Powerful laboratory power supply for repairing electrical equipment and charging batteries, 1,5-30 volts 25 amps. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Power Supplies
Comments on the article
Being engaged in the repair or development of automotive electronics, charging batteries, you are faced with the problem of stationary power supply for these devices.
The power supply described below is designed just for such purposes. It produces a current in the load up to 25 A, the output voltage is smoothly regulated within 1,5 ... 30 V.
The source diagram is quite simple. The voltage from the power transformer is rectified by a full-wave rectifier on diodes VD1 - VD6. The parallel connection of diodes made it possible to use relatively affordable KD21ZA diodes.
The voltage from the output of the rectifier is supplied to the integrated stabilizer DA1 - KP142EH12, at the output of which, using the resistor R1, a constant voltage is regulated from 1,5 to 30 V. The output current of DA1 is not more than 1,5 A, therefore, a powerful emitter is switched on at its output repeater on three powerful transistors connected in parallel VT1 - VT3.
The power transformer is based on the TS200 from an old tube TV. This transformer needs to remove all secondary windings, leaving only the mains (marked 1 - 3 and 1' - 3'). New secondary windings are wound with PEV-1 0,96 wire and contain 87 turns each.
The body of the device is metal, on its side walls there are two massive aluminum plates, which serve as radiators for transistors and diodes.
The plates are insulated from the case with mica and thermal paste. In principle, the case can be used as a radiator, but in this case, it is necessary to avoid contact with the general minus of the device, or with other current-carrying buses or cases of other laboratory devices, or place the radiator plates over the entire area of the sidewalls, at a small distance from them, and in drill a lot of ventilation holes on the sidewalls themselves.
It is possible to use a developed finned radiator together with electric fans from a personal computer.
Author: Shelestov I.P.
See other articles Section Power Supplies.
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 Bacterial vampirism
28.04.2024
Some of the deadliest bacteria react to human blood and rush to it, since its serum contains substances that serve as food for them. American scientists studied this phenomenon, which was called “bacterial vampirism.”
The Enterobacteriaceae family of bacteria includes both representatives of the normal microflora of the human body and a large number of pathogens, including salmonella and E. coli.
Some enterobacteriaceae are associated with gastrointestinal bleeding and bacteremia and are considered a leading cause of death from sepsis in people with inflammatory bowel disease. However, the behavior of these microorganisms and the mechanisms that encourage them to enter the bloodstream are not well understood. A team of specialists from the University of Washington and the University of Oregon (both in the USA) took on the task of filling the gap.
Researchers have found that blood serum attracts at least three types of pathogenic bacteria: Salmonella enterica, Escherichia coli and Citrobacter koseri. One of the substances attractive to them was the amino acid L-serine present in the blood, which is involved in the construction of almost all natural proteins. By the way, it is often included in protein shakes.
Using an experimental setup called the Chemosensory Injection Rig Assay (CIRA), developed by one of the authors, the researchers simulated intestinal bleeding outside a living organism and used a powerful microscope to observe in real time the reaction of pathogens to tiny injections of blood serum. It took the bacteria less than a minute to find a “food source.”
In addition, the study revealed that Salmonella bacteria have a special protein receptor Tsr, which allows them to hear blood serum and be directed to it. Using protein crystallography, the scientists were able to see how the chemoreceptor atoms bind to L-serine. It is through this mechanism that bacteria recognize the amino acid and then consume it.
By mapping the phylogenetic distribution of the Tsr chemoreceptor, the researchers discovered its presence not only among Enterobacteriaceae, but also in the families Morganelliaceae and Yersiniaceae. This suggests that other pathogenic microorganisms are also capable of reacting to blood serum.
By understanding how bacteria can detect the source of bleeding, a new drug that blocks this ability could be developed in the future. Such drugs will help improve the lives and health of patients with inflammatory bowel disease, who are at high risk of bloodstream infections.
|
Other interesting news:
▪ Neural noise helps you learn
▪ too good memory
▪ Infineon P600 7V CoolMOS Transistors
▪ Test tube beef steak
▪ Efficient hemp supercapacitors
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Signal limiters, compressors. Article selection
▪ article Superconductivity. History and essence of scientific discovery
▪ article Where are the foreign countries in Europe? Detailed answer
▪ article Maintenance of steam boilers for gaseous fuels. Standard instruction on labor protection
▪ article AL307 highlights the scale. Encyclopedia of radio electronics and electrical engineering
▪ article Resettable fuse, 5 amps. Encyclopedia of radio electronics and electrical engineering
Leave your comment on this article:
Comments on the article:
Ali-bastr
Or am I already completely blind, or are there no filter capacitors at all? Then a TC200 transformer with a power of 200 watts. And the output voltage of the power supply is 30V at 25 amperes. That's 750 watts! Almost four times the power of the transformer. I am already silent about other incidents. Something doesn't fit here...
Fedotov G.V.
We read the article more carefully: 1. The stabilizer is used to charge a car battery. Ripple for the battery is not relevant. The filter capacitor can be omitted in this case; 2. The maximum current is indicated: "...UP TO 25 amperes". It will be at an output voltage of up to 10V. At 30 V, respectively, about 6,5 amperes. 3. The previous comment was written by a theorist girl. The developer writes that the scheme will be exploited, which is what he wants for you !!! Keep knitting girl!
Alexander
Where did the current 25 amps come from? With a diameter of 1 mm, a total cross section of 1.5 mm is a maximum of 6 amperes.
Alexander
Fedotov G.V. You have not gone far from the theoretician's girl. Where is the protection? And do not confuse the transistor with a water tap, it limits it and does not heat up.
Anatoly
... devices at the exit are also not frail.
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