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If you love LEDs on computers I'm sure you wanted one of these.

Discussion in 'General Electronics Chat' started by blueroomelectronics, Aug 27, 2007.

  1. blueroomelectronics

    blueroomelectronics Well-Known Member

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    It's an old CM-5 from thinking machines. Thousands of LEDs for the thousands of tiny microprocessors. Blinking and flashing.
    [​IMG]
  2. ericgibbs

    ericgibbs Super Moderator Most Helpful Member

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    Hi Bill,

    But I want to display hexadecimal and will they work for 12 months from a 9v battery?:D
    Can you post the driver code, preferably written in Cobol and I need it by tomorrow:p

    Eric
  3. things

    things New Member

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    cool!! i wonder if once they all flashed to form a word:D
    could you please send me the circuit diagram also my email is ispamtoomuch@spammerland.com:D :D :D :D :D
  4. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Hi Eric,
    LEDs use a lot of power.
    A little PP3 9V alkaline battery has a very low amount of power and can light a single LED at 27mA for only about 32 hours, dimming all the time. After only 6 hours the 9V battery voltage is only 7V. After 20 hours the voltage is 6.2V and at 32 hours the voltage is 4V.

    One year has 8760 hours. A little PP3 alkaline battery can supply only 0.1mA for one year.
    An LED hex display with an average of 12 segments lighted at 10mA each uses 120mA.

    Use an LCD display. It uses a very low amount of power if it is not lighted.
  5. ericgibbs

    ericgibbs Super Moderator Most Helpful Member

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    hi agu,
    Thank you for taking the time to respond.

    I must apologise to you, I was making a joke reply for Bill's OP.
    Its back fired on me:eek:

    I owe you one!

    Regards
    Eric
  6. blueroomelectronics

    blueroomelectronics Well-Known Member

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    No soup for you.
  7. blueroomelectronics

    blueroomelectronics Well-Known Member

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    Now I could build it but it would be very very dim...

    LOL sadly someone will probably seriously reqest that.
    I like the posts that go... I have a 30W supply but I need 600W how do I build an adapter.
  8. justDIY

    justDIY Active Member

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    Hello Dear Sirs,

    Thank you and congradulations on your postings of many leds project. I am current graduating training at university and needing assist with final project. I wish to create many leds but free power from sun with wireless gsm. Please help, I need to submit proposal by this end of month.

    my email is sungradu@hotmails.com

    thanks you!

    just some humor guys, no need to reply :)
  9. blueroomelectronics

    blueroomelectronics Well-Known Member

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  10. ericgibbs

    ericgibbs Super Moderator Most Helpful Member

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    hi Bill,
    Never mind the soup, I've just eaten 'crow' for audioguru!:p

    Eric
  11. ericgibbs

    ericgibbs Super Moderator Most Helpful Member

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    Bill,
    Ive actually seen this working recently in SouthAfrica.

    Back in the UK during the 1930 and 1940's a guy would visit our neighbourhood about once a month and he used this exact setup,,, not joking.

    Sharpened knives, scissors and the like

    Eric
  12. JimB

    JimB Moderator Most Helpful Member

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    I have seen this setup in the UK, probably until the late 50s.
    A very practical solution.

    JimB
  13. blueroomelectronics

    blueroomelectronics Well-Known Member

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  14. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    It was commonplace all over Europe - bit before my time though! :p
  15. ThermalRunaway

    ThermalRunaway New Member

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    What do all those switches do?!?!

    Brian
  16. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Some people think that an amplifier can boost a 30W supply to an output of 600W.
    I think it would take a miracle to do that.
  17. blueroomelectronics

    blueroomelectronics Well-Known Member

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    Brace yourself, that's how you programmed it.
  18. things

    things New Member

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    its a built in keyboard:p :D :D :D or should i say switchboard?:D :D :D
  19. ericgibbs

    ericgibbs Super Moderator Most Helpful Member

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    hi,
    Even back then the UK was at the "cutting edge of technology":D

    Eric

    So as not to cause any confusion about the above statement,
    "cutting edge of technology",
    means the sharpening of cutting tools.:rolleyes:
  20. Hero999

    Hero999 Banned

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    Of course it's perfectly possible, he didn't say how big the 9V battery is or how many rooms in is house he has spare to cram with batteries.:D