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8-Cent LM555 Timers — Parallax Forums

8-Cent LM555 Timers

50 pcs for $3.99 shipped! https://www.amazon.com/gp/product/B00CL7IV7E

Per https://en.wikipedia.org/wiki/555_timer_IC, it's the most popular IC ever; As of 2003, it was estimated that 1 billion units are manufactured every year. Suck it, McDonalds!

Invented in 1971, 45 years ago! When analog was all the rage. As an homage we should be making more 555 projects. Heck at that price, even making necklaces and paving our driveways with them.

Anyone remember Parallax's line follower contest back in 2012? :)



And this balance bot!



See also https://www.youtube.com/results?search_query=robot+555+timer



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Comments

  • Heater.Heater. Posts: 21,230
    Ha the wonderful magic of the 555. Combines everything you ever need into a simple dirt cheap package:

    1) Computation - with those comparators.

    2) Memory - with the flip flop.

    3) Timing - with the addition of a capacitor.

    4) Interfacing - It's output can drive significant power into loads. 200ma.

    There is nothing that cannot be done with the 555.
  • TorTor Posts: 2,010
    edited 2016-11-11 07:21
    And still.. I have problems finding a real need for them. I probably made an oscillator from one when I was a teenager, but nothing since. I'm itching to find a use for lots of them, as I can get 50 x NE555 for a bit more than a dollar on epay, or 100 if lucky with a bid (didn't bid yet)
  • Heater.Heater. Posts: 21,230
    Some crazy guy has built an entire CPU out of 555's !

    I built a switched mode boost converter from a 555 once.

  • I have a traffic light project sitting on the bench waiting to be built. 10mm red, yellow and green LEDs, run by two 555s or one 556. One of the first ICs I ever played with. Make noise, do timing, light some lights with a 4017 and a 555 oscillator. One of my favfavorites.
    2048 x 1152 - 769K
  • Tracy AllenTracy Allen Posts: 6,656
    edited 2016-11-11 19:45
    Chapter 11 of Hans Camenzind's book Designing Analog Chips (2005) describes how he developed the '555. "The project almost didn't get off the ground; the engineering staff didn't think much of the idea. Timers at the time were put together from an op-amp or comparator and a few discrete components... They argued that such a design would cut into the sales of their present ICs... It was a one-year contract and designing the circuit took half of that. No computer analysis then..." He goes on to describe the conundrum of needing 9 pins and how it hit him when driving home from work how to fit it into 8 pins, a U-turn back to try it. "The market reaction to the 555 timer was truly amazing. Art Fury made history by bringing out the circuit at an unprecedented low price, 75 cents. I had deliberately made the design flexible, but nine out of ten applications were in areas and ways I had never contemplated."

    Indeed. But 2 cents? The book is well worth the $15 if you're into analog and mixed signal.

  • Heater.Heater. Posts: 21,230
    Thanks for the head up on that book Tracy. Looks like something to nerd out to late into the winter nights. Even if I'm never going to design anything analog.
  • ercoerco Posts: 20,244
    Indeed. But 2 cents? The book is well worth the $15 if you're into analog and mixed signal.

    Sold! I just ordered the book and anything else Guru Tracy recommends. Thanks for that background info, I'm sure the book will be an interesting read. I'm starting to get interested in BEAM robotics and analog circuitry.

  • ercoerco Posts: 20,244
    I see Hans' book is also available as a legal free download!

    http://www.designinganalogchips.com/
  • Heater. wrote: »
    Thanks for the head up on that book Tracy. Looks like something to nerd out to late into the winter nights. Even if I'm never going to design anything analog.

    The world is analog. Digital is simply a choice to drive every transistor into saturation.
  • hatallica wrote:
    The world is analog. Digital is simply a choice to drive every transistor into saturation.
    Exactly. As digital designers, we must never forget that the devices we use are analog at heart. Things like rise/fall time and input/drive impedances are all analog concepts. To ignore them is to court disaster.

    -Phil
  • Heater.Heater. Posts: 21,230
    edited 2016-11-12 04:16
    Quite so. In fact somewhere around here you could probably find me quoting someone who said "There is no such thing as digital electronics". Was that Bob Pease or Jim Williams or..?

    I learned this the hard way. One of the first big projects I was hired to work on was pretty unreliable. Turned out to be mostly due to ridiculously long and sloppy board interconnects and poor board layout rather than logic or software errors. Took me a while to figure out what to do about it. That was with just the slow old "digital" of the early 1980's

    It's good to know what those electrons are up to in your circuit, and those pesky EM fields that get everywhere!

  • Heater, that sounds like Bob Pease. Here's a version of it from 1997:
    http://electronicdesign.com/boards/bobs-mailbox-24

    I live in the area but never got to meet Pease or Williams. The Computer History Museum displayed Williams' desk for a few months after he died:
    http://www.computerhistory.org/atchm/an-analog-life-remembering-jim-williams/
  • kwinnkwinn Posts: 8,697
    Jeff Haas wrote: »
    Heater, that sounds like Bob Pease. Here's a version of it from 1997:
    http://electronicdesign.com/boards/bobs-mailbox-24

    I live in the area but never got to meet Pease or Williams. The Computer History Museum displayed Williams' desk for a few months after he died:
    http://www.computerhistory.org/atchm/an-analog-life-remembering-jim-williams/

    Both are interesting reading, thanks for posting the links.

    A typo in the Jim Williams article did provide a chuckle "These real world sensations are called anal og signals" and also pointed out the need for a good proofreading software package. While simple spelling errors have almost disappeared other errors have more than made up for their loss. At times that leaves me wondering if my interpretation of what the author was trying to say is right.
  • Digital is simply a choice to drive every transistor into saturation.

    But a designer of digital soon learns the analog fact of bipolar transistors, that they are slow when driven into saturation, those pesky electrons like to stick around. Pile on a schottky diode or an additional transistor or two to achieve speed.

    A thing I like about Camenzind's book is that after he describes the original '555, he goes on to pick at what is wrong with it and looks at a couple of improvements in terms of the many parameters that define its analog performance. Also he breaks down the cmos version, strengths and weaknesses.

    I use the cmos LMC555 in circuits to measure AC conductivity. I always specify the LMC555 over alternatives such as the TLC555, because I've tried the others and know they don't work as well. Internal circuit and process variations no doubt. It makes me wonder how many versions are out there of the venerable bipolar '555, new and improved. Have to read those analog specs!

    Most academic texts start with a bunch of theory and occasionally look up at an example. Camenzind starts with historical context to motivate a full example, then deconstructs back to the theory as to how well it meets the goals. The theory part can be daunting if you are not up on monolithic transistor characteristics, but the context in itself is telling.

  • Tor wrote: »
    And still.. I have problems finding a real need for them. I probably made an oscillator from one when I was a teenager, but nothing since. I'm itching to find a use for lots of them, as I can get 50 x NE555 for a bit more than a dollar on epay, or 100 if lucky with a bid (didn't bid yet)

    My favorite use, lately, has been as gate drivers for MOSFETs and IGBTs. They're easily driven by 3v3 chips like the Prop.

    http://electronicdesign.com/power/lm555-makes-inexpensive-power-driver

    (For some reason this use annoys a few people. Obviously they don't replace the UCC37321 in Steve Ward's DRSSTC-2 (duh!), and I do own other gate driver ICs. But for the vast majority of MOSFET projects here, they work just fine. )

  • That's brilliant! Where else can you find a MOSFET gate drive for eight cents? Micrel? Nope.

    -Phil
  • erco wrote: »
    I see Hans' book is also available as a legal free download!

    http://www.designinganalogchips.com/
    Thanks for that Erco,I grew up in an analog world so I am finding it an interesting read.
    Jim

  • ercoerco Posts: 20,244
    RS_Jim wrote: »
    Thanks for that Erco,I grew up in an analog world so I am finding it an interesting read.
    Jim

    We are all growing up (old!) in an analog universe.

    I'm proud to say I built three IR beacons yesterday with LM555 timers. 24 cents well spent.

    I just realized in my OP when I suggested using them everywhere, "even making necklaces", that I had probably lifted that thought subconsciously from a favorite book, "A Canticle for Liebowitz". In a(nother) post-apocalyptic setting when all technical knowledge is gone and people are simpletons, a monk finds an unscavenged fallout shelter and some boxes of erco-style electronic parts:

    Minutes later, seated on a cracked foundation slab, he began removing the tidbits of metal and glass that filled the trays. Most of them were small tubular things with a wire whisker at each end of each tube. These, he had seen before. The abbey's small museum had a few of them, of various size, shape and color. Once he had seen a shaman of the hill-pagan people wearing a string of them as a ceremonial necklace. The hill people thought of them as "parts of the body of the god"--of the fabled Machina analytica, hailed as the wisest of their gods. By swallowing one of them, a shaman could acquire "Infallibility," they said. He certainly acquired Indisputability that way, among his own people--unless he swallowed one of the poison kind. The similar tidbits in the museum were connected together too--not in the form of a necklace, but as a complex and rather disorderly maze in the bottom of a small metal box, exhibited as: "Radio Chassis: Application Uncertain."



  • That's brilliant! Where else can you find a MOSFET gate drive for eight cents? Micrel? Nope.
    One of the aspects of the 555 in this application that delighted me was how well it can accommodate a 1.8V or 3.3V signal input despite a 12 or 15 Volt Vcc.

  • ercoerco Posts: 20,244
    edited 2016-11-14 16:38
    And as Heater already mentioned, the 555's output current capability of 200mA is an order of magnitude greater than most micros can deliver. That's why I like 'em for IR beacons, just hook them directly to an IR LED, which needs 60-100 mA for my evil purposes.

    Driver transistors are for suckers.
  • RS_Jim wrote: »
    erco wrote: »
    I see Hans' book is also available as a legal free download!

    http://www.designinganalogchips.com/
    Thanks for that Erco,I grew up in an analog world so I am finding it an interesting read.
    Jim

    You gotta love Camenzind's historical approach to the subject.

  • Heater.Heater. Posts: 21,230
    edited 2016-11-14 18:44
    erco,
    ...By swallowing one of them, a shaman could acquire "Infallibility,"...
    Wow, if that is what you get from munching on tubes imagine what magical powers one could get from eating Propellers or Intel processors!

    Reminds me of the time, in a former life, when my girl friend, who was totally non-technical, came with me to the first Maplin electronics store. I was amazed that she was ordering resistors by value. She had no idea what a resistor was but she wanted to make ear rings out of them. So getting the right colours was important!

    It all went well I guess, after five years with me she changed track totally, went off to get a degree in mathematics and was last heard of working a software engineer in Germany.

    Moral of the story: Never teach your girl friends anything technical. They may prove to be better at it than you are and float away.


  • ercoerco Posts: 20,244
    edited 2016-11-14 18:38
    Old meets new: Here's a tiny DIY LM555 board which mostly uses SMT components to sequence 10 LEDs. Brush up on your SMT soldering skills for a buck.

    http://www.ebay.com/itm/DIY-Kit-NE555-CD4017-Light-Water-Flowing-Light-LED-Module-/162141836942



    You can also brush up on your Russian.

  • Heater.Heater. Posts: 21,230
    That is the weirdest looking soldering iron I have ever seen.

    Still, gets the job done.
  • The Russian sure was enthusiastic about his Chinese electronic delivery's. The LED chaser should have been able to count down too, KIT car scanner effect.
  • ercoerco Posts: 20,244
    I've used THREE 555 timers in robot projects this week.

    I win beer nuts.
  • Heater.Heater. Posts: 21,230
    Seems to me, that with it's analog comparators, memory and digital output we could have built neural networks and artificial intelligence out of 555's decades ago.

  • erco wrote: »
    I just realized in my OP when I suggested using them everywhere, "even making necklaces", that I had probably lifted that thought subconsciously from a favorite book, "A Canticle for Liebowitz". In a(nother) post-apocalyptic setting when all technical knowledge is gone and people are simpletons, a monk finds an unscavenged fallout shelter and some boxes of erco-style electronic parts:

    Minutes later, seated on a cracked foundation slab, he began removing the tidbits of metal and glass that filled the trays. Most of them were small tubular things with a wire whisker at each end of each tube. These, he had seen before. The abbey's small museum had a few of them, of various size, shape and color. Once he had seen a shaman of the hill-pagan people wearing a string of them as a ceremonial necklace. The hill people thought of them as "parts of the body of the god"--of the fabled Machina analytica, hailed as the wisest of their gods. By swallowing one of them, a shaman could acquire "Infallibility," they said. He certainly acquired Indisputability that way, among his own people--unless he swallowed one of the poison kind. The similar tidbits in the museum were connected together too--not in the form of a necklace, but as a complex and rather disorderly maze in the bottom of a small metal box, exhibited as: "Radio Chassis: Application Uncertain."

    Hey, I'm in the middle of reading A Canticle for Leibowitz now myself! I'm really enjoying it!
  • ercoerco Posts: 20,244
    Now you're barkin', Electrodude.

    Want a smokin' deal on a signed first edition? https://www.abebooks.com/servlet/BookDetailsPL?bi=596719922

    NPR's 15-part radio play is awesome listening for a long drive.
    http://www.oldtimeradiodownloads.com/sci-fi/a-canticle-for-liebowitz
  • ercoerco Posts: 20,244
    A 555-based robot kit which apparently is of shoddy quality and sullies Banggood's good name. I tried to order one for a shot at robo-redemption but sadly it's sold out.

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