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

The simple luminaire with super-bright white LEDs offered to the attention of readers was designed for evening lighting of a computer workplace instead of an uneconomical and very hot luminaire with an incandescent lamp and a phase power regulator.

The choice of LEDs instead of the so-called "energy-saving" fluorescent lamps was made for the reason that such lamps very often fail, and it is the fluorescent tube that fails that cannot be repaired, and not the voltage converter built into the lamp. The second reason is that it is quite difficult to adjust the brightness of a fluorescent lamp.

LED lamp
Fig. 1

The scheme of the LED lamp is shown in fig. 1. It has three fixed brightness values, which are selected by the SA1 switch, changing the current flowing through the EL1 - EL10 LEDs. In the upper (according to the diagram) position of the switch, the current is about 20 mA, on average - 6 mA, in the lower position - 2 mA.

Resistor R1 reduces the amplitude of the charging current surges of the lamp capacitors that occur when it is connected to the network or the position of the switch SA1 changes. Capacitor C4 smoothes the voltage supplied to the LEDs rectified by the diode bridge VD1. This not only increases the brightness of their glow, averaged over a half-cycle of the mains voltage, but also eliminates especially dangerous for LED current overload at peak ripples. The voltage across capacitor C4 when using LEDs of the type indicated in the diagram should be about 30,7 V when switch SB1 is set to the top position.

The lamp was mounted in a plastic case 202x25x20 mm in size, intended for a toothbrush (Fig. 2). The parts are glued to the case with "Moment-1" glue (rubber). Other suitable adhesives can also be used.

LED lamp
Fig. 2

Switch SA1 - sliding three positions from an old portable tape recorder. Resistor R1 is desirable to install an imported discontinuous one. Capacitors C1-C3 - film K73-17, K73-24, K78-2 or similar imported ones for an operating voltage of at least 630 V DC Sometimes the permissible AC voltage is indicated on imported capacitors (with the sign "~" or "AC") . It must be at least 250 V.

The diode bridge KTS407A can be replaced with DB104-DB107, RB154-RB157 or four single rectifier diodes, for example, 1N4004, KD243Zh, KD105G ), RL504-WH50D (744mm, 5mCd), RL8000-WH30D (744mm, 5mCd), DB5000D-80AWD (744mm, 8mCd), RL8000-WH10D (Zmm 439mCd). Preference should be given to LEDs in larger diameter cases.

Before turning on the luminaire for the first time, make sure that the LEDs are connected in series and connected to the capacitor C4 in the correct polarity. After disconnecting from the network, a weak glow of its LEDs in a dark room will be noticeable for another 2 ... 3 minutes. If one of the LEDs of the same type goes out much earlier than the others, it may have been overheated during soldering, or just a defective copy has come across. It is advisable to replace this LED.

At the maximum brightness of the lamp, installed at a height of 1,5 m above the desktop, the illumination created by it is sufficient to type text on a computer keyboard. With a minimum brightness, the lamp can serve as a night light.

Author: A. Butov, p. Kurba, Yaroslavl region; Publication: radioradar.net

See other articles Section Lighting.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

A New Way to Control and Manipulate Optical Signals 05.05.2024

The modern world of science and technology is developing rapidly, and every day new methods and technologies appear that open up new prospects for us in various fields. One such innovation is the development by German scientists of a new way to control optical signals, which could lead to significant progress in the field of photonics. Recent research has allowed German scientists to create a tunable waveplate inside a fused silica waveguide. This method, based on the use of a liquid crystal layer, allows one to effectively change the polarization of light passing through a waveguide. This technological breakthrough opens up new prospects for the development of compact and efficient photonic devices capable of processing large volumes of data. The electro-optical control of polarization provided by the new method could provide the basis for a new class of integrated photonic devices. This opens up great opportunities for ... >>

Primium Seneca keyboard 05.05.2024

Keyboards are an integral part of our daily computer work. However, one of the main problems that users face is noise, especially in the case of premium models. But with the new Seneca keyboard from Norbauer & Co, that may change. Seneca is not just a keyboard, it is the result of five years of development work to create the ideal device. Every aspect of this keyboard, from acoustic properties to mechanical characteristics, has been carefully considered and balanced. One of the key features of Seneca is its silent stabilizers, which solve the noise problem common to many keyboards. In addition, the keyboard supports various key widths, making it convenient for any user. Although Seneca is not yet available for purchase, it is scheduled for release in late summer. Norbauer & Co's Seneca represents new standards in keyboard design. Her ... >>

The world's tallest astronomical observatory opened 04.05.2024

Exploring space and its mysteries is a task that attracts the attention of astronomers from all over the world. In the fresh air of the high mountains, far from city light pollution, the stars and planets reveal their secrets with greater clarity. A new page is opening in the history of astronomy with the opening of the world's highest astronomical observatory - the Atacama Observatory of the University of Tokyo. The Atacama Observatory, located at an altitude of 5640 meters above sea level, opens up new opportunities for astronomers in the study of space. This site has become the highest location for a ground-based telescope, providing researchers with a unique tool for studying infrared waves in the Universe. Although the high altitude location provides clearer skies and less interference from the atmosphere, building an observatory on a high mountain poses enormous difficulties and challenges. However, despite the difficulties, the new observatory opens up broad research prospects for astronomers. ... >>

Random news from the Archive

ODROID-GO Advance Retro Game Console 03.01.2020

The South Korean company Hardkernel has introduced an updated version of its own portable retro game console called ODROID-GO Advance, which is able to emulate different platforms that were popular in the past.

The console received a 3,5-inch LCD display with a resolution of 480 x 320 pixels, which is enclosed in a transparent plastic case. To interact with the gadget, there are 10 input buttons, an analog joystick, and a direction indicator.

The hardware basis of the device is a Rockchip RK3326 single-chip system with four Cortex-A35 processing cores operating at a frequency of up to 1,3 GHz. The Mali-G31 MP2 accelerator is responsible for graphics processing. The configuration is complemented by 1 GB of DDR3L RAM, as well as 16 MB of SPI Flash memory for the bootloader.

There is a slot for a microSD memory card, a standard 3,5 mm headphone jack, a USB 2.0 interface, and a 0,5 W mono speaker. A 3000 mAh rechargeable battery is used as a power source, which is enough for continuous gaming for 10 hours.

ODROID-GO Advance has dimensions of 155 x 72 x 20 mm and weighs 170 g. The software base is based on 64-bit Ubuntu 18.04 (Linux kernel 4.4.189) with an EmulationStation interface with Libretro and OpenGL-ES acceleration on DRM-FB. The console is capable of emulating the following retro platforms:

Atari 2600, Atari 5200, Atari 7800, Atari Lynx,
SEGA Game Gear,
Nintendo Game Boy, Game Boy Advance, Game Box Color,
SEGA Master System, SEGA Mega Drive (Genesis),
Nintendo NES, SNES,
NEC PC Engine, PC Engine CD,
Sony PlayStation, Portable PlayStation,
Sega CD (Mega CD).

It is expected that the game console will support more platforms in the future. The price of the novelty is $55.

Other interesting news:

▪ Processing carbon dioxide into rocket fuel

▪ SMS for trolleybuses

▪ SilverStone LSB02 backlight controller for PC

▪ Fine grinding for the pig

▪ Voice control of LG air conditioners

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Security and safety. Article selection

▪ article Put your teeth on the shelf. Popular expression

▪ article How did British intelligence deceive Hitler so that the Allies could capture Sicily without interference? Detailed answer

▪ article Specialist (expert, consultant) on personnel and personnel work. Job description

▪ article Logical elements and truth tables. Encyclopedia of radio electronics and electrical engineering

▪ article Mechanical power supply for MP3 player. 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