Circuits & Schematics - Light - 6

This Design Idea circuit regulates the current through one or more LEDs, making it almost independent of supply voltage. Its main advantage is a very small dropout voltage, which can be less than 100 mV. The design could find use on LED strips, ...

The circuit in Figure 1 represents a simple and inexpensive way to provide additional bicycling safety. A conventional bicycle-generator lighting system works with the circuit to provide safety lighting for several minutes after the bicycle has ...

Keeping low-voltage outdoor lights illuminated takes some effort. Bulbs burn out, and connections corrode. HB LEDs (high-brightness light-emitting diodes) seem like acceptable replacements, but most are available only in surface-mount packages, ...

High-power LEDs challenge electronics engineers to design accurate and efficient, yet simple, driver circuits. Conventionally, driving high-power strings with accurate current requires dedicated switching regulators. Choosing a discrete driver ...

Tom Gay EDN Most current microcontrollers offer I/O ports that can change their functions during program execution. As outputs, the circuits can sink and source reasonably large amounts of current. This Design Idea shows three alternative methods ...

Robert H. Russell Electronic Design I needed a simple LED indicator showing that a particular voltage level had been reached specifically, that a capacitor had charged to a particular potential. I was convinced that there must be a way that a ...

Sundaresan Sundararaj Electronic Design This idea describes a white-LED (WLED) driver circuit controlled by a simple ambient light sensor (ALS). A typical application would be a brightness control for cell-phone backlighting. On a very sunny day, ...

Stephan Goldstein, Analog Devices EDN The human eye's highly nonlinear response to light levels poses problems for designers of adjustable lighting. Simple hardware or software linear-control methods compress most of the apparent intensity ...

Al Dutcher EDN The circuit in Figure 1 allows you to light any type of LED from a single cell whose voltage ranges from 1 to 1.5 V. This range accommodates alkaline, carbon-zinc, NiCd, or NiMH single cells. The circuit's principal application ...

Jim Grant EDN A white LED delivers a wide color spectrum and better visibility than do monochromatic LEDs. However, a white LED presents a higher forward-voltage drop than do its colorful counterparts and thus poses problems for operation from a ...