555 Timers — The Basics

What even mildly-seasoned electronics geek has not used or at least heard of the 555 timer?

Few, as 555 timers have been around since the early 1970’s.

The timers are great for creating pulses of varying widths, among other things.

Why not use a microcontroller instead?

For one thing using an Arduino or a PIC just to create pulses is like killing a mouse with a hand grenade. It works, but it’s an extreme over-kill.

Second comes cost. I talked about the cost of some popular “trainers” like the Arduino in my post about working directly with microcontrollers vs trainers. A 555 timer can be purchased for about $0.35 in quantities of one. Buy more and the price drops.

Things like PICs and trainer boards are not only more complex to work with, they take up more real estate and power than a tiny 555 chip.

There is a myriad of other uses for the timers including switch debouncing, tone generators, triangular waveform generators, a voltage controlled oscillator and more. In fact, people are still coming up with new used for these ICs to this day.