Emergency lamp using LED strip. Scheme, description

Free technical library

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

Emergency lamp using LED strip. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Lighting

Comments on the article

There are many designs of fixtures using super-bright LEDs. Often their number is measured in tens, which requires quite a lot of labor for the manufacture of circuit boards and the installation of LEDs on them. However, this can be avoided by using the so-called LED strip in the lamp. It consists of 12-volt (rarely 18- or 24-volt) cells connected in parallel, each of which contains three (four, six) LEDs connected in series in a surface-mount package and a current-limiting resistor.

On one meter of such a tape, from 60 to 240 LEDs are placed. The manufacturer of the LED strip has already done the painstaking work on their installation, you just have to cut off a fragment of the required length from it and solder two leads.

By selecting the number of cells in the fragments and using their serial and parallel connections, it is possible to manufacture a luminaire with the required lighting characteristics and optimal voltage and current values for the existing power source.

(click to enlarge)

As an example of the use of LED strip, the figure shows a diagram of a device designed for night and emergency lighting of a large (about 400 m2) warehouse, the darkness in which is unacceptable, since surveillance cameras are installed in it.

Luminaires EL1-EL5, each of which is a piece of LED strip NLS-3528WW60-4,8-IP20-12V of 10 cells (30 LEDs), are located around the perimeter of the room. They are powered by a stabilized 60...67 V source with a backup battery and turn on automatically when the electric lighting is suddenly turned off, as well as at the end of the working day, when the lights go out in the warehouse. At the same time, CCTV cameras are able to increase their sensitivity, and the indicated number of LEDs is quite enough for their work in standby mode.

The device that provides automatic switching on and off of the lamp is made on transistors VT1 and VT2. Through resistors R1, R2 and a step-down transformer T1, it is connected to the nearest conventional electric lighting fixture. If there is a mains voltage on it, the transistor VT1 is opened by the rectified diode VD1 by the voltage of the secondary winding of the transformer T1 and shunts the gate-source circuit of the powerful field-effect transistor VT2, so it is closed and the EL1-EL5 lamps are de-energized. A power failure at the standard lighting fixture leads to the fact that the transistor VT1 closes, and VT2 opens, closing the power supply circuit of the LED lamps from a backup source. Parallel stabilizer DA1 protects fixtures from high voltage and impulse noise. The protection operation voltage (within 70.72 V) is set by selecting the resistor R7.

The device is assembled on a breadboard. Resistors - MLT, C2-33 and the like, capacitors C1, C2 - imported oxide, C3 - ceramic KM-5 with a rated voltage of 100 V. For galvanic isolation of the control circuit of the device from the network, I used a step-down transformer (T1) with a transformation ratio of about 30 from the subscriber loudspeaker. You can use other transformers by selecting resistors R1 and R2 so that the alternating voltage on the secondary winding with the standard lighting turned on becomes approximately 1 V.

To set up protection, instead of LED lamps, a conventional 40 W incandescent lamp is temporarily connected, and the resistor R7 is replaced with a variable rheostat or a tuning resistor with a resistance of 47.68 kOhm. By setting its engine to the position corresponding to the maximum resistance, and controlling the output voltage with a digital voltmeter, change the resistance of the resistor, achieving a sharp loss of the output voltage when the input voltage is increased to 70.72 V. After that, the resistor is soldered, the resistance between the terminals of the resistive element is measured and replaced with a constant of the same resistance . To facilitate selection, R7 can be made up of two resistors connected in series or in parallel.

Author: V. Karlov

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

An hour and a half of music on your mobile phone 27.07.2000

The new model of Samsung SGH-M100 mobile phones has a built-in flash memory that allows you to store half an hour of music in MPXNUMX format, images and other files.

This model allows you to download music files from the Internet and listen to them through headphones.

Other interesting news:

▪ Prosthetic arm rocket engine

▪ In 40 years, the Arctic will lose ice

▪ Nvidia Tegra X1 Mobile Superchip

▪ Created a battery that can last up to 400 years

▪ paper batteries

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Data transfer. Article selection

▪ article We would only stand the night and hold out the day. Popular expression

▪ article What ants grow their homes through agricultural activities? Detailed answer

▪ article Snowberry racemosus. Legends, cultivation, methods of application

▪ Article Toilet soap. Simple recipes and tips

▪ article Harmonic filters for KB and CB radio stations. 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