Meter clocks are interesting works of geeky art that display the time using analog panel meters driven by a microcontroller. They can be strikingly artistic – and are getting to be very popular. There are a lot of homebrew designs that use a microcontroller and some small digital-analog converters to produce a signal for a variety of meter types. I’m working on one myself, but in the mean time, there are a lot of other ideas out there!
Andy has built his clock using servo motors to position the needles instead of meter movements, effectively making his meters from the ground up. I could see some advantages to this approach (more accurate control), but just driving an appropriate meter directly is a bit less work.
Another very interesting example of a meter clock comes from Len Bayles at ChronWorks, sellers of interesting clock merchandise including scopes and nixie tubes in addition to meters. He uses three 1 mA scale meters in a cluster and some DACs to drive this unusual set of gauges for hours, minutes and seconds. The full write-up including source files and parts lists is available over at his dedicated site for the meter clock, Meterclock.com.
These gauges draw more power (1 mA full scale) than the microcontroller or DAC alone could drive, so they are powered by a small amplifier to make sure they can move accurately.
There’s also the classic meter clock featured on Embedds.com using some seriously powerful meters – 50 mA full scale. In contrast, the meters I’m working on to build my small meter clock are 50-150 μA, about a thousand times more sensitive. These are mounted on a panel and it looks like a piece of test equipment or a rack mounted indicator display – interesting and industrial.
Another entry from Hack a Day shows off this elegant and incredibly wide arc meter “Clock for Geeks“, using a single face with a large area to allow it to display the time using a single servo-driven movement. A little big for my tastes, but very interesting!
from Chrass Landing comes the Anachronistic Chronometer. This one features some very stylish antique meters in the mA full scale range, one originally an ammeter and the others volt meters that can be driven the same way. The only unfortunate thing about it is he ruined an early 1920s vacuum tube radio to build this one:
“Meanwhile, I was checking Ebay for something steampunk-ish to put my clock into. Eventually I got the idea of using an antique radio. Not exactly steampunk, but the idea of an anachronistic “clock radio” seemed pretty funny to me. I settled on a home made 1920’s radio.” I think that radio was a kit radio from the 1920s, probably not an entirely homebrew one. But, whatever it was, he had the right idea with the meter placement. There were originally already viewing holes behind where those meters were mounted to let you look in at the tubes and see how brightly they glowed (and adjust their power using the knobs right below where the meters are now.) If left intact, that radio probably would have been worth a couple hundred dollars as-found or considerably more working.
But it does make a pretty neat clock.
Finally, one of the first meter clocks I discovered was several years ago, the original Chronulator. A kit you can piece together with μA-scale meters, I’m using it as the base of my clock project. Other people have made beautiful examples of Chronulators too, including this fine Steampunk Chronulator example made by a French designer:
As well as other craziness made from the same kit:
I wonder how long the Bombulator was left sitting by that planter. It looks like it could really attract some attention.