Not All 7-Segment Displays Are Electronic

There are a variety of means by which numbers can be displayed from an electronic circuit, and probably the most ubiquitous remains the seven-segment display. Take seven LEDs, lamps, LCDs, VFD segments or mechanical flip-dot style units in the familiar rectangular figure eight, and your microcontroller or similar can display numbers. There are a variety of different interfaces, but at most all that is needed is a level shifter and a driver.

Sometimes though we encounter a completely novel 7-segment display, and such is the case with [Fhuable]’s all mechanical single digit display. It bears a superficial resemblance to a flipdot display, but instead of a magnetic actuator, it instead uses a complex system of gears and cams to flip the segments sequentially from the turning of a small crank. It appears to be the same mechanism he’s used in his subscription counter project whose video we’ve placed below the break, and it is truly a thing of beauty. We’re not entirely certain how useful it would be as a general-purpose display in its current form, however, we can see it being adapted with relative ease. A clock might, for example, be an eye-catching project.

Most displays that make it here have some electrical components, so it’s unusual to see an entirely mechanical one. But that’s not necessarily always the case.

Thanks [Mike Horne] for the tip.

23 thoughts on “Not All 7-Segment Displays Are Electronic

  1. Neat, but I am not sure of the advantages over a magnetically latched flip segment display.

    My totally hand driven large 7 segment display has been in regular weekly use, and out in the weather for over a year now with no issues. It works in the heat of the summer and the sub zero of the winter. I think the beauty is in the simplicity. There is almost nothing to go wrong. https://hackaday.io/project/161215-largemechanical-hand-activated-7-segment-display

    1. That’s what I thought of too. Peter’s version seems to be more compact but doesn’t include any motors in his project.
      I’m curious about friction in both designs because I think it would be interesting to see a mechanical 7 segment based clock using a mechanical movement.
      I like the idea of a pendulum clock with a 7 segment readout because of the juxtaposition of the whole thing.
      But could a mechanical movement be able to drive a chain of these mechanical displays?

    1. I had a mechanical clock like this back in the 80’s. Pretty cool to watch, and after a few months, I could wake up at whatever time I wanted without setting the alarm. Each digit change made a unique sound, and my brain knew what time it was, in my sleep.

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