This simple 4093-based audio peak detector from December 2004 monitors music and turns on a small light when the sound gets ...

This circuit uses two quad op-amps to form an eight LED audio level meter. The op-amp used in this particular circuit is the LM324. It is a popular IC and should be available from many parts stores.

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 ...

Evil Mad Scientist Labs brings us this easy to make LED blinking circuit. The idea is to put a LED in series with a small blinking incandescent bulb from a string of Christmas lights. The bulb has an ...