Dual channel LED flash controller. Scheme, description

Free technical library

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

Dual channel LED flash controller. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Lighting

Comments on the article

A flash lamp is a very popular element of decorative lighting for a wide variety of objects. It finds application in discotheques, in the design of shop windows and illuminated advertisements. Such lamps are also used by cyclists who pay serious attention to their safety on the road. Installing flash lamps on objects at a great distance from the observer creates the effect of iridescent light flicker and is very spectacular. Numerous flickering lights hovering against the dark sky above the roofs of buildings make an indelible impression.

Traditionally, flash lamps were gas-discharge lamps, which required a high voltage source to power them and severely limited the frequency of flashes, as well as their total number before the lamp was exhausted. But the bright LED flash lamps that have appeared today are certainly a big step forward in terms of manufacturability, economy and durability.

Dual Channel LED Flash Controller
Fig.1-2

The proposed device allows you to control two LED lamps or their sets. It is built according to the scheme shown in Fig. 1, and is equipped with a PIC12F675 (DD1) microcontroller. From the trimmer resistor R7, a voltage is supplied to the analog input AN 1 of the microcontroller, which sets the duration of flashes in the range of 0,1 ... 1 s. The voltage supplied to the AN0 input from the tuning resistor R4 sets the number of flashes following one after another in each channel (from 1 to 10). By operating with tuning resistors, you can choose the optimal lighting effect.

Field-effect transistors VT2 and VT4 amplify the control signals generated at the outputs GP4 and GP5 of the microcontroller for each channel. Accelerating the closing of field-effect transistors, the discharge of their gate-source capacitance is provided by bipolar transistors VT1 and VT3.

12 V LED lamps for both channels are connected to the XT2 screw block. The operation of each channel can be controlled by the flashes of the HL1 and HL2 LEDs.

A constant supply voltage of 12 V is supplied to the XT 1 block. The VD1 diode will protect the device if the voltage polarity is accidentally reversed. The supply voltage of the microcontroller is stabilized by the integral stabilizer DA1.

The device is made on a single-sided printed circuit board with dimensions of 84x28 mm (Fig. 2).

The voltage stabilizer 7805 can be replaced by the domestic analogue KR142EN5A, and the KT3107A transistors can be replaced by any of the same series, the KT502 series or BC557 transistors. Instead of IRFZ44N field effect transistors, IRFZ46N or IRFZ48N can be used. Diodes KD522B replace, for example, imported 1 N4148.

Trimmer resistors R4 and R7 - SPZ-386 or their imported analogues SH-085 with ratings from 10 to 100 kOhm. They must be with a linear control characteristic (A - for domestic, B - for imported resistors).

Automotive LED lamps can be connected to the controller, as well as both self-assembled and ready-made LED panels designed for 12 V power supply. LEDs of any glow color can be installed in them.

PCB file in Sprint Layout 5.0 format and microcontroller program of this device can be downloaded hence.

Although the field-effect transistors used in the device are capable of switching a current of several tens of amperes, the actual load capacity is limited by the VD1 diode, designed for a current of not more than 1A. To control LED lamps that consume more current, it is necessary to replace this diode with a more powerful one and, possibly, VT2 heatsinks.

Author: G. Nosov, Saratov; 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

Smart speaker Redmi XiaoAI Touch Screen Speaker 29.03.2020

Redmi introduced the smart speaker Redmi XiaoAI Touch Screen Speaker.

A feature of the device is a large 8-inch display with HD resolution - with its help, not only control is carried out, but also video telephony: a web-camera is built into the column case. By the way, the operation of the children's mode is also tied to it: as soon as the camera detects a child in front of it, the column switches to a special mode of operation with displaying only children's content.

The third generation XiaoAI proprietary voice assistant is built into the device. It provides access to a variety of functions, including control of smart home devices. Redmi XiaoAI Touch Screen Speaker supports various video and audio streaming services, so such a device will not be superfluous in times of quarantine and self-isolation.

The price of new items is $50.

Other interesting news:

▪ Hyundai car with Google Glass and SoundHound

▪ Biodegradable displays for green electronics

▪ Gut microflora affects our health and mood

▪ house on a corkscrew

▪ Artificial sperm created

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Electronic directories. Article selection

▪ article Blanket for concrete. Tips for the home master

▪ article Where do sea gypsies live, and what do they do? Detailed answer

▪ article The functional composition of Tamashi TVs. Directory