Should have used a 555 - or 276 of them

When asked to whip up a simple hourglass, most of us could probably come up with a quick design based on the ubiquitous 555 timer. Add some passives around the little eight-pin DIP, put an LED on it to show when the time is up, and maybe even add a pot for variable time intervals if we're feeling fancy. Heck, many of us could do this from memory.

So why exactly did [Jesse Farrell] manage to do essentially the same thing using a whopping 276,555s? Easy — because why not? Originally started as an entry in the latest iteration of our 555 contest, [Jesse]'s goal was simple - build a working timer with a digital display using only 555s and the necessary passives. He ended up needing a few transistors and diodes to remove it, but that's a minor concession considering how many chips he replaced with 555s, including counters, decoders, multiplexers and display drivers. All of these chips were built from basic logic gates, a latch, and a flip-flop, all made from one or more 555s, or variants like the 556 or 558.

As you can imagine, 276 chips take up a lot of space, and it took eleven circuit boards to complete the timer. One main board serves as the timer control panel as well as the motherboard for ten other boards, each devoted to a different block of functions. Everything is neat and tidy, and very well executed, which is consistent with the excellent documentation [Jesse] produced. The whole thing is wonderfully, unnecessarily complex, and we couldn't be more delighted to present it.