EEVblog: The 555 Timer is 55 years old [video](www.youtube.com)
159 pointsby brudgers5 hours ago21 comments
  • 3form4 hours ago
    5:55 video released on May 5th, as per description :)

    For something feeling like a fairly specific IC, I remember seeing many projects that use it throughout the years in wacky ways - and seeing it makes me happy to know that the sentiment for this little piece is shared.

  • darrinm2 hours ago
    As a kid I didn’t understand what the 555 timer chip on the Apple II disk controller was doing but I learned the hard way that when you misalign the pins on the drive connector cable and the 555 chip releases its blue smoke you can’t use the drive anymore :(
  • longwave4 hours ago
    Big Clive is currently livestreaming to celebrate the 555's birthday: https://www.youtube.com/watch?v=jzNjFJdaw_I
  • SoleilAbsolu3 hours ago
    I still have the Forrest Mims III Radio Shack "555 Engineer's Mini-Notebook" somewhere in my basement. And rumor has it that Sammy Hagar can't drive 555 because his car just isn't fast enough!
  • davidwritesbugs4 hours ago
    Oh god I feel old. I remember being an excited schoolboy thinking how magic this was when it debuted.
    • davidwritesbugs4 hours ago
      I also remember being amazed, and did a forehead slap, when an old army bomb disposal man explained how, what I thought was an innocent device, was used by the IRA in bombs.
      • nickcw4 hours ago
        Ha. When I was a teenager I used to build 555s into timers for the same purpose using a no PCB rats nest construction.

        Though surprising the family at dinner with a small explosion was a much more innocent purpose.

    • Brian_K_White3 hours ago
      For me that is blue leds.
      • davidwritesbugs3 hours ago
        Yes! I remember thinking "damn you band gap physics, if we only had blue leds we could do colour displays with LEDs, but that can never happen."
  • mnw21caman hour ago
    I used one of these to win an inter-school science competition when I was ~13. It was a minute timer. The competition board doubted I had built it all myself, so they plonked it down in front of me and demanded I draw the circuit diagram in front of them.
    • jacquesm37 minutes ago
      That says a lot more about them than it did about you.
  • tuvix4 hours ago
    Built an atari punk console using these with my late father. Still have it hanging on my wall in a shadow box.
    • swed4204 hours ago
      I recently dug one out to use as a hardware shutdown timer to power off an rpi's PSU once it has presumably halted without having to resort to a dedicated MCU for the task.
  • nom4 hours ago
    also today's date is 5.5. and the video is 5m55s
  • sho_hn2 hours ago
    I have a Displate of a decapped 555 hanging near my EE workbench:

    https://displate.com/displate/2002057

  • OldSchool2 hours ago
    As an electronics-enthusiast kid in the 70's, just before home computers showed up at all, I wished the 555 was for Time Travel
  • pryelluw3 hours ago
    Back when radio shack still existed I would buy a 555 timer during every visit. I live collecting them and still have a bunch somewhere stored. I continue to do it with the 328p arduino boards as well whenever I visit my local microcenter.
  • stackghost2 hours ago
    When I was a camp counselor in my 20s I designed a one-octave "piano" out of one of these, a battery, paperclips for keys, and a shitload of resistors. We had the kids build them on proto board. They sounded harsh but you could play Mary Had a Little Lamb on them!
  • encom3 hours ago
    Can't watch it right now, but upvoted for Dave Jones. He's taught me so much. Absolute treasure, and the host of one of the last great active forums. Thank you for not blackholing all that info on the disaster that is Discord, like so many other communities.
  • Etoro20242 hours ago
    I used to get exited about this. Hahaha I think I miss those days.
  • amelius3 hours ago
    What component values do you need to time exactly 55 years?

    Maybe it could work if you used 5 timers?

    • ua7092 hours ago
      How exactly is exactly? Can I make it measure 1 hour with an allowed tolerance of 55 years, plus or minus. :)
    • megous2 hours ago
      I don't think you could do it. Not with the original BJT variant anyway. :)
      • floxyan hour ago
        Hmm, why not? For the astable configuration, you could use a 100F capacitor with R1 = 10 Meg and R2 = 7.5 Meg, for a 55 year period. Base current for the Threshold NPN will come from the Trigger PNP (and hopefully temperature drift matches OK). Other than maybe the 100F capacitor might have some variation in capacitance and leakage current over the course of 55 years ;-)

        https://www.digikey.com/en/products/detail/tecate-group/PBLH...

  • kazinator4 hours ago
    Time to slow it down to lower frequencies and give it more frequent checkups.
  • ilvez4 hours ago
    killer oneshot, laughed hard..
  • aj73 hours ago
    The late Harold DuBose use to use the 555 as a power inverter as it could sink 200ma at the laser companies he worked for. Convenient and cheap.
  • raverbashing2 hours ago
    Makes me wonder if we could have a 555 circuit with a trigger time of 55 yrs
    • mnw21caman hour ago
      How many capacitors do you have that can hold their charge for 55 years?
  • robofanatic4 hours ago
    and this is the fifth comment
  • jwran hour ago
    [dead]