Bodet Flip Clock Rebuild

In institutions like schools or factories, it can be important to have an “official” time throughout the facility. This allows everyone to know, for example, when to take lunch, or to actually start a job. While systems like NTP and GPS make such a concept fairly trivial today, another way to synchronize clocks is to have a centralized timekeeping device telling displays throughout the facility when to advance. One might consider such a setup to be analogous to a number of dumb computer terminals, which link up to a single system for computing power.

iSax got ahold of a Bodet branded factory-style flip clock, which reveals the time, day of the week, date, and month, without any actual timekeeping mechanism onboard. It’s simply fed 12, 24, or 48V by a centralized system every minute (alternating between + and -) to cause it to tick forward with a nice audible feedback. Instead of central clock, he subbed in an Arduino Nano, along with an H-bridge circuit to take care of the actual pulses. No RTC is shown in the video below, but presumably one could be added to keep things on track.

Lack of timekeeping aside, these clocks aren’t quite as dumb as they might seem. Inside is a clever electromechanical wheel-based system that actually allows it to account for months that have less than 31 days, and even leap years. This functionality is powered by a separate DC motor, supplied here by a voltage regulator on the custom circuit board. The build looks like a fun reuse of old tech. Perhaps it can be used to know when it’s time for a solo on iSax’s “RoboTrombo” machine.