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  • 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.
    by encom
  • Love the dude. Met him in line of a Chris Hadfield/smarterEveryDay talk. Absolutely fan-boyed haha. Super nice in person too
    by MostlyFragile
  • Built an atari punk console using these with my late father. Still have it hanging on my wall in a shadow box.
    by tuvix
  • 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.
    by swed420
  • Evil Mad Scientist makes a giant, discrete version as a soldering kit:

    https://shop.evilmadscientist.com/productsmenu/tinykitlist/6...

    Very cool. (Looks like it uses 26 transistors. I assume the die is similar.)

    by JKCalhoun
  • I believe they based the design off of the reference schematic from a datasheet of one of the popular 555 timers, but I don't remember which one.
    by jedimastert
  • Oh god I feel old. I remember being an excited schoolboy thinking how magic this was when it debuted.
    by davidwritesbugs
  • For me that is blue leds.
    by Brian_K_White
  • 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.
    by davidwritesbugs
  • 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 :(
    by darrinm
  • Yea, definitely don’t let out the magic smoke. That stops all the fun right away.
    by drob518
  • I have read as well that the 555 was used in the game paddles for the Apple II. 555 + potentiometer (the part you turned) varied the length (duty cycle?) of a square wave which the Apple II used to determine the paddle position.
    by JKCalhoun
  • There was a 556 on the Apple ][ disk controller (a dual 555).

    See: https://mirrors.apple2.org.za/Apple%20II%20Documentation%20P...

    by fortran77
  • 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!
    by stackghost
  • The 555 timer is still the most popular chip that hobbyists add to their parts inventory (see rankings at https://partsbox.com/ecdb.html). I find this both interesting and curious — I'd say it has mostly nostalgic value at this point. Almost every practical problem today is better solved by something else. And yet it persists, I guess mostly because of beginner tutorials and first LED blinky circuits.

    One nice thing about the 555 is that at least it aged well and still is very usable in those beginner tutorials. Unlike for example the uA741 which no one should use.

    by jwr
  • > Almost every practical problem today is better solved by something else.

    I'm curious about this claim. It's certainly easier to just wire up a modern microcontroller, but is there a better option that involves no software and is likely to still work the same today as it did 50 years ago?

    by ocdtrekkie
  • You can learn about the origin of the 555 timer from its creator in his free book here: http://www.designinganalogchips.com/

    Fun fact: his original concept needed 9 pins and therefore was going be forced to have a 14 pin package. A late epiphany got it down to the 8 pin version we know today.

    by PhaseLockk
  • 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!
    by SoleilAbsolu
  • Also consider the IC Timer Cookbook by Walter G. Jung.
    by jshprentz
  • The Mims books are fantastic. As a kid I collected every mini notebook and the green Radio Shack "Getting Started in Electronics." They were my intro to electronics along with the Radio Shack kits.
    by MisterTea
  • I have a paper copy of "IC 555 projects" kicking around on my bookshelf still!

    PDF version here https://worldradiohistory.com/UK/Bernards-And-Babani/Babani/...

    by stevekemp
  • Big Clive is currently livestreaming to celebrate the 555's birthday: https://www.youtube.com/watch?v=jzNjFJdaw_I
    by longwave
  • 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.

    by 3form
  • otoh i.m surprised the accelerometer was already available since 1927. since microcontrollers only the hardcore eecs kids build pid controllers from opamps for fun (only do hn on phone hard to link to that maker article of a fully analog segway where the writer missed the "analog" part and was like WOW a self balancing 2 wheeler by a grad student and not another baby's first Arduino bday kit
    by mrsvanwinkle
  • my favorite use of a 555 is in a solar charge controller. It is a voltage controlled switch!

    i have the page archived, but it's called A New Solar _ Wind Charge Controller Based on the 555 Chip (2_7_2026 12

    I can upload the webrip if anyone wants it

    by genewitch
  • Two videos tomorrow at 5:56!
    by FarmerPotato
  • I remember reading somewhere that it's the highest-selling IC of all time, which is a little surprising! I'd have guessed the winner would be an op-amp of some kind.

    555s are such delightful little guys. I used a pair of them, plus an ebay telephone line driver, to make an old telephone ring: https://hardfault.life/p/telco-2

    One timer runs at the ~20Hz ring frequency, and the other runs at ~0.2Hz on a 20% duty cycle. The slow one's output feeds the enable line of the fast one, so you get 1-second burts of ringing, then a few seconds of silence, then ringing... just like a normal phone.

    I moved about 5 months ago and haven't had time to get back to this project. The goal is to build a little phone company in a box, so I can have all my old PCs talk to each other with their modems.

    by ryukoposting
  • I learned (long ago) it’s trivial to fool my satellite receiver’s modem’s dial tone verification for remote pay per view ordering (it doesn’t phone home right away but gets angry if it’s not connected to a phone line).

    Turns one a single frequency that’s remotely close to one of the two tones of a dial tone will convince it. Wasn’t sine wave either but not a problem! 555 powered by a 9V battery.

    by Scoundreller
  • The trick is that it's sold as a timer but it's really a kit of parts from which you happen to be able to build a timer.

    There's a lesson in there somewhere.

    by regularfry
  • A couple of years ago I used a 555 in an attempt to fix a problem I had with my Xiegu G90 ham radio. When sending CW (morse code), the radio would sometimes not see a "dit" (the short tone in morse code). I could reproduce it by tapping the paddle too quickly. My theory is that the G90 doesn't use interrupts to detect paddle presses, but rather polls those lines, and sometimes misses when a pulse happens completely in between polls. I made a little circuit using a 555, where the dit side triggers the 555 and closes the dit line just long enough to always be picked up by the G90, but short enough to never cause two dits (at least not at the speed I was going at). I didn't bother doing the same for the dah side, because apparently my index finger is slower than my thumb and the problem never came up there. It worked flawlessly, but only when not transmitting. As soon as RF got involved, it behaved weirdly. I tried adding ferrite beads, but it didn't solve it. In the end I never used it, and just learned to not slap the dits so fast, but it was a fun experience and see the 555 work.

    More details: https://www.reddit.com/r/amateurradio/comments/1eo9ki7/xiegy...

    by wkjagt