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Antenna amplifiers. Schemes, articles, descriptions

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Antenna amplifiers

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Solar Power Plants

Section Alternative energy sources. The use of solar energy today is reduced mainly to the production of low-grade solar heat using the simplest flat-plate solar collectors. For example, in the United States in 1990, out of 3,6 million GJ of energy produced from solar radiation, 3,5 million GJ is low-grade heat used for hot water supply, heating water in swimming pools and, to a lesser extent, for heating. About 800 solar collectors have been installed in Israel, under a law requiring every home to have a solar water heater, which generates about 000 million GJ of energy and provides 15% of the population with hot water ... >>

Device for detecting moving metal objects

Section for radio amateur-designer. The principle of operation of the described device is based on the effect of eddy currents arising in a metal object on the quality factor of the coil that creates a magnetic field. It can be used to detect unwanted metal objects in a moving mass of any raw material or finished product, to count metal parts or the number of vehicles passing through a checkpoint, etc. ... >>

Starting a three-phase motor

Section Electric motors. Some radio amateurs use a drive from a three-phase motor with capacitor switching for their designs. For normal operation, which excludes a strong overload of the winding connected through the capacitor, it is necessary to turn off the starting capacitor after the engine is accelerated, leaving the working capacitor on. A simple device is proposed that allows you to perform the operation of switching off the starting capacitor automatically (see figure). Normally closed relay contact after engine acceleration, when the voltage on the capacitor plates increases, opens ... >>

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Articles on antenna amplifiers

Articles on antenna amplifiers; antenna amplifier circuits; descriptions of antenna amplifiers: 31 articles



All articles on antennas



Latest news of science and technology, new electronics:

Blinking of the magician and his audience 19.05.2024

Magic and illusions have always captured the attention of the public, but what happens behind the scenes of the magician and in the brains of his audience? Scientists from the UK decided to solve this mystery by conducting a new study involving ten illusionists of varying experience. Illusionists, some of whom had been practicing magic for more than half a century, others for only six months, were invited to demonstrate the same trick - the popular coin trick. Recordings of their performances during training and on stage showed that each of them began to blink significantly more often at the moment of performing the trick. The study's findings indicate that magicians' blink rate may be related to unconscious aspects of their performance. At the same time, as scientists have found, spectators also begin to blink more often, following the movements of the illusionist. This observation supports the idea that magicians may be catalysts for blinking in audiences. Additional research has shown that magicians blink more often during ... >>

Ultrasonic coffee machine 19.05.2024

Iced coffee has become an integral part of coffee culture in recent years. Therefore, engineers from the University of New South Wales decided to improve its preparation. They have developed an ultrasonic coffee machine that reduces the cold brew time for ground coffee beans from 12-24 hours to significantly less time. Iced coffee, or "Cold brew", is popular due to its smoothness, low acidity and low bitterness. It is prepared by steeping ground coffee in cold water for a long time. Unlike traditional hot brewing, which often imparts bitterness to coffee, cold brewing extracts more delicate and complex flavors from the coffee beans. The innovative system, presented by a team of engineers, introduces ultrasonic technology into the coffee preparation process. The system uses ultrasonic waves to speed up the process of extracting oils, flavor and aroma from ground coffee. This allows you to significantly reduce the time ... >>

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 ... >>

Random news from the Archive

New record for longest non-stop flight 18.11.2019

In civil aviation, a new record for the duration of a non-stop flight by a commercial airliner has appeared - it, like the previous achievement, was set by Qantas.

The crew of the Boeing 787 Dreamliner spent 19 hours and 19 minutes in the sky, covering about 17 kilometers during this time on the way from British London to Australian Sydney. Flight QF 800 was flying from Heathrow Airport to the international airport of Australia's largest and oldest city.

The flight took place over the territories of Great Britain, the Netherlands, Germany, Poland, Belarus, Russia, Kazakhstan, China, the Philippines, Indonesia and Australia and could have been a little longer, since at the time of landing the aircraft had a fuel reserve of 6300 kg for a flight for another 1 hours 45 minutes. In total, 100 kg of fuel were consumed during the flight.

On board, in addition to the crew members, there were several dozen passengers and scientists from Australia, who observed the condition of people during a long flight. At the same time, dinner was served to passengers, and the flight itself simulated a flight at night, since the flight was operated according to Sydney time. Qantas stressed that this is the second non-stop flight from London to Sydney in the history of civil aviation, after a test flight in 1989 on a Boeing 747-400.

The information collected during this and previous flights will allow scientists and the airline to develop a methodology that is optimal for human health for such long non-stop flights. Qantas is about to conduct another similar flight.

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