Circuits & Schematics - Light - 8

The Design Idea in Figure 1 is a precision current mirror used to drive two strings of five white LEDs. Figure 1. Current source/mirror driving two LED strings. The op-amp has double negative feedback (since M2 inverts the signal at the ...

General information In this article we will talk about a simple device that I designed for automatic control of additional LED lighting in the kitchen. Kitchen renovating and complete replacement of kitchen cabinetry are main reasons for ...

Matthew Grant, Linear Technology Design Note 556 Introduction The LT®3952 monolithic LED driver includes a 4 A, 60 V DMOS power switch, excellent for driving high current LEDs in buck mode. Among its many features is an input current sense ...

SK Kaul and IK Kaul EDN The absence of a fast one-shot multivibrator in the entire TTL family, as well as the low-voltage swing and unwieldy supply requirements of ECL, drove us to exploit the fast transition times and low propagation delays of ...

A basic combination of a photovoltaic panel, multiple LEDs, and a small dc-dc regulator can provide light in dark corners while also offering a modest auxiliary dc-power rail. A solar-powered, daytime-only lamp without a battery for energy storage ...

Design Note 548 Synchronous buck-boost converters with four power switches can deliver very high efficiency while providing both step-up and step-down DC/DC conversion. Combining the capabilities of two separate converters (buck and boost) has the ...

Ambient light is increasingly being used as a source of energy. To help designers of such systems, this circuit accurately measures ambient light intensity over four decades of measurement. The design is highly cost effective and, with the sensor ...

Bjoy Santos EDN Regardless of its color, an LED's light output varies as a function of forward current and ambient temperature. As Figure 1 shows, an LED's light output can vary by as much as 150% over its operating-current range. In response, a ...

Design Note 445 Introduction Once relegated to the hinterlands of low cost indicator lights, the LED is again in the spotlight of the lighting world. LED lighting is now ubiquitous, from car headlights to USB-powered lava lamps. Car headlights ...

The white-LED flasher in Figure 1 offers an alternative approach to a previously published idea ( Reference 1 ). Targeting use in portable appliances and products powered by a single cell, this circuit flashes an LED to provide a highly visible ...