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Personal safety. Schemes, articles, descriptions

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Personal safety

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Transistor power amplifier of the radio station of the first category

Section RF power amplifiers. The widespread opinion that it is impossible or very difficult to build a broadband transistorized power amplifier for a first category radio station repels most shortwavers from this undertaking. The task set by the author was to show the possibility of building, describing the circuit and setting methods for a highly reliable transistor power amplifier that provides an output power of at least 150 W with the output transistors in various unfavorable conditions using the example of an operating and in operation linear power amplifier. conditions, such as: operation for an unmatched load, cable breakage or short circuit in the antenna-feeder system, switching errors of band filters, overheating of the amplifier transistor cooling radiator, and more ... >>

Fast charger for Ni-Cd and Ni-MH batteries

Section Chargers, batteries, galvanic cells. The device described in the article is designed for accelerated charging of Ni-Cd and Ni-MH batteries with an exponentially decreasing current. Its advantages include the ability to select the charging time in the range from 45 minutes to 3 hours, ease of manufacture and adjustment, no heating of the batteries at the end of charging, the ability to visually control the charging process, automatic recovery of the process when the power is turned off and then turned on, ease of use. The device can be used as a stand for measuring the charging and discharging characteristics of batteries ... >>

Power amplifiers. Part two

Section Transistor power amplifiers. We continue. Next up is class AB. Actually, already from the name it is clear that this scheme for constructing the output stage is obtained by crossing an octopus with a hanger. That is, class A and class B. From the first we take a non-zero quiescent current I0>0. Thus, the bias voltage at the bases of the transistors is present ... >>

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Articles on personal safety

Articles on personal security; schemes of devices for personal safety; descriptions of devices for personal safety: 7 articles



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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

LCD TV with over 68 billion colors 13.06.2005

According to The Korea Times, LG-Philips will unveil a prototype 42-inch high-resolution LCD panel displaying 68,7 billion colors at the Society for Information Display (SID) exhibition in Boston on May 27, 2005.

The new development was created using 12-bit LCD System technology and reproduces 4 times more color than current panels. Conventional LCD panels now display about 16,7 million colors.

In addition, the new TV eliminated the effect of "blurring" when showing a moving object.

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