I loved reading Windell Oskay’s Zener diode tutorial. It’s fascinating stuff and Windell describes the technology in his usual easy-to-understand style. Check it out!
Zener diodes are a special type of semiconductor diode– devices that allow current to flow in one direction only –that also allow current to flow in the opposite direction, but only when exposed to enough voltage. And while that sounds a bit esoteric, they’re actually among the handiest components ever to cross an engineer’s bench, providing great solutions to a number of common needs in circuit design.