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Thread: Crosstimer v2

  1. #1
    Junior Member
    Join Date
    Jan 2014

    Crosstimer v2

    Some remember my old posting about building a 7 segemnt crosstimer.

    It's working fine since then, but now I'm thinking of building version 2.
    I had some issuses with the first led and the power, which I try to solve in this version.

    I don't have a power switch or something else. I always pull the plug.

    First of all this is the layout of the whole timer
    Click image for larger version. 

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    As you can see I have power at the bottom and data on top. The overall length is about 2m (79in).

    Each 7 segement is wired as followed
    Click image for larger version. 

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    More photos are in the old thread linked at top.

    My Ideas for Protection
    Click image for larger version. 

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    • To protect the LED strip from the data side I would use two Schottkydiodes with a small Uf = 0.1V on every segement
    • On the power side I would put a capacitor (1000uF or more) and a Zenerdiode (5.1V)
    • Also a capacitor on the 74HCT245

    More over I'm not using CAT6 cables for data. Should I consider running my data line twisted with a ground line?

    Thanks for your help and thoughts!

  2. #2
    Junior Member
    Join Date
    Jan 2014
    I tried it with the diode array. But had no luck.
    I used BAT 86 (Schottkydiode, 50 V, 0,2 A, DO-35).

    But I found an article on Adafruit, which states that there should be a data line resistor. So that's what I'm trying now. My diodes are plugable. So more testing :-)

    Attachment 15745

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