Well, it still seems to be a saleable skill, but only to people to who share your ignorance of more modern alternative. It's roughly on a par with being able to cast horoscopes.
Probably. You should be able to grind flint a lot faster and more accurately than you can knap it.
What I had in mind were modern tools that can do the job that hand- axes were made to handle. Nobody seems to know quite what that was, so it's kind of difficult to identify which of the gadgets you can buy at a hardware as the hand-axe replacement. The phrase "the job" is admittedly ambiguous, but since we don't know what that was it's difficult to construct a sentence that excludes that particular ambiguity.
The paper was finally published in 1978, but I designed the circuit and laid out the printed circuit board after hours, as a hobby project a few years earlier, when I was working on the project for which the
555 was a hopelessly inadequate candidate component.It uses MC10102's, and MC10231 and an MC10131 - 10K rather than 100K, but it also uses four Am 685 comparators, which a a bit more prone to complain if you don't give them a well-grounded environment. It was my first ECL board of any sort, realised as a double-sided board with lots of ground plane on both side, tied together with quite a few through the board pins and it worked without modification.
It stopped working a few months later, when one of the through pins proved to have been imperfectly soldered to one side of the ground plane, but that didn't take long to find and fix (if you discount the two hour drive from to Luton to Southampton).
It a a fun project, and probably helped me get my next job - at EMI Central Research - where I was working by the time the paper finally got published.
So we both got into ECL fairly early. I seem to have done rather more with it.
There are lots of applications for the 555 - if very few these days where it is the best choice.
Finding a single application where it is or isn't the best choice doesn't really say much about my point, because it's going to be cherry-picked one way or the other.
group
The evidence suggests that you mostly don't spend any time looking any further.
That must be on sci.electronics.basics.
Here I seem to remember a request for a micro-power 100kHz oscillator, where your answer involved a 100mH inductor.
When I looked around for 100mH inductors that the OP could buy, the only one available seemed to have too low a self-resonant frequency to work at 100kHz. The next inductor down the range had an appreciably higher self-resonant frequency, and I posted an LTSpice simulation that suggested that it could work.
Of course, it drew more power than my preferred solution which - IIRR
- depended two BFR92 wide-band transistors, which happen to have a very low collector emitter capacitance, which is what eats up the power in that kind of circuit.
My solution was also cheaper, more compact and a lot easier to understand, since it was just an elementary based-coupled two transistor multivibrator - the only complication was the voltage division to protect the base-emitter junctions from the collector voltage swing. Wideband transistors have very shallow base diffusions, and Vebo for the BFR92 is only 2V.
But keep on congratulating yourself on your techical skills, Nobody else is going to do it for you.
The wheel might not be big and bulky, but the housing that would accomodate eight detector diodes and let them see only their own own spot on the code wheel is going to be a little more demanding.
If it had been directed at you, who doesn't really understand practical - as in 100mH inductors with a self-resonant frequency above
100kHz - it would have been wasted effort, but it also served to warn the lurkers that you have an exaggerated idea of you own competence.You aren't as over-confident as John Larkin, but you've got rather less to be over-confident about.
-- Bill Sloman, Nijmegen