LED lamp. Scheme, description

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

LED lamp. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Lighting

Comments on the article

Currently, a new problem has arisen - saving electricity. To solve this problem, an increasing number of companies are producing fluorescent energy-saving lamps with an E27 and E14 base. The energy consumption of these lamps is undoubtedly much less than conventional incandescent lamps. Also, the claimed service life is approximately 4000 hours, i.e. about 4 times the life of a conventional lamp.

With all these advantages, this lamp has a drawback, such as a high price. These lamps use a special electronic ballast, but, as a rule, it fails extremely rarely, but the filaments of a fluorescent lamp burn out quickly enough, often without even a guaranteed service life, which makes their repair almost impossible. However, now there are high-brightness LEDs that can also be used for lighting. The service life of modern LEDs is approximately 50000 hours, which is almost 6 years of continuous operation.

The LED lamp brought to your attention was specially developed for illumination and food from the alternating current main of 220 V.

The scheme of this lamp, shown in fig. 1 is quite simple, and does not need adjustment. A distinctive feature of the presented lamp is the use of wide-angle LEDs, which results in a uniform and bright illumination over the entire area. Also, the advantages of this lamp include very low power consumption (about 2 W) and high efficiency.

(click to enlarge)

The main elements of the circuit are light-emitting diodes (25 pieces) of a white emission spectrum, increased brightness. As HL1...HL25 diodes, it is better to use wide-angle (160°) 5WW4SC type LEDs. They can be replaced by any other wide-angle LEDs with a forward voltage of 3,2...3,7 V and a current of 20 mA.

To power the LEDs, a transformerless power supply circuit is used, consisting of a quenching capacitor C1, a discharge resistor R1, a diode bridge VD1 ... VD4, a smoothing capacitor C2 and a limiting resistor R2. The alternating mains voltage is extinguished by the circuit R1, C1, R2. Capacitor C2 must be designed for an operating voltage of at least 250 V. Further, the reduced voltage is supplied to the rectifying diode bridge, and after the capacitive filter (C2), a constant voltage is supplied to the series-connected LEDs HL1 ... HL25. When using 37 LEDs in the circuit, you can eliminate the resistor R2.

A scheme was also provided for protecting the LEDs from increased mains voltage and from its surges. It is built on fuse F1 and varistor RU1. A varistor (semiconductor resistor) has a symmetrical current-voltage characteristic, due to which it can be used in AC circuits as a control element. When the mains voltage increases, the resistance of the varistor decreases, and the current flowing through it increases, as a result of which the F1 fuse blows, and the rest of the expensive circuit remains operational. TVR 1 05 or FNR 361 05 can be used as varistor RU361. Due to the lack of a fuse with a lower current, the burnout had to be set to 80 mA, although it is desirable to use a fuse of 40 mA.

All circuit elements are mounted on foil-coated fiberglass. LEDs are arranged in a circle in three rows. Socles (E14, E27) from energy-saving lamps are best suited as a housing. All parts fit very well inside this case. It is best to fix the board in the case with hot glue.

The assembled lamp is shown in fig. 2.

LED lamp

Attention! When assembling this circuit and testing it, you must be very careful, because. the circuit is not galvanically isolated from the AC mains!

Author: E. Pereverzev Krasnodar Territory, Kropotkin

See other articles Section Lighting.

<< 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

Good cholesterol protects the liver from inflammation 30.07.2021

"Good" and "bad" cholesterol are called different types of lipoprotein particles - large transport complexes of lipids and proteins. "Bad cholesterol", that is, low-density lipoproteins (LDL, or LDL), are bad because they increase the likelihood of atherosclerosis: lipids from such particles tend to accumulate in the walls of blood vessels, contributing to the formation of atherosclerotic plaques. "Good cholesterol", that is, high-density lipoproteins (HDL, or HDL), are good in that they do not increase the likelihood of atherosclerosis. At the same time, it is believed that it is best when both "bad" and "good" cholesterol float in the blood less.

However, both low and high density lipoproteins have varieties. And among the "good cholesterol" there are particles called HDL3, which are good for the liver. The fact is that from time to time bacterial lipopolyscharide, fragments of the cell wall of bacteria living in the intestine, enters the liver. These bacterial fragments cause immune cells to react, and a flaccid inflammation begins in the liver. And as you know, inflammation harms not only infections, but also healthy tissues; due to inflammation, healthy cells die, they are replaced by connective tissue, and as a result, the organ no longer functions as well as it should.

Employees of Washington University in St. Louis write in Science that "good" lipoprotein particles such as HDL3 enter the liver along with the blood and interact here with the LBP protein, or lipopolysaccharide-binding protein. As the name suggests, LBP traps bacterial lipopolysaccharide and in doing so stimulates immune cells in the liver. But if LBP has connected with HDL3, then it does not react to bacterial fragments and does not stimulate immune cells.

In mice that did not produce enough HDL3 (due to genetic manipulation or because the part of the intestine in which HDL3 is formed was removed from them), inflammation in the liver increased so much that it led to fibrosis, connective tissue degeneration. Debris of bacterial cells, of course, should be removed in a timely manner, but the immune signals in the liver that arise in response to bacterial debris are unreasonably strong, and local immune cells start completely unnecessary inflammation here. If HDL3 is present in sufficient quantity, they curb inflammation. What's more, there are now experimental drugs that increase HDL3 levels, and these drugs have been able to reduce liver inflammation in mice and keep the liver healthy.

Molecular complexes of HDL3 and LBP are also formed in humans, which means that the same mechanism of protection of the liver can work in us. If this is the case, then it remains only to develop HDL3-enhancing drugs for humans - such drugs could be a good remedy for various liver diseases associated with inflammatory processes.

Other interesting news:

▪ Wireless TV

▪ Dangerous sequins

▪ Recycling disposable masks into fuel

▪ Video cameras detect crimes

▪ Wireless powered maglev train

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site for those who like to travel - tips for tourists. Article selection

▪ article We met somewhere! Popular expression

▪ article How many times has the man who journalists call the luckiest person in the world survived in disasters? Detailed answer

▪ article Seamstress (seamstress-mechanic, seamstress-manual) when working on machines or manually. Standard instruction on labor protection

▪ article Electroceramic materials and glasses. Encyclopedia of radio electronics and electrical engineering

▪ article Heat sink overheating indicator. 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