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Digital technology. Schemes, articles, descriptions

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Digital technology

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Photo background. Transmitting sound with a beam of light

Section Alternative energy sources. Not everyone knows that Alexander Graham Bell did not consider the telephone his most important invention. Indeed, Bell favored another invention that he predicted would revolutionize the means of communication. Bell was obsessed with the idea of ​​transmitting voice with a beam of light! Turning to the Sun as the only reliable source of high-intensity light he had at his disposal, Bell tried to use it as a multi-purpose communications medium. He called his invention the photophone. ... >>

Design Considerations for Common Feedback Amplifiers

Section for radio amateur-designer. Recently, there has been another surge of discussions on a topic that can be conditionally called - for or against negative feedback in amplifiers. Unfortunately, these discussions rarely contain any rational argument, while demonstrating a clear lack of knowledge about the minutiae of working and designing systems with FOS. The situation is complicated by the fact that in most cases, devices are cited as justification for objections to the use of feedback, which in fact turn out to be an example of illiterate or unsuccessful use of it. And then, in the worst traditions of school logic, the conclusion is drawn: feedback is bad! At the same time, examples of the correct use of OOS seem to be becoming increasingly rare, and most likely due to the virtual absence of modern literature on this issue. ... >>

Complementary transistor power amplifier with full arm symmetry for both half-waves of the amplified signal and with a double differential stage at the input

Section Power Amplifiers. The amplifier is completely made on complementary transistors. It works in AB mode. The applied circuit solutions made it possible to reduce non-linear distortions to a minimum. The main feature of the amplifier is the symmetry of the arms for both half-waves of the amplified signal. This made it possible to reduce the non-linear distortion of the amplifier without introducing OOS. Another feature is the output stage circuit, which allows amplifying the signal not only in current, but also in voltage. At the same time, the operating mode of the transistors of the preliminary stage is facilitated, since the required signal amplitude is significantly less than for a conventional output stage. ... >>

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Articles on digital technology

Articles on digital technology; schemes of digital technology; descriptions of digital technology: 54 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 laser can peek through the keyhole 14.09.2021

The ability to "look" into enclosed spaces has long been a science fiction and "superhero" skill. However, researchers from the Computational Imaging Lab at Stanford University, using NLOS (non-line-of-sight imaging) technology as a basis, have ensured that a single beam of laser light penetrating into a closed room, let's say, through a keyhole, will allow you to see all physical objects in this room.

NLOS imaging technology has been a well-known technology for a long time. Based on this method, "smart" cameras have already been created that can look around corners and shoot objects hidden by any obstacles. However, most of the previous implementations of the NLOS-survey technology made it possible to see fairly large objects and flat surfaces, for example, walls in a room. NLOS technology is a very promising technology for a number of areas. Self-driving robotic cars, for example, can use this technology to "look" around corners and recognize potential dangers before a normal camera or human driver can see them.

The technology works as follows - the laser emits a series of short pulses of a certain duration, going through a certain time interval. The laser light is repeatedly reflected from the surfaces of objects, including those hidden by obstacles, some of it comes back and is captured by the camera sensors. Information about how much time has passed between the initial pulse and the registration of the reflected light signal is processed using complex mathematical algorithms that recreate images of objects that do not fall into the direct field of view of the camera. The final images cannot boast of high quality and resolution, but a person can easily recognize objects in these images.

However, the existing implementations of NLOS technology have a number of serious limitations, the quality of its work depends very much on the area and reflectivity of the surface of hidden objects. This, and several other limitations, have made attempting to film from the outside of an enclosed space nearly impossible until recently.

The keyhole method developed at Stanford is so named because it requires only a tiny hole through which a laser beam can illuminate a small spot on the opposite surface. A huge number of photons are repeatedly reflected from the surfaces of walls and objects in the room, but only a small number of photons manage to return back and get to the surface of the avalanche photodetector, which is capable of registering and measuring the arrival time of even single photons.

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