Make: Technology on Your Time Volume 10

The Biggest Little Chip

AN INTRODUCTION TO THE VERSATILE 555 TIMER.

By Charles Platt

Back in 1970, when barely half a dozen corporate seedlings had taken root in the fertile ground of Silicon Valley, a company named Signetics bought an idea from an engineer named Hans Camenzind. It wasn’t a breakthrough concept, just 23 transistors and a bunch of resistors that would function as a programmable timer. The timer would be versatile, stable, and simple, but these virtues paled in comparison with its primary selling point. Using the emerging technology of integrated circuits, Signetics could reproduce the whole thing on a silicon chip.

This entailed some handiwork. Camenzind spent weeks using a drafting table and a specially mounted X-Acto knife to ...