Re: Nannies want to stop you from building mains-powered projects

Tom Gardner wrote in news:IWAtE.162171 $ snipped-for-privacy@fx19.am:

My only shock event that was significant enough to have harmed me, was sitting indian style in front of my jacob's ladder. I accidently touched it. I am pretty sure it was isolated, but I ended up four feet back as my legs kicked out in front of me, and I am lucky to be here.

I can, however, take bare copper leads from the AC line and slowly creep up contact with them until my hands curl up. A couple inches of full grasp on each thumb and forefinger.

By the same token if I am working on a chassis and it is AC fed and live, and I accidentally touch the hot it almost gives me a heart attack.

The point being if one knows it is there and the voltage is low enough, some contact can be tolerated.

I worked in HV too however, and I also know that one only gets to make one mistake in that realm. Usually a live exit from such a mistake is a low likelyhood.

That is why HV engineering techs do NOT wear ESD straps. We caged the really high voltage stuff before we energized it anyway.

bitrex wrote in news:fZItE.174426$n55.171376 @fx02.iad:

Engineering level intelligence requires a good diagnostic prowess. Huge amounts of experience and education helps a lot. Top it off with a good conceptual view of things.

Still a shit practice. It would be far better to observe his students and assist those lacking to bring the entire class up to par together, with those whom excell assisting others as well.

I may not be smart enough to be an engineer but I'm smart enough to know that kind of BS smells like a setup, maybe teenagers and 20-somethings are naive enough to believe that no learned and honorable academic professional would ever do something like say, tip off his favorites to the situation in advance but I'm definitely not that naive at 40.

Professor is a job which like social worker, therapist, psychiatrist, priest, medical doctor, judge, politician, cop, etc. that is very attractive to both a lot of the right type of person and a lot of the wrong type of person

bitrex wrote in news:4rJtE.371642$ snipped-for-privacy@fx34.iad:

With this, I agree.

RESPECT MAH AUTHORITAH!

bitrex wrote in news:GJJtE.381510$Tr1.78565 @fx44.iad:

And then you went and made folks wonder which end of the spectrum you are hovering at.

Oh, and you left out lead guitarists!

Using optics to transfer power is of course handy, if you have significant common mode voltages.

One application for such system is bringing the current measurement down from a current transformer sitting on a 400 kVac EHT line.

Are there any other applications for such optically powered systems ?

And yet you give Phil Alison a shot at a job, even though he's never been to college and is scared to work on any equipment running at 3.3V or more. You're Mother Theresa and ICTFP.

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Grads since about 1980 have been pretty hopeless IME. Not just in technical subjects, but the whole gamut of courses. Probably^^^^^^^^definitely something to do with Socialism and the 'dumbing down' phenonmenon. They've all been tutored by someone like Bill Sloman who is determined to ensure no members of his classes graduate with a better understanding of the subject than he himself did 60 years ago.

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Ah. You're what today's young black yoof call "a playa". Respekt! ;-)

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i g

I remember being surprised when a labful of us (uni students) were tasked t o design & build a radio receiver, decode the data & use it to control a mo tor. Surprised because nearly everyone looked like a rabbit in headlights. Basic enough stuff.

Everyone had data error problems, but we were the only 2 to implement noise reduction. Why?

Some of us had done all that many years earlier and had moved on. Uni can't take away what people already know.

Of course there are slowmen out there. I encountered one prof like that but didn't let him stop me. But I suspect the biggest problem was the shortage of better students. If students were applying for an EE degree I'd really hope they'd actually done some electronics, and if possible quite a lot of it - too many just haven't. Whether that's down to the students or educator s earlier in the chain is another question.

NT

It's seriously advantageous to get *early* exposure to the fundamentals while the pupil is still very young. If a child of say 8,9 or ten has an elementary but solid understanding of what volts, amps and ohms, farads, henrys, frequency and periodicy really are and how they are related to each other then 10 years later they will have a *significant* head start over their peers at university who have not had that benefit.

I learned the Bohr-Rutherford atomic model, valency and elementary molecular VSEPR bonding at about that age, and even though B-R theory is

*heavily* flawed and grossly oversimplified, knowing the basic differences between atoms, electrons, protons, mixtures, compounds, molecules and complexes form the invaluable cornerstones of a skeleton on which to build a more complete understanding of these sciences much later in life. This is why the children of doctors and academics fair so much better than the rest when the time comes to get stuck into the serious study required to assure future success.

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Yes, learning stuff earlier is a big plus for later success. So do schools do that? Erm, nope.

NT

Welll, some do; I graduated public high school in 1969, and was taking my third year of calculus at the university in 1970. It was years later that I found colleagues less than comfortable with the subject, who'd come to it... late.

True, and it's only getting worse. The number of totally useless 'subjects' they're padding out the curriculum with expands every year. Certainly in the case of state schools anyway.

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'd

that's fairly late in the process, I was thinking of much younger. In some places soldering is taught to kids a few years old. Ideally children should be fed with all sorts of potential interests, both in school & at home. Fo r whatever reason they're mostly not - it might save a little now but what a great price the country pays for such shortsightedness.

It would in fact save people money. Today each parent buys so many educatio nal toys, and once used or rejected the money & opportunity is gone. Put th em in school where kids can play with them in lunch & breaks and each gets used time after time after time.

NT

All part of the long term infantilisation of society, as it makes them afraid to take risks and more dependent on the government and thus easier to control. Not forgetting the number of wastes of space people needed to enforce their rules. Sometimes wonder what happened to self reliance and taking responsibility for your life and your own actions. Bloody nanny statism sis a sign of a civilisation in decline, as all progress comes from those prepared to take risks.

The occasional shock was pretty par for the course in the tube electronics days, some serious, but taught one to be careful and have a healthy respect for high voltage circuitry in general. Despite all that, doubt if that many EE"s died from that cause. As for dimmers, built a first thyristor light dimmer in a switch plate around 1972. Shame i never thought of marketing it at the time...

Chris

You have told us that you are afraid of practically nothing. That strikes me as ill-informed. Sensible kids should be more nervous you seem to be.

Those who survived.

Possibly correctly. You may be less anxious than you ought to be.

They may have noticed that you weren't scared as often as you should have been.

Some people aren't very clever. Half the population has less than average intelligence ...

But the usual rule is that the council will only put up a warning sign after somebody has managed to kill themselves, which does limit the limit the number of warning signs they put up.

--
Bill Sloman, Sydney