John Curl's Blowtorch preamplifier part II

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I seem to spend a lot of time trying to explain physics to engineers, so they know why the thing they are trying to do does not work.

Interesting. I do the exact same thing here with physicists and superconducting magnets.

In the UK, and I suspect elsewhere too, the training of engineers contains far too little physics and maths. Instead, they are just taught to plug numbers into formulas and follow 'engineering rules'.
Actually, that is supposed to be the definition of engineering...the following of rules. But I agree with you that more physics and math is needed. I fear intuition however, cannot be taught.
As a result, much of the innovation in engineering is actually done by physicists.
And much of the high energy physics innovation is actually done by engineers. Well, ok, sometimes a chemist (Ray Davis).

It's actually a two way street...and it should be. Both groups bring a lot to the table. Here, the physicists bring really cool thinking to the table, and engineers have to figure out how to do it..
(OK, I admit it, I am biased; I am a physicist).
I won't hold that against you...:D

That's a shame. There was a time when British engineering was on par with or better than any in the world.
John

The British post office was responsible for a huge quantity of understandings when it comes to e/m, waveguides, radar... The state of scientific edu in general, seems lacking a bit..

I kinda feel the same way about analog and e/m theory in the USA..

Cheers, John
 
The British post office was responsible for a huge quantity of understandings when it comes to e/m, waveguides, radar... The state of scientific edu in general, seems lacking a bit..

Actually my education was mechanical engineering. My father warned me to stay away from EEs. :)

My field of interest at the time was internal combustion engines and of course other than Pratt and Whitney, the forefront of that field was at Rolls Royce and Bristol during the 30s and 40s when most of the great innovations occurred.

As for me, I never finished my degree, having decided on another course after my junior year, much to the consternation of my father and some of my professors. But I certainly enjoyed all of that basic background in math and physics.

John
 
My comments here are mostly hoping to give better understanding of 'misunderstandings' between many contributors here. When Ed Simon made his first response on the topic, I berated him for causing even MORE dissent here, with his strong personal opinions on who IS and who IS NOT a qualified engineer. I was arguing the other way, trying to unite everybody. Oh well.

John,

I don't think I have ever stated who or what I think an engineer is. I have stated the stupidest words you will hear some days are "I am an engineer and I know that XXXXX"

In some states you must pass the Professional Engineering exam to call yourself an engineer. Most places having a degree from an accredited college is sufficient. What many people do not know is how accreditation is done. It is not done by the government. Organizations such as the New England Association of Schools and Colleges, Middle States Commission on Higher Education, or a few others set the standards for their member institutions. There are actually non-accredited schools often called diploma mills, who often have much lower standards.

So where you go to school often counts for much.

ES
 
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Joined 2002
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John,

I don't think I have ever stated who or what I think an engineer is. I have stated the stupidest words you will hear some days are "I am an engineer and I know that XXXXX"

In some states you must pass the Professional Engineering exam to call yourself an engineer. Most places having a degree from an accredited college is sufficient. What many people do not know is how accreditation is done. It is not done by the government. Organizations such as the New England Association of Schools and Colleges, Middle States Commission on Higher Education, or a few others set the standards for their member institutions. There are actually non-accredited schools often called diploma mills, who often have much lower standards.

So where you go to school often counts for much.

ES

Actually I get lots of emails from people offering me any degree for a reasonable fee ;)

jan didden
 
I too have met physicists who barely knew which end of a soldering iron to hold. Sadly, some EEs too! I'm pleased to hear that other countries have not degraded their education as we have.

I once read somewhere that the engineering institutions in the UK did a review after WW2, because they realised that most of the innovations in EE (e.g. the magnetron) had been developed by physicists, not EEs. They decided to include much more science in engineering training. Unfortunately over the succeeding decades they seem to have slowly reverted to their old ways. We have a big problem with secondary schools too, as science and maths have been watered down there as well. I first studied calculus at age 15, now it is age 17 in most schools. When I started at university I already had three years calculus, now it would be one or possibly none. In addition, health and safety fears severely limit school lab experiments so students arrive at university with very poor practical skills.
 
Hi Jan,

Glad to see that vol.1 is out .Thanks.

............maybe vol,2 should have an article about dealing with the huge ego's found on this thread. :D They seem to forget that this is a diy site and some feel that that their level of education is of prime importance and humility seems to take second place. I have never seen so much rudeness and chest pounding in any other thread or forum.:(

Jam
 
I once read somewhere that the engineering institutions in the UK did a review after WW2, because they realised that most of the innovations in EE (e.g. the magnetron) had been developed by physicists, not EEs. They decided to include much more science in engineering training. Unfortunately over the succeeding decades they seem to have slowly reverted to their old ways.

The idea that innovations in Electronics (in the UK, 1930s-40s) were dominated by physicists stands up to very little scrutiny.

The example [Magnetron] is s DEVICE, very properly developed by physicists. But innovations in Engineering Electronics - Circuit-based applications - which at the time meant RADAR, Television, Stereophonic Sound, and Computers for example, were turned into reality by real Engineers - those who apply science, and are capable practitioners of the Art of Electronics (in the Horowitz & Hill definition).

In the UK at that time were at least two Engineers of that type, full worthy of respect, even at this distance:

Alan Blumlein, whose circuits and developments we still use on a daily basis [Long-tail pair, sterophonic sound, television circuits, early radar]

The Alan Blumlein Homepage

and Tommy Flowers, who turned Alan Turing's architectures into a 1943 valve computer:

Tommy Flowers - Wikipedia, the free encyclopedia

Flowers in particular was motivated to gain his education outside of the mainstream school-university standard-course sausage-machine. [Flowers took night classes in Electrical engineering during a mechanical apprenticeship]. I think that this is very characteristic of outstanding engineers - they will find the knowledge & skills from whatever unconventional source, and are quite independent of the general level of available instruction.

Naturally, good instruction is very necessary to generate "ordinary" engineers - plodders to develop and draw ordinary objects for uncritical mass-market business. BUT these are not actually required in the UK today - there's very little for them to do! Those that need their Engineering presented to them in term [semester] -sized doses may as well go and be a bank clerk.

Real Engineers will emerge, regardless of educational standards. It is enough for a young engineer to find something worth taking to pieces, for the journey to begin.
 
As I said, I was reporting what I read somewhere. I have not done independent historical research to verify it. I do not deny that there was, and still are, some very good engineers. Blumlein and Flowers are obvious examples.

On the other hand, there is the head of the UK General Post Office (an engineer) who knew he had a problem with long telephone lines but refused to accept the solution (add inductance) offered by Oliver Heaviside because it was so counter-intuitive. He was not impressed by Heaviside's maths, so assumed he must be wrong. Heaviside took his solution to America, where people listened to him and tried it. It worked (of course, as the maths was correct) so the US had decent long distance telephone lines before the UK, even though the solution was found over here.
 
On the other hand, there is the head of the UK General Post Office (an engineer) who knew he had a problem with long telephone lines but refused to accept the solution (add inductance) offered by Oliver Heaviside because it was so counter-intuitive. He was not impressed by Heaviside's maths, so assumed he must be wrong. Heaviside took his solution to America, where people listened to him and tried it. It worked (of course, as the maths was correct) so the US had decent long distance telephone lines before the UK, even though the solution was found over here.

I am not sure of the nature of your claim from this assertion. That Engineers are ignorant of mathematics, and therefore responsible for the demise of the UK's infrastructure?

If that is so, the only thing we can learn is that you have never known so much as a half-capable design engineer. I suppose that is likely enough, given the large proportion of poor examples around.

But if you meet any Real Engineers, you will find that we take mathematics seriously. Look at Blumlein's biography if you need a historical example - he prioritised mathematics above learning to read, even.

Today, many quasi-engineers hide behind SPICE and calculators and spreadsheets to attempt to tackle design problems, with uniformly poor outcomes. Their phoney nature is easy for a real engineer to spot, less easy for others.

Another consideration: before these simulating & calculating-crutches emerged, Laplace transforms were required to deal with even simple Electrical Engineering questions. I do not practice these on a daily basis, but even so, I would not call myself a professional without being quite sure about how these problems are tackled using Laplace, and what the formulations actually signify. Similarly with Fourier Transforms. Sure your PC can do all manner of things through FFTs, but do you know what the transform is actually doing? A Real Engineer must be able to say Yes.
 
As I said, I was reporting what I read somewhere. I have not done independent historical research to verify it. I do not deny that there was, and still are, some very good engineers. Blumlein and Flowers are obvious examples.

On the other hand, there is the head of the UK General Post Office (an engineer) who knew he had a problem with long telephone lines but refused to accept the solution (add inductance) offered by Oliver Heaviside because it was so counter-intuitive. He was not impressed by Heaviside's maths, so assumed he must be wrong. Heaviside took his solution to America, where people listened to him and tried it. It worked (of course, as the maths was correct) so the US had decent long distance telephone lines before the UK, even though the solution was found over here.

I know of many examples of EEs that do not listen to suggestions from others, especially when they are non-intuitive, but one can always find such examples. Math and physicists are guilty of the same problem. But those were undoubtedly EEs at Bell Labs who presumably listened to Heavyside (assuming that this story is true, and that BTL guys did not come to the same conclusion first). There are plenty of EEs that listen, understand how to treat non-intuitive things, and turn them into reality.

Cheers,
Bob
 
Back in Heaviside's day, engineers (at least in the UK) were not taught as much maths as they are today. They prided themselves as being 'practical men'. Now of course there is a place for practical men - someone has to get things done. The problem is that unless they could intuitively understand something they tended to assume it must be wrong. A similar issue cropped up with modulation sidebands - many radio engineers considered sidebands to be a mathematical fiction until someone demonstrated their physical existence.

The situation is better today, but not much better. In my opinion it probably improved significantly in the 1960's and 70's, but has since declined (in the UK). Yes, engineers ought to understand Fourier and Laplace transforms and some do, but many do not. Yes, I do believe that part of the UK's relative decline in technology is due to a decline in training standards for engineers (and scientists - standards have dropped there too).

I have met and worked with some excellent engineers, so please don't think I am criticising all of them. In fact I am not criticising engineers at all, but their teachers. We have a double problem in the UK: not enough science and maths, but also not enough practical 'hands on' engineering in the courses either. Both Fourier and soldering are beyond them.
 
But those were undoubtedly EEs at Bell Labs who presumably listened to Heavyside
That would have been Harold Arnold and Gustav Elmen of Bell Labs (Western Electric Research Laboratories at the time). Arnold was the first director of BTL and Elmen led the development of Permalloy for loading trans-Atlantic cables. Arnold was a physicist and Elmen was an EE.

John
 
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Not sure about that, PE has specific legal meanings like being able to sign off on drawings, etc.

Texas for one requires a PE to call yourself an engineer, as opposed to doing engineering.

A PE is required just about everywhere in the US if you do designs that concern "Life-Safety." Although that is usually structural, civil engineers (It is clear there are only un-civil engineers here) and electrical engineers doing building power designs. It can also include designers of medical equipment or even voice evacuation and notification systems.

The common use is for junior or non-PE staff to do the designs under the supervision of a PE who then is supposed to review and stamp the final drawings.

On a recent project I had to use a new structural engineer to review and approve (stamp) my attachment method drawings. My usual firm did not have enough insurance for the project size. (They would have had to pay about $100,000 more total over 10 years)

The new folks took two weeks to review my first set of drawings. They checked each and every calculation. The second set only took two days. They mentioned that on the first set everything had been over designed by a factor of 5 or more, (Safety factor is the ratio of expected load to failure point) so they felt comfortable just checking the major issues after that. A safety factor of 5 is pretty standard for stuff hung over peoples' heads except in California. There you not only allow for stuff not falling, but also that if launched into the air by an earthquake it is going up either.

Seems as bad as Japan's earthquake was their buildings stood up well, so kudos to those who do it well.
 
That would have been Harold Arnold and Gustav Elmen of Bell Labs. Arnold was the first director of BTL and Elmen led the development of Permalloy for loading trans-Atlantic cables. They were both physicists.
John

Yes at first there were physicists, because you did not get radio engineers until after the vacuum tube was invented! The first engineers were what we now call civil engineers, starting around 1850!

Physicists of course date back to prebiblical times. I refer to the first line of Genesis for proof. It is a very exact description of the world of physics.
 
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Yes, I do believe that part of the UK's relative decline in technology is due to a decline in training standards for engineers

My belief is that is it a direct result of the public's lack of desire in the sciences. As such, it is engineers, physicists, scientists..all of em.

It was noted here in the US, that for the general public to understand a scientific article, the article had to be written at a 12 year old's level.

Try as I may via the tours I give, I've not been able to dispute that assertion.

It makes me unhappy.

Cheers, John
 
GRRR! WOW! UNEXPECTED!

I just did another check on my transformer that is connected to an AC line with a DC offset of .88 volts measured by the circuit shown earlier. I used one meter on the input and another on the output. Same meters for all of the measurements.

As you can see there was some jiggle in the AC Mains so looking at the in to out ratio shows A STEADY LOSS OF OUTPUT! I would have expected an offset in the hysteresis loop but not a shift! This is a small signal transformer rated for 48 VCT out at 125ma. It is loaded by a pair of 1K resistors to the center tap. So it is a bit hotter due to the lack of load.


Input Out Ratio Ratio Diff % Out Drop
125.2 60 0.479233227 0 0
125.5 60 0.478087649 0.001145577 0.239043825
126.6 60.5 0.477883096 0.00135013 0.281727225
125.6 60 0.477707006 0.00152622 0.318471338
123.9 59.1 0.476997579 0.002235648 0.466505246
125.2 59.6 0.476038339 0.003194888 0.666666667


Again not the expected result! The transformer is actually becoming less efficient!


J.N. Do I need to explain this more clearly for the crowd here? :)


Note the table does not save column spacing when it goes from preparing to posting! Sorry!
 
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