Contactless control of power circuits up to 10 amperes. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Clocks, timers, relays, load switches
Comments on the article
In amateur radio practice, it is often necessary to control powerful electrical appliances, such as heaters, electric motors, etc. A timer, a remote control signal receiver, an acoustic sensor, etc. can act as a control device. The main thing is that the output control signals be TTL or CMOS level. In addition, control circuits must be galvanically isolated from power circuits. Without such a decoupling, the operation of an electronic device is dangerous!
A variant of the control scheme is shown in the figure. It uses a powerful triac TS106-10, which allows you to switch the load with a maximum current of up to 10 A. For galvanic isolation of the control and power circuits, an optodistor, AOU103B, is used. A triac (symmetric thyristor) can operate in both half-cycles of an alternating voltage, i.e. in the open state, it passes both positive and negative half-waves of the mains voltage.
To turn off the load, the input must be given a high logic level ("1"). In this case, the VT1 key closes, the current does not flow through the photodinistor LED, and the triac is closed. To turn on the load, a logical "0" is supplied from the control circuit. Transistor VT1 opens, the photodinistor LED lights up and illuminates the dinistor. The dinistor opens in each half cycle of the voltage. Through the diode bridge VD1, the dinistor is connected to the control electrode of the triac VS1. Therefore, at the beginning of each half-cycle, the triac also opens, and the full supply voltage is supplied to the load. As VD1, you can use any low-power rectifier bridge, or make it up of four diodes (KD105 or similar). LED HL1 (any type) is used to indicate the inclusion of the load.
To adjust the power of the load (heater), the control device must generate low-level pulses synchronized with the mains voltage. The shift of these pulses relative to the beginning of the half-cycle of the mains voltage will cause a delay in the opening of the optodistor and, accordingly, the triac. As a result, only part of the mains voltage will be supplied to the load.
Author: A.Kashkarov, St. Petersburg
See other articles Section Clocks, timers, relays, load switches.
Read and write useful comments on this article.
<< Back
Latest news of science and technology, new electronics:
Machine for thinning flowers in gardens
02.05.2024
In modern agriculture, technological progress is developing aimed at increasing the efficiency of plant care processes. The innovative Florix flower thinning machine was presented in Italy, designed to optimize the harvesting stage. This tool is equipped with mobile arms, allowing it to be easily adapted to the needs of the garden. The operator can adjust the speed of the thin wires by controlling them from the tractor cab using a joystick. This approach significantly increases the efficiency of the flower thinning process, providing the possibility of individual adjustment to the specific conditions of the garden, as well as the variety and type of fruit grown in it. After testing the Florix machine for two years on various types of fruit, the results were very encouraging. Farmers such as Filiberto Montanari, who has used a Florix machine for several years, have reported a significant reduction in the time and labor required to thin flowers.
... >>
Advanced Infrared Microscope
02.05.2024
Microscopes play an important role in scientific research, allowing scientists to delve into structures and processes invisible to the eye. However, various microscopy methods have their limitations, and among them was the limitation of resolution when using the infrared range. But the latest achievements of Japanese researchers from the University of Tokyo open up new prospects for studying the microworld. Scientists from the University of Tokyo have unveiled a new microscope that will revolutionize the capabilities of infrared microscopy. This advanced instrument allows you to see the internal structures of living bacteria with amazing clarity on the nanometer scale. Typically, mid-infrared microscopes are limited by low resolution, but the latest development from Japanese researchers overcomes these limitations. According to scientists, the developed microscope allows creating images with a resolution of up to 120 nanometers, which is 30 times higher than the resolution of traditional microscopes. ... >>
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 ... >>
| Random news from the Archive The longest living creatures on Earth have been found
23.07.2017
American scientists have discovered the longest-lived creatures on Earth, the secret of which they hope to use to extend human life. These are deep sea sessile worms from the bottom of the Caribbean Sea, some of which are over 300 years old.
Individuals of Escarpia laminata cross a border in longevity that no other species of living creatures has ever crossed. And since it is impossible to accurately determine the age for the longest individuals of this species, it is possible that some of them live even longer.
Worms are more suitable for experimentation and study than rare tortoises and giant cetaceans, which were previously considered long-lived record holders. Individuals living in one place all their lives near hydrothermal vents and "black smokers" at the bottom of the sea feed on plankton and the remains of other organisms that are caught from the water. Escarpia laminata tubes grow very slowly - about half a millimeter per year, and the age of the longest individuals exceeds 300 years.
Part of the secret to their longevity is that these worms almost never die - the mortality rate in their colonies does not exceed 0,6% even for the oldest individuals, which is about 15 times lower than the values \uXNUMXb\uXNUMXbpredicted by theory. Perhaps this is due to the low temperature of the waters in which Escarpia laminata and other deep-sea worms live.
|
Other interesting news:
▪ Production of superdiamonds
▪ 32/64-bit processor from Intel
▪ Microchips 3D TLC NAND 32 GB
▪ Two-channel DC/DC converter for powering screens of portable devices
▪ Smart Button for IoT
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Dosimeters. Selection of articles
▪ article Shabby look. Popular expression
▪ article Which monster was inspired by the scars of nuclear bomb survivors? Detailed answer
▪ article Glass sheet edging line operator. Standard instruction on labor protection
▪ article Antenna current indicator. Encyclopedia of radio electronics and electrical engineering
▪ article Power supply and electrical networks. Categories of electrical receivers and ensuring the reliability of power supply. Encyclopedia of radio electronics and electrical engineering
Leave your comment on this article:
All languages of this page
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua
2000-2024
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese