? Detailed answer

▪ article Small-fruited horse fennel. Legends, cultivation, methods of application

▪ article Soft start and stop of the electric motor. Encyclopedia of radio electronics and electrical engineering

▪ article Focus shifter. Focus Secret

Leave your comment on this article:

All languages of this page

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