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Note to the student. Schemes, articles, descriptions

Free library / Schemes of radio-electronic and electrical devices

Note to the student

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Mains supply for low-voltage radio equipment, 3 volts 0,2 amperes

Section Power supplies. Modern portable and pocket radios, especially imported ones, as a rule, are powered by two batteries or accumulators and can be powered under stationary conditions from any source with a stabilized voltage of 3 V and a permissible current of up to 0,2 A. The same voltage is also necessary for powering electronic games such as OH WAIT and many other devices. The necessary power supply, if you try, can be found in commercial stores, but imported and at an unreasonably high price, and the domestic industry produces few such power supplies. In addition, they usually do not have output voltage stabilization, which leads to listening to the network background. ... >>

Economical infrared generator

Section Infrared technology. The emitter of the IR sensor, which responds to beam interruption, is often located 10...20 m or more from the photodetector. Its placement, which meets the requirements of security equipment (hidden position, protection from bad weather, intentional damage, blocking, etc.), will be significantly simplified if it is made in the form of an autonomously functioning unit. The most important parameter of such a radiator will obviously be its ability to make the most efficient use of the energy reserves of the power source built into it. A schematic diagram of an energy-efficient IR generator that generates fairly powerful IR pulses is shown in Fig. 32 ... >>

Volume, balance and tone control on the TDA1524A chip

Section Tone and volume controls. This circuit is implemented on a Philips TDA1524A integrated circuit (A1524A is an analogue of the RFT company). The microcircuit is a two-channel (stereo) volume control, balance and timbre of low and high frequencies. There is also loudnes (frequency compensation). Variable resistors can be used any, because. volume, balance and timbre in this microcircuit is carried out electronically. Trimmer resistors R7 and R8 regulate the gain of the output signal, the button S1, which turns on the frequency compensation of the volume control (off in the diagram), must be latched. For those who want to constantly use frequency compensation without the possibility of turning it off, elements S1 and R9 can be excluded from the circuit. During operation, the microcircuit heats up. Glue to it (for example, with Moment glue) a small U-shaped aluminum radiator. This will increase the reliability and service life of the chip. ... >>

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Articles for the student

Articles for the student; schemes for the student; descriptions for the student: 14 articles



Latest news of science and technology, new electronics:

The speech of sperm whales is similar to that of humans 18.05.2024

In the world of the ocean, where the mysterious and unknown coexists with the studied, sperm whales, with their huge brains, are of particular interest to science. Researchers, working with a huge array of audio recordings collected during the Dominica Sperm Whale Project (DSWP) - more than 8000 recordings, seek to unravel the secrets of their communication and understand the structure and complexity of the language of these mysterious creatures. By studying in detail the recordings of 60 sperm whales in the eastern Caribbean, scientists have revealed surprising features of their communication, revealing the complexity of their language. "Our observations indicate that these whales have a highly developed combinatorial communication system, including rubato and ornaments, which indicates their ability to quickly adapt and vary during communication. Despite significant differences in evolution, sperm whales have elements in their communication that are characteristic of human communication," says Shane Gero, a biologist at Carleton University and director of the CETI project. Issl ... >>

Electron spin for quantum information transfer 18.05.2024

The transfer of quantum information remains one of the key tasks of modern science. Recent advances in the use of electron spin to expand the capabilities of information transfer in quantum systems have become very important. Researchers at Lawrence Berkeley National Laboratory are pushing the frontiers of quantum information science by experimenting with the possibilities of electron spin. Electron spin, a natural quantum bit, is a potentially powerful means for storing and transmitting information in quantum systems. Magnon wave packets, collective excitations of electron spin, have revealed their potential to transmit quantum information over significant distances. The work of Berkeley Lab researchers has revolutionized the way such excitations propagate in antiferromagnets, opening up new prospects for quantum technologies. Using pairs of laser pulses, scientists disrupted antiferromagnetic order in one place and simultaneously studied it in another, creating ... >>

Sound-absorbing silk 17.05.2024

In a world where noise is becoming increasingly intrusive, the emergence of innovative materials that can reduce its impact is of great interest. MIT researchers have unveiled a new sound-absorbing silk fabric that promises to revolutionize quiet spaces. The Massachusetts Institute of Technology (MIT) has made significant breakthroughs in the field of sound absorption. Researchers have developed a special silk fabric that can effectively absorb sound and create cozy, quiet environments. The fabric, thinner than a human hair, contains a unique vibrating fiber that is activated when voltage is applied to it. This feature allows the fabric to be used to suppress sound waves in two different ways. The first method uses fabric vibrations to generate sound waves that cover and cancel out unwanted noise, similar to noise-canceling headphones. This p ... >>

Random news from the Archive

The inhabitants of Pompeii sorted garbage for reuse 29.04.2020

Archaeologists have found that the inhabitants of Pompeii were engaged in sorting garbage, and also exchanged construction waste for reuse.

An analysis of soil samples that covered the debris found within Pompeii and outside the city showed that organic and construction waste was stored separately. That is, the ancient Romans sorted garbage.

"The walls of buildings in the city of Pompeii were also made of garbage - ancient Roman builders used materials such as crushed tiles, fragments of ceramics, fragments of plaster, and so on. Smooth and plastered walls are actually made of garbage. But something else is interesting .

An analysis of the soil, particles of which were preserved in this garbage, showed that it was carefully sorted before being reused. Obviously, the inhabitants of Pompeii and the surrounding area collected, sorted and sold garbage for reuse," says Allison Emmerson, professor at Tulane University of Louisiana (USA), author of the study.

It was previously believed that Pompeii's dumps were formed from garbage that was cleaned out of the city after a devastating earthquake in 62 AD, which killed 2 of the city's 12 inhabitants.) But now it has become clear to scientists that the origin of the dumps is different.

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