Reverse engineering Solari soft flap displays

This is a side view of the guts of a one character Solari soft flap module. This is the type of mechanical display used in some transportation hubs that have a flap for each letter. The motor turns the flaps through the alphabet until it gets to the target letter. Recently [Boz] had a client approach him who needed a custom controller for a 20-character soft flap display.

The process started out with a magnifying glass and multimeter which yielded a rather complicated hand-drawn schematic. An optical encoder is used to judge which character is currently displayed. After analyzing the output using an oscilloscope [Boz] designed a PIC based driver board which is controlling the display seen in the clip after the break.

The great thing about these displays is that they don’t use any electricity except when they change letters. This sounds like the predecessor of ePaper and makes us wonder if there are any companies developing high-contrast ePaper to replace soft-flap digits?

Comments

  1. hspsoftware says:

    Nice work!

    Always love seeing someone reverse engineering stuff…

    As of the thing with the companies doing high-contras ePaper…. I would REALLY miss that awesome flipping sound!!!

    • Ratix says:

      Some of the boards that used to use this type of displays often get a set of speakers & a circuit installed to “simulate” the sound of the real deal.
      And sometimes also the visual animation to boot.

  2. technodream says:

    oh i already gots something cooking for you in my workshop… you just wait a month or two.. or five.

  3. sdfsf says:

    Where do you get these for individual purchase? I haven’t been able to find the flip modules or the electromechanical dot matrix modules anywhere online.

    There are a few manufacturers, but they seem to only be business-to-business – or through integrators, who definitely aren’t interested in individual sales.

  4. boz says:

    Hi Guys

    Again sorry for the video, It and the pictures were filmed by the customer from his old phone once it was partially dismantled and after a few beers.

    It’s with the carpenter now, once its all back in a few weeks I promise I will get better pictures with all the flappers going – and some more appropriate wording :-[

  5. dext0rb says:

    I have always LOVED these types of displays. I’m not even sure why…

  6. xobmo says:

    Steampunk component?

  7. Stu says:

    Not heard that one, arent they called split flap displays?

    http://en.m.wikipedia.org/wiki/Split-flap_display

    Regardless, very cool! I’d love to try this out but they’re as rare as hens teeth. Impossible to be in the right place at the right time to acquire them second hand, at least in the UK.

  8. Rw says:

    I have wanted to build a retro 1970s styled home audio deck to display mp3 id3 tag information (file name, track number) for a long time. I suppose it could also pull information from hd radio signals.

    These types of displays’ style fit many retro projects better than Nixie tube, LCD, or VFDs.

    Just for fun, I’d like to see someone build a calculator using these

  9. Polytech says:

    These flap displays have always fascinated me ever since I was a little boy (and that was a VERY long time ago). I could sit and watch in an airport for hours (or so it seemed) how the info on the display is changing. It always reminded me of some kind of a roulette – until the entire text change is complete, you never quite know if your flight is on time or delayed. Those last moments before the flaps settle could be pretty intense when it’s already been delayed a few times…

    I am also wondering where people get these? These days it seems anything can make its way on ebay but I never came across these flap-display digits.

  10. Dave says:

    Now just make it look like the counter from LOST and we are buisness :)

  11. John U says:

    Not just zero-power when static but readable under almost any lighting condition & from wide angle.

    I do love these, very retro.

  12. rmds says:

    You can buy them from these guys but they require very large quantities, maybe someone can kickstart a lot purchased, or you can donate based on how many you want

    http://www.salient.com.au/products-splitflap.htm

  13. cgommel says:

    If you want to play with split-flap displays just go to this site. These are 30 split-flap letters and a clock in our office that can be controlled from anywhere.

    Because of the daylight only illumination the text will only be visible during german daylight (typical 6am to 4pm UTC)

  14. John says:

    I wondered do you know where Solari split flip display at? I am trying look find one. I know it’s hard to find it. Let me know Thanks.

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