Sometimes, you need an alarm that is both audible and visible in an application that's stingy with space, power, and budget. The circuit in Figure 1a is compact, efficient, and inexpensive. The F336HD ...

This slideshow is based on the LEDs Design Ideas Collection, a collection of LED-related reader submitted circuits and design applications that have appeared in EDN's 'Design Ideas' section. Here you ...

The flashing is thanks to LEDs with a built-in, integrated flashing circuit and the nasty noise comes from a piezoelectric buzzer — both are available from electronics stores that sell ordinary LEDs.

With cycling safety in mind, I bought a pair of low power red LED things that replace the bungs in the end of drop handlebars. They are a neat way to get a bit of extra visibility – and to give a ...