IEE clock

The IEE clock looks somewhat un remarkable at first glance. Upon closer inspection though, you’ll find out that there are 12 light bulbs crammed in there for each digit. The bulbs sit behind a curved lens with the numerals on it. When the appropriate one is lit, it projects the number on the front of the clock. While it isn’t new, it is certainly new to us. It is also interesting that you set the time by rotating the little dial on the top right. While it may be easier to set the time that way, it seems that it would be prone to getting nudged on accident.

[via the Hackaday Flickr pool]


  1. That switch on the lower right is AWESOME! Custom?

  2. Tucker says:

    Haha, 4:20

  3. andjohn says:

    Wow, that looks amazing! I’d clean up the outer casing and it could look so classy. :)

  4. M4CGYV3R says:

    Excellent choice of time on the clock picture.

    Also the exploded view( seems to be down.

  5. Worker says:

    Some nuke plant would probably pay to get their hands on those old parts.

  6. Mark says:

    I have seen this method of display in a 70s era elevator I ride occasionally.

  7. IMMMM says:

    What? no mention of 420? how lame HAD.

  8. HackJack says:

    I wonder how long the light bulbs could last? The MTBF goes way down with that many bulbs.

  9. mess_maker says:


    There is a place near me that sells those for probably $4 – 5 each…

  10. anon says:


    “The MTBF goes way down with that many bulbs.”

    No it doesn’t. Bulb failures are independent events.

  11. anon says:

    i think he meant that the mtbf of the clock would go way down, as in how long would it run before one of the light bulbs would need replacing

  12. anon says:


    “i think he meant that the mtbf of the clock would go way down, as in how long would it run before one of the light bulbs would need replacing”

    No, we would expect the clock to be 100% operational for at least the MTBF of the worst lamp. Since lamp failures are statistically independent events, more lamps don’t mean the MTBF gets lower.

  13. CH says:

    The time you’d expect before having to change a bulb is 1-(1-X)^n where X is the chance of bulb failure, and n is the number of bulbs.

    Since 0 ≤ X ≤ 1, 1 ≥ 1-X ≥ 0, (1-X)^(a+1) ≤ (1-X)^a, 1-(1-X)^(a+1) ≥ 1-(1-X)^a

    So this increase as n does (if X isn’t 1 or 0).
    But I think MTBF which is ‘Mean Time Before Failure’ *is* X, and is a value independent of bulb quantity, but more dependent on bulb *quality*. It could be mistaken as meaning ‘Minutes Till Bulb Failure’ though, but that isn’t a ‘thing’.

  14. Frogz says:

    this would have been epic win if it was posted ON 4/20 as well
    [S]btw, why the bulbs as opposed to somthing the clock making industry discovered 30 years ago, LEDS[/S]
    just clicked the article i want 1!!!
    btw, in purposes like this im guessing the bulbs arnt being driven at full power so they will have ALOT better mtbf than you might expect

  15. Hirudinea says:

    Love it, so 60’s! (But replace the lightbulbs with LEDs)

  16. shiftybill says:

    420 we all know what that means…

  17. mick says:

    hell yeah beautiful work love the clean look
    smoked one down just for that, props

  18. Ganjika says:

    Happy 4.20 for last week! EEYYYOOO!

  19. Jesop says:

    He claims to have found the things at a flea market for $10. I don’t believe him; he bought them on eBay.

  20. rain says:

    make tv show lost clock ???

    that sound is from supermarket check out counter!!!

    good luck email me when you do….

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