Who is your favourite electronics guru?

In message , dated Sat, 12 Aug 2006, John Fields writes

Depends what you have in your hand.

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OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
2006 is YMMVI- Your mileage may vary immensely.

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

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What did you have in mind?

In message , dated Sat, 12 Aug 2006, John Fields writes

A large stockpile of weapons.

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OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
2006 is YMMVI- Your mileage may vary immensely.

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

How would you know?

Just the thing for the dumb newby.

Not exactly. The absence of any modern competitior for the 555's slot has more to say about the absence of any serious application for the

555 in mass-produced devices than it has to say about the quality of the original design.

Now go back to knapping a couple more fruit knives for your dinner tonight.

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Bill Sloman, Nijmegen

Interesting thought. I use 555s a lot developing one-of-a-kind prototypes. But I'm inclined to agree that in a more complex, more systematically designed system, there probably aren't going to be many 555-shaped holes, so to speak. Switching and timing are done by the CPU if there is one. Oscillators can be cobbled together out of leftover gates. And so on.

In one of my current projects I am deliberating between a 555 and an 8-pin microcontroller. Given that we save a couple of diodes and capacitors, the micro may be cheaper! And it opens up the possibility of adding other intelligent behavior, response to additional sensors, soft start-up, status indicators, etc., all by just writing more code.

The appeal of the 555 is that I can give a hobbyist a circuit that can be built with Radio Shack parts, with no device programming.

Each to their own, for me Robert Noyce and Jack S. Kilby.

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 JosephKK
 Gegen dummheit kampfen die Gotter Selbst, vergebens.  
  --Schiller

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Many thanks,

Don Lancaster                          voice phone: (928)428-4073
Synergetics   3860 West First Street   Box 809 Thatcher, AZ 85552
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I work for a living.

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Precisely.

Most requests on these groups don\'t ask for, "How can I program a
microcontroller to do this or that?" , they ask for a circuit which
can do what they want to be done and  which can be built with  glue
logic and  discretes.

Anything done of will is spiritual as well, even the analysis.

--
 JosephKK
 Gegen dummheit kampfen die Gotter Selbst, vergebens.  
  --Schiller

I think i will make that my cut point for a Real (tm) engineer. Well EE.

--
 JosephKK
 Gegen dummheit kampfen die Gotter Selbst, vergebens.  
  --Schiller

In message , dated Sun,

13 Aug 2006, joseph2k writes

But Kevin A will point out that 'will' is an illusion, anyway. So where does that leave 'spirituality'? Can it even be defined?

--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
2006 is YMMVI- Your mileage may vary immensely.

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

And you come up with a 555-based solution - to the man with a hammer, everything looks like a nail.

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Bill Sloman, Nijmegen

Well, that is the way you see it. Hans Camenzind's "Designing Analog Chips" makes it pretty clear that the only stroke of genius in the 555 was the insight that let him squeeze the function into an 8-pin package

- he points out a couple of faults in the original design and outlines how he'd redesign it today (2004) if he had the chance.

I don't hate it - I despise it, which isn't quite the same thing. And my experience has been that for any task for which the 555 has been "eminently suited" there has been a better way of tackling the problem

- usually based on looking at the system as whole.

I have worked in environments where precise and stable time delays tend to be required, which does put the 555 at a disadvantage, even without your "magic diode" to further degrade the temperature stability and the power supply rejection ratio.

So why don't you learn about more modern ways of turning on a relay after a time delay? The 555 (like the 741) is a hold-over from the Stone Age of modern electronics.

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Bill Sloman, Nijmegen

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When two boards need to be nailed together, a hammer and a nail will
do the job admirably.

Of course, since your hatred of hammers and nails is so
overwhelming, your propensity would be to suggest gluing them
together, screwing them together, or any number of other less
practical methods.  If a hammer and a nail would do the job
satisfactorily, though, and there were no requirements other than
that, why not go that way?

Because you\'re a spoiled brat and you don\'t have the common decency
to admit when you\'re wrong, that\'s why.

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It was partly that, but it was mostly the ratiometric voltage
divider and the two comparators which made the circuit insensitive
to supply and temperature variations.

You've got to be pretty unsophisticated to see that as a stroke of genius. If the voltage divider had been made with stable resistors, the part might have usual for professional electronics.

Yes, he does show the circuits, but he doesn't show the aspect ratios of the reistors and all the other fine detail that makes a complete design.

Because the dumb newbies who put up the applications have over-simplified their system requirements to the point where the 555 looks like a solution - almost alwasy to the wrong problem.

Nitwit. I've never used a CD4047 in a real design, and it certainly isn't one of my favourite parts. You are setting up a straw man with even less than your usual subtlety.

I don't have to work at not using the 555 - it simply isn't a part that professional engineers use very often. I've never had a design review where anybody - even the idiot manager - has asked me why I didn't use a 555.

Not usually necessary.

I'm on the dole because I'm too old - the only chances of work that I've seen have arisen from my demonstrable competence, so you've got my situation exactly 180 degrees wrong.

Yes, it was a silly question to ask you. Rather like asking a stream train enthusiast what he thinks of the Japanese bullet train or the French TGV, or the German ICE.

As it happens, I have survived since then, but - unlike you - I did keep an eye on the new components as they became available and adapted my design style to accommodate them - which is more than you seem to have managed.

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Bill Sloman, Nijmegen

And if a nail works, why not? The 555 is a very handy gadget for implementing small, simple control circuits.

Having said that... 555s in commercial products appear to be rare. Offhand I can only think of one instance. The original IBM PC gameport used a 558 (quad 555) to sense the joystick potentiometers by determining how long it took to charge a capacitor.

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Yeah, once you\'ve been shown the trick it\'s easy to say there\'s not
much to it...

And, BTW, it _is_ stable. The resistors are isothermal and pretty
close to the same value, so the TRIGGER and THRESHOLD voltages are
always 1/3Vcc and 2/3Vcc, regardless of supply or temperature
variations.  There are limits, of course, just read the spec\'s.