Comment by ofalkaed

Comment by ofalkaed a day ago

5 replies

The article bringing up flip-flop clocks reminded me of another mechanical digital clock that I can not quite remember the name of. It was from roughly the same time period as the flip-flop alarm/radio clocks but the numbers were wire grids or cutouts in wire grids and as the numbers changed they sort of faded from one digit to the next. I can't quite remember how the mechanism worked and the only clock of this sort I have ever seen was the one I bought ~20 years ago just to take apart and see how it worked. Anyone know what I am talking about?

The mechanism was surprisingly simple once I got it opened and saw how it worked but from the outside made no sense, I probably stared at that clock for an hour trying to figure out how it worked before I finally opened it up to see what was inside. I might still have the clock mechanism in a box out in the garage.

Edit: I suspect these clocks were actually from the time period at the end of flip-flops, showed up too late to become common, LEDs/LCDs killed them. The digits were on the dim side, perfectly fine for a bedside alarm clock and quite good for that situation but you had to be fairly close to clock to read it in a well lit room. Better than a flip-flop in a dark room but worse than an LCD in the light.

asdefghyk a day ago
  • ofalkaed a day ago

    The brightness of the clock was about the same as a tired old VFD that has consumed most of its phosphor but this was something much simpler and something anyone could figure out how it worked once they saw the insides. The general look was closer to the nixie tubes the other commenter mentioned but these grids did not emit the light, the light source was a standard bayonet base bulb or two behind the mechanism. I think the smoked plastic on the front was also part of how it worked, it acted as a filter and without it you saw everything but the numbers you wanted to see.

    Might have to go dig into that box in the garage and see if I still have it. I had intended on making a stand alone clock from it; the radio is not very good and the case has seen better days, so I was going to make a case for just the clock mechanism, perhaps its time.

    • estimator7292 a day ago

      There are projection-type digit displays. I can't seem to find a picture at the moment, but these had an array of incandescent bulbs which project the image of the digit onto an internal screen. The timeline seems about right, this was peak Apollo era tech.

      There's also nixie and numitron tubes, as well as some neon digit displays. If it wasn't a tube, maybe it was a nixie-like display with a stack of acrylic plates each illuminated by an individual bulb.

kalleboo a day ago

Nixie tubes worked as you describe but with the glowing elements inside a gas-filled glass bulb