An Enduring, Versatile Little Chip
By Jonathan Poet
I don't think much about the innards of my electronic gadgets. The components — the integrated circuits and such — might as well be magic beans. But the more I read about the 555 timer, the more awe-inspiring the little nugget becomes. Invented four decades ago by Hans Camenzind (and, amazingly, never patented), he estimates about 1 billion 555 chips are produced per year. You can buy one retail for about a quarter.
And what do you get for 25 cents?
If you know what you're doing, you get a versatile oscillator and timer that can be tuned very simply. People smarter than me turn them into buzzers, timers, alarms, metronomes, switches and lamp flashers. Some vintage personal computers used 555 variants for joystick controllers. One Instructable suggests the enterprising hobbyist could use one to simulate a heartbeat for a very realistic fake blood-squirting special effect.
Most people have encountered dozens of 555s in their lives and didn't even know they were there. Camenzind himself told the Transistor Museum for an oral history: "Several spacecraft have them. And, many, many toys. That’s the range."
Forrest M. Mims III wrote an entire book about the 555 and used a pair of them in what is now called the Atari Punk Console, arguably one of the world's simplest analog synths and a hoot of an electronics project for beginners. (There are kits. Go buy one, build it and then fight with your housemates about who gets to play with it.)
Forty years in, the little chip is still stoking the fires of inspiration. A couple of 555 fans recently unveiled a contest centered around it. The slogan: "You've got eight pins … and one shot." Awards will be given to electronics designers who use it in both artistic endeavors and utlitarian ones, and also for the most elegant designs and the most overly complicated ones. Judges will include Mims and Camenzind.
The contest stands to be a testament to this litle chip's enduring versatility. I can't wait to see the winners.