8-Cent LM555 Timers
erco
Posts: 20,256
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
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
Comments
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.
I built a switched mode boost converter from a 555 once.
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.
http://www.designinganalogchips.com/
The world is analog. Digital is simply a choice to drive every transistor into saturation.
-Phil
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!
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.
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.
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. )
-Phil
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."
Driver transistors are for suckers.
You gotta love Camenzind's historical approach to the subject.
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.
http://www.ebay.com/itm/DIY-Kit-NE555-CD4017-Light-Water-Flowing-Light-LED-Module-/162141836942
You can also brush up on your Russian.
Still, gets the job done.
I win beer nuts.
Hey, I'm in the middle of reading A Canticle for Leibowitz now myself! I'm really enjoying it!
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