Circuits & Schematics - Light - 4

LED-driver circuits can be dimmed by applying a variable duty cycle (pulse-width modulation, or PWM) to the LED. PWM exploits LED behavior: At higher current levels, the LED’s light output is higher for a given level of power dissipation ...

This Design Idea describes a single white-LED torch, which can be housed in an empty glue-stick tube and has a long rechargeable-battery life. The circuit is constructed with just a few commonly available parts. This torch has proven to be highly ...

Christian Rausch EDN Designers use ballast ICs, such as International Rectifier’s IR53HD420 , in CFLs (compact fluorescent lamps) for heating the filaments, igniting the lamps, and supplying the lamps with current. Manufacturers produce these ...

TA Babu EDN LED technology is opening the door to a variety of high-power-illumination applications. The circuit in Figure 1 can let you know when ac power is available. To drive a power LED from the ac line requires a converter or a similar ...

Controlling the brightness of LEDs requires a driver that provides a constant, regulated current. To achieve this goal, the driver topology must be able to generate a large enough output voltage to forward bias the LEDs. So, what are your choices ...

Ajmal Godil Electronic Design Consumer-based LED applications have really taken off. You now find them in home lighting, airplane cabin lights, automobile lights, MP3 players, and elsewhere. In the past, most LED drivers were based on some sort of ...

A solar day lamp is a simple, inexpensive device for bringing “daylight” to dark interior spaces whenever the sun is shining. This article provides complete instructions for designing lamps using both passive and active current limiting ...

Grant Smith EDN Powering 20 to 30 white LEDs from three alkaline cells presents an interesting problem for the conventional boost converter. The required boost ratio and duty factor are simply impractical. If you are determined to design with ...

Kyle Lawrence, Analog Devices Design Note 570 Introduction The LED backlights in automotive heads-up displays, infotainment systems, and dashboard lighting must be bright enough to compete with direct sunlight streaming into a car during the day, ...

Using LEDs has gained popularity as a method of saving power for general-purpose lighting, but an efficient method for driving them has also become a necessity. For example, Lumileds' Luxeon devices create lighting effects or room lighting. ...