Category Archives: LEDS

How Efficient are Light Emitting Diodes – LEDS?

Almost all commercial and residential establishments are moving over to light emitting diode (LED) illumination, as they are guaranteed to be more efficient compared to other forms of lighting such as incandescent and fluorescent. Unless designed with care, LEDs can suffer from premature failure due to thermal issues. Under thermal stress, LEDs can permanently lose their brightness, while degrading much quicker than the manufacturer intended. That means designers and engineers need to balance the Read more [...]

Intelligence in LED Lighting

Apart from illuminating dark spaces there is much more to LED lighting than otherwise thought of. LEDs can be connected in an intelligent network with a low-voltage IP-based infrastructure, and they become a part of a powerful network of systems. Such a system can cooperatively collect, analyze, manage, control, and respond to specific objectives based on real-time sensor feedback. The building lit up by these LEDs now behaves as a smart building, offering better operational performance. It responds Read more [...]

Charlieplexing on the Raspberry Pi

If you suddenly find the need to control many LEDs and do not have the requisite electronics to do so, you can turn to your single board computer, the Raspberry Pi (RBPi) and use it to charlieplex the LEDs. Charlieplexing is named after Charlie Allen, the inventor of the technique. Charlieplexing takes advantage of a feature of the GPIO pins of the RBPi, wherein they can change from outputs to inputs even when the RBPi is running a program. Simply setting a GPIO pin to be low does not allow enough Read more [...]

Dimming LEDs with PWM Generator

nlike incandescent bulbs, dimming Light Emitting Diodes (LEDs) is not an easy task. Incandescent bulbs operate on alternating voltage supply, whereby using Triacs, one can control the effective RMS voltage applied to the bulb. Moreover, since the incandescent bulbs are resistive elements, a simple reduction is voltage is sufficient to reduce the current through it, thereby reducing its light and heat output. LED operation is different, as they work on direct voltage. Each LED requires an optimum Read more [...]

Blinkt! is Compatible with the Raspberry Pi

If you are interested in learning how to control RGB LEDs with the Raspberry Pi (RBPi) single board computer, Blinkt! provides a simple way to interface. Blinkt! is a strip of eight superbright RGB LED lights that you can connect to the RBPi without wires, so it is an easy way to start. Blinkt! Has a female connector that matches the male GPIO connector on the RBPi, and that allows the tiny LED board to sit atop the RBPi. The RBPi can individually control each of the eight APA102 RGB LEDs on the Read more [...]

Connect with a New Type of Li-Fi

Many of us are stuck with slow Wi-Fi, and eagerly waiting for light-based communications to be commercialized, as Li-Fi promises to be more than 100 times faster than the Wi-Fi connections we use today. As advertised so far, most Li-Fi systems depend on the LED bulb to transmit data using visible light. However, this implies limitations on the technology being applied to systems working outside the lab. Therefore, researchers are now using a different type of Li-Fi using infrared light instead. Read more [...]

OLED Lighting in the Auto Industry

In recent years, a number of industries have started using Organic Light-Emitting Diodes (OLEDs) in diverse ways. The automotive industry, in particular, has seen a huge potential in OLEDs. For instance, very soon Audi will be coming up with OLED taillights. At present Audi has presented prototypes of the taillights. At the LOPEC Congress, Audi provides advanced insights into the needs of the automotive industry that the deployment of OLEDs will require to meet, and the future of automotive lighting. So Read more [...]

What is a QLED?

Recently, Samsung has announced their new TV technology using QLEDs to counter the OLED TVs that LG and others have put on the market. QLED stands for Quantum dot LED, and though Samsung has been using the concept of quantum dots in its TVs for quite some years now, they claim they will be bringing out several flavors of the QLED technology. According to Samsung, QLEDs are transmissive, as LCDs are, and light goes through several layers to create an image on the surface of the screen. The company Read more [...]

Multicolored LEDs Create Secondary Colors

Any student of physics knows mixing two primary color light sources produces a secondary color. For instance, mixing the primary colors red and green creates the secondary color yellow. There are three primary colors—Red, Blue, and Green. This process is easily seen in tricolor and RGB LEDs. There is a disadvantage in this method. As two primary colors are necessary for generating a secondary color, two LEDs must remain turned on at the same time. Therefore, generating a secondary color means Read more [...]

Dual Function LEDs & Multifunctional Displays

At the University of Illinois at Urbana-Champaign, researchers have made dual-function nanorod LEDs that could double as multifunctional displays. The researchers are also working with Dow Electronic Materials in Marlborough, Massachusetts. The LEDs are made of tiny nanorods arrayed in a thin film. They could enable new interactive functions and multitasking devices. The researchers report their advances in the February issue of the journal Science. According to Moonsub Shim, Professor of materials Read more [...]