Option for mechanism drive switch. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Clocks, timers, relays, load switches
Comments on the article
The simplest and most frequently repeated technical task is to ensure that one or another mechanism performs one cycle of movement, after which it must stop in its original position. At the next command - pressing the "Start" button - the cycle should repeat. The problem can be solved using the well-known simple circuit shown in Fig. one.
When the contacts of the button SB2 "Start" are closed, relay K1 is activated, its contacts K1.2 turn on the mechanism drive. After some time, the contacts of the limit switch SF1 are closed, after which the relay K1 self-locks with its contacts K1.1. At the end of the cycle, one of the links of the mechanism opens the contacts of the limit switch SF1 and de-energizes the relay winding, it releases the armature, which opens the contacts K1.1 and K1.2 - the mechanism stops. Button SB1 "Stop" - emergency, forcibly stopping the cycle.
This simple device, however, has a drawback that is not immediately noticeable. It consists in the fact that after the mechanism stops, the limit switch contacts remain open, and the next time the cycle is started, the "Start" button must be held down until they close. In some cases, this disadvantage does not manifest itself in any way, but at a low speed of movement of the links of the mechanism it creates noticeable inconvenience. If an unexpected interruption of the cycle is unacceptable, the described device cannot be used.
This drawback is often eliminated by introducing a time relay into the device, blocking the limit switch for the period of starting the mechanism. The delay time of the relay must be greater than the open time of the SF1 contacts, but less than the cycle time. If the cycle duration needs to be changed over a wide range, it is necessary to reset the delay time of the time relay, which makes the device unsuitable for practice.
The device, assembled according to the scheme in Fig. 2 is free from the said disadvantage. The contacts of the limit switch SF1 are not closed here, but open. Pressing the "Start" button opens the trinistor VS1, as a result of which relay K1 is activated and turns on the mechanism drive. When approaching the end of the cycle, the contacts of the limit switch are closed, which leads to the closing of the trinistor. The relay remains on until the contacts SF1 open. This corresponds to the initial position of the mechanism.
The scheme in fig. 3 is not fundamentally different. Here, only the order of the serial connection of the trinistor and the relay has been changed. But it sometimes turns out to be more convenient to install. The type of relay and trinistor is selected based on the specific operating conditions of the device.
Author: Yu. Kalashnikov, Voronezh; Publication: radioradar.net
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 Container ship on methanol
16.09.2023
Maersk has completed construction and unveiled the world's first container ship that runs on methanol. The new ship was named Laura Maersk in honor of the company's first steamship. The move comes as part of Maersk's ambitious 2040 plan to eliminate greenhouse gas emissions and transport at least 25% of ocean cargo using clean fuels by 2030.
Laura Maersk, with a capacity of 2100 TEU (twenty-foot equivalent units), represents an important milestone towards the company's long-term goal of gradually renewing the entire Maersk fleet to use exclusively clean fuels.
As part of this strategy, Maersk has already placed an order for the construction of a further 24 methanol-fueled vessels between 2024 and 2027.
Vincent Clercq, CEO of Maersk, emphasized the importance of this milestone: “Laura Maersk is a historic milestone for global shipping. She demonstrates the entrepreneurial spirit that has always characterized Maersk since its founding. However, more importantly, this ship is a real testament to that "That concentrated efforts and partnerships across our industry are creating a strong and optimistic path to a sustainable future. This new green ship is the breakthrough we need, but we still have a long way to go to achieve net-zero emissions."
|
Other interesting news:
▪ TCPP01-M12 chip for protecting USB type-C lines
▪ Nanowire networks learn and remember like the human brain
▪ A laser the size of a virus particle
▪ The device monitors the health of the pilot
▪ Advanced technology for recycling waste office equipment
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Mobile communications. Article selection
▪ article Artificial radioactivity. History and essence of scientific discovery
▪ article What is carbon? Detailed answer
▪ article by Georg Ohm. Biography of a scientist
▪ photophone article. Transmission of sound using a beam of light. Encyclopedia of radio electronics and electrical engineering
▪ article Switch-on signaling device in the mains plug. 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