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Giant 555 Timer

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Re: Giant 555 Timer

#21

Post by logbiscuitswave »

2sk21 wrote: post #3

What a great project Idea! I have often looked at the internal schematic of the 555 and wondered if it could be made with discrete components - now I know that it is possible :-)

If you want something in kit form, I’m a big fan of this: https://shop.evilmadscientist.com/productsmenu/652

It’s a beautiful representation of a 555 timer in discrete component form - and functional too.

The 555 timer itself is a pretty simple IC since it’s just a few dozen transistors and resistors at its core.

Re: Giant 555 Timer

#22

Post by ncmncm »

I read an interview with the original inventor of the 555.

He was actually embarrassed at its crudeness, and would have done it very differently at the later date.

I guess there was an attempt at an updated version, but it didn't sell.

Re: Giant 555 Timer

#23

Post by dceddia »

mwattsun wrote: post #14

This is awesome. I built a metronome from a Forest Mims book and parts I bought at RadioShack back in the day, so it's nice to see the timer in all it's glory. One of my biggest surprises when I reported for duty on a submarine in the early 80's was that most of the electronic systems were discrete components. https://www.radioshack.com/products/getting-started-in-elect...

The other day, an HN post showed RadioShack.com has changed hands and the home page is all about a new type of crypto. Just checked, still is.

I’m surprised that RadioShack link still works, including the Add to Cart and Checkout buttons! Maybe the new owners are keeping the old e-commerce side alive?

Re: Giant 555 Timer

#24

Post by retrac »

mysterypie wrote: post #12

Since the original 555 was developed in 1971, I'm wondering if the inventor[1] or Signetics, the company where he worked, would have made a similar physical mock-up in those days before electronic circuit simulation software existed. [1] Apparently it was a single electronics engineer, https://en.wikipedia.org/wiki/Hans_Camenzind

Yes, almost certainly. Designs were routinely breadboarded into the 1980s. Maybe discrete transistors, maybe a mix of transistors and some simpler ICs. Even big designs got the treatment -- the Intel 4004 creators speak of a breadboard prototype in one of the oral histories.

My impression is that such prototypes were something given up quite reluctantly. It's the best way to verify your design works, after all. But eventually ICs developed enough. Either so tiny in process, that they behave electrically very different from circuits with macro components. Or simply so large in design, that it would cost more to build a discrete component prototype than just do a prototype mask run.

Re: Giant 555 Timer

#25

Post by scottlamb »

ncmncm wrote: post #22

I read an interview with the original inventor of the 555. He was actually embarrassed at its crudeness, and would have done it very differently at the later date. I guess there was an attempt at an updated version, but it didn't sell.

Found the interview: [1]

> The thing is that this is not a good design (the 555). I had a few years of experience, I’d say about five years, but I had no teacher, and I had to learn it by myself.

> You know it was really the beginning of design, so looking at it now, I would say “I wouldn’t do it like that again”. But nobody has actually changed it - it is still the same. They have shrunk it, they shrunk the dimensions. It was a 10 micrometer design, that was the standard size. You could make it in four (micrometers) now. This is more die per wafer, but nobody has changed the arrangement or the schematic.

> As a timer, you know, you trigger it and it runs for a certain time, it is very good. It has a temperature coefficient of like 23 parts per million. Over a large temperature range, that’s like .1 %. Its very stable. In free running mode, as an oscillator, its not so good, about 150 parts per million. And that you could improve down to about 10 ppm. So you could make an improved product. I’m amazed and stunned that in 30 years, somebody hasn’t looked at the schematic and said, “I can make this better”, so for the same area and same cost, and then they have a better product. Nobody has done that.

[1] http://www.semiconductormuseum.com/Transistors/LectureHall/C...

Re: Giant 555 Timer

#26

Post by hellbannedguy »

mwattsun wrote: post #14

This is awesome. I built a metronome from a Forest Mims book and parts I bought at RadioShack back in the day, so it's nice to see the timer in all it's glory. One of my biggest surprises when I reported for duty on a submarine in the early 80's was that most of the electronic systems were discrete components. https://www.radioshack.com/products/getting-started-in-elect...

No post body was provided.

Re: Giant 555 Timer

#28

Post by mwattsun »

dceddia wrote: post #23
mwattsun wrote: post #14

This is awesome. I built a metronome from a Forest Mims book and parts I bought at RadioShack back in the day, so it's nice to see the timer in all it's glory. One of my biggest surprises when I reported for duty on a submarine in the early 80's was that most of the electronic systems were discrete components. https://www.radioshack.com/products/getting-started-in-elect...

The other day, an HN post showed RadioShack.com has changed hands and the home page is all about a new type of crypto. Just checked, still is. I’m surprised that RadioShack link still works, including the Add to Cart and Checkout buttons! Maybe the new owners are keeping the old e-commerce side alive?

I was wondering that too. I did some road trips in 2020 and was surprised to run across a functioning RadioShack in Montpelier, Idaho [1] so it's not dead. There's even a Tandy Leather store in Portland [2]. According to Wikipedia, the eCommerce portal is a going concern along with 500 franchises [3] and the branding, which is now owned by Tai Lopez and Alex Mehr who are taking into crypto-currency. The Radio Shack saga continues. Probably not interesting to younger people, but I have to admire the staying power of the brand when companies come and go all the time. Especially when I consider the Fry's Electronics in Silicon Valley are all shut down or selling junk on consignment. I don't know what happened there.

[1] https://www.google.com/maps/search/radioshack/@42.3132621,-1...

[2] https://www.google.com/maps/place/Tandy+Leather+Portland+-+2...

[3] https://en.wikipedia.org/wiki/RadioShack

Re: Giant 555 Timer

#29

Post by CliffStoll »

logbiscuitswave wrote: post #21
2sk21 wrote: post #3

What a great project Idea! I have often looked at the internal schematic of the 555 and wondered if it could be made with discrete components - now I know that it is possible :-)

If you want something in kit form, I’m a big fan of this: https://shop.evilmadscientist.com/productsmenu/652 It’s a beautiful representation of a 555 timer in discrete component form - and functional too. The 555 timer itself is a pretty simple IC since it’s just a few dozen transistors and resistors at its core.

Evil Mad Scientist 555 timer kit is a beauty! Very sweet kit, and it looks wonderful.

Re: Giant 555 Timer

#30

Post by hulitu »

scottlamb wrote: post #25
ncmncm wrote: post #22

I read an interview with the original inventor of the 555. He was actually embarrassed at its crudeness, and would have done it very differently at the later date. I guess there was an attempt at an updated version, but it didn't sell.

Found the interview: [1] > The thing is that this is not a good design (the 555). I had a few years of experience, I’d say about five years, but I had no teacher, and I had to learn it by myself. > You know it was really the beginning of design, so looking at it now, I would say “I wouldn’t do it like that again”. But nobody has actually changed it - it is still the same. They have shrunk it, they shrunk the dimensio…

Of course he could make it better. Everybody can. The issue is if it makes sense. The only engineering science where improving something is (stil) cheap is SW. Although SW seems to be cursed and almost every improvement they make is a complete redesign. 555 is a cheap signal generator. It is very good at what he does. When you need a better one you can have a uC ( which you need to program and test) or a synthetiser ( which is more expensive). No need to thrash it just because it is old.
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