A recent post has reminded me of a misconception one of my younger club members had regarding current. His tutor at school had been teaching Ohms law, but in a way that had caused confusion.
From what he had been taught, he assumed that you could not "feed" a specific current to a load, only that the load would draw whatever current it required. Whilst this is true when fed from a fixed voltage source, he was brain frozen by the way he had been taught and unable to grasp that if you need a fixed current, simply use Ohms law to determine the voltage required to cause that current through the load.
He then asked me "what if I don't know the resistance" again I tried to refer him to Ohms law, but it was only by a practical demonstration, that he instantly grasped the concept. All I did was connect a resistor to a variable power supply which indicated both voltage and current, and increased the voltage whilst noting the changing current as I did so.
My point is, what has changed in teaching that left him so confused? he is not stupid by any means, and I'm sure it has something to do with the way basic electronics is being taught nowadays. I read through a reference he had been given on the subject that seemed overly complicated and had so many paragraphs that it was "word blind" to read. Apparently the teacher is a whizz at programming, and in his haste to get the students all proficient in that aspect of electronics, he is neglecting some of the fundamentals that are in my opinion, still essential to fully understand.
Oh dear, I'm just glad we straightened that out for him.

 

Just my opinion here, but I think that really smart people make poor teachers. Because what seems so easy to them - they overlook and neglect to build a solid foundation. The beginner may not understand the relationships between changing voltages and currents the way the teacher does, and the teacher explains exactly how it works on a "Nuclear Physicists" level of understanding.

I just got my CQI certificate (Certified Quality Inspector). The book I studied from was - um - to say the least - written by a genius. That leaves me in the dust. While talking about P being equal to (for instance) -1 > Z > -2, I struggled to gain the concept behind it. OK, you see it clearly, but that's because the way I put it. While trying to figure all this stuff out and following the page closely, all of a sudden 2K appeared without ANY explanation to where it comes from or why. I spent two weeks studying three pages. I finally got a hold of another book that took the time to explain the simple things in life. Well, in statistics and charting. And after all that work, the genius who wrote the first book never even bothered to put any questions in that had anything to do with P charting.

Some people are not suited for teaching. Just ask some of the younger inspectors I've trained. It gets real easy to overlook the simple things, assuming "any idiot should know that." Well, it's not the students fault if the teacher is incapable of disseminating information in a manor suited to the student and their level of understanding.

 

Some people are not suited for teaching. Just ask some of the younger inspectors I've trained. It gets real easy to overlook the simple things, assuming "any idiot should know that." Well, it's not the students fault if the teacher is incapable of discriminating information in a manor suited to the student and their level of understanding.

AKA 'Dumbing Down'!
Max.

 

discriminating; disseminating - I hate spell check!

 

Just my opinion here, but I think that really smart people make poor teachers. Because what seems so easy to them - they overlook and neglect to build a solid foundation. The beginner may not understand the relationships between changing voltages and currents the way the teacher does, and the teacher explains exactly how it works on a "Nuclear Physicists" level of understanding.

I just got my CQI certificate (Certified Quality Inspector). The book I studied from was - um - to say the least - written by a genius. That leaves me in the dust. While talking about P being equal to (for instance) -1 > Z > -2, I struggled to gain the concept behind it. OK, you see it clearly, but that's because the way I put it. While trying to figure all this stuff out and following the page closely, all of a sudden 2K appeared without ANY explanation to where it comes from or why. I spent two weeks studying three pages. I finally got a hold of another book that took the time to explain the simple things in life. Well, in statistics and charting. And after all that work, the genius who wrote the first book never even bothered to put any questions in that had anything to do with P charting.

Some people are not suited for teaching. Just ask some of the younger inspectors I've trained. It gets real easy to overlook the simple things, assuming "any idiot should know that." Well, it's not the students fault if the teacher is incapable of disseminating information in a manor suited to the student and their level of understanding.

Yes I agree, it is rather like the written instructions for a piece of equipment, the LAST people who should write it are the ones who designed it because they know it inside out and unknowingly, may take for granted that something is self evident. To the un-initiated, it may be far from clear. Better to have people outside of the design team work with the designers and find all the "non understandable" parts, then get a selection of people from the intended market to try. Revise instructions as necessary until the village idiot can do it in his sleep.

I once had a cheap Chinese torch with a label on it that read..... "When light become dim, insert 2 new batteries into your rear"... Well when I tried that, all that lit up where my eyes!!

 

I look at his problem and say "Yes, you are absolutely right. If you know only the current you want but don't know the resistance you have no way to predict (calculate) the voltage required." If you aren't able to make a measurement to determine on more of the three variables in Ohm's law, you are indeed stuck.

 

A recent post has reminded me of a misconception one of my younger club members had regarding current. His tutor at school had been teaching Ohms law, but in a way that had caused confusion.
From what he had been taught, he assumed that you could not "feed" a specific current to a load, only that the load would draw whatever current it required. Whilst this is true when fed from a fixed voltage source, he was brain frozen by the way he had been taught and unable to grasp that if you need a fixed current, simply use Ohms law to determine the voltage required to cause that current through the load.
He then asked me "what if I don't know the resistance" again I tried to refer him to Ohms law, but it was only by a practical demonstration, that he instantly grasped the concept. All I did was connect a resistor to a variable power supply which indicated both voltage and current, and increased the voltage whilst noting the changing current as I did so.
My point is, what has changed in teaching that left him so confused? he is not stupid by any means, and I'm sure it has something to do with the way basic electronics is being taught nowadays. I read through a reference he had been given on the subject that seemed overly complicated and had so many paragraphs that it was "word blind" to read. Apparently the teacher is a whizz at programming, and in his haste to get the students all proficient in that aspect of electronics, he is neglecting some of the fundamentals that are in my opinion, still essential to fully understand.
Oh dear, I'm just glad we straightened that out for him.

Here is mine: confused does not mean stupid, a lot will use that to make you stupid though. They do not study the basics of electronics like MicroElectronics and Semiconductors. There is no voltage and power in real life, those are virtual parameters that we use to calculate, there are only a directed movement of electrons, or electrical charges if you prefer. As for the explanation, it comes from voltage and current generators. A voltage generator has fixed voltage, a current generator has fixed current. This is important!

 

Then a "constant resistance" or "constant power" power supply or variable will really throw him off.

How about a 4 quadrant power supply which is typically called a "Voltage source",

Look at Kepco BOP series.

and

http://www.testequipmentdepot.com/bk-precision/electronic-load/stand-alone/index.htm

and these (SMU) wierd things: https://www.tek.com/keithley-source-measure-units

 

Just my opinion here, but I think that really smart people make poor teachers. Because what seems so easy to them - they overlook and neglect to build a solid foundation. The beginner may not understand the relationships between changing voltages and currents the way the teacher does, and the teacher explains exactly how it works on a "Nuclear Physicists" level of understanding.

That's a blast from the past! The professor on my Nuclear Physics course was a Nobel Prize winner, but not particularly good at explaining things.

 

Why is that I feel that a teacher was judged by what a confused student says/does

Dare to say, not fair.

 

A recent post has reminded me of a misconception one of my younger club members had regarding current. His tutor at school had been teaching Ohms law, but in a way that had caused confusion.
From what he had been taught, he assumed that you could not "feed" a specific current to a load, only that the load would draw whatever current it required. Whilst this is true when fed from a fixed voltage source, he was brain frozen by the way he had been taught and unable to grasp that if you need a fixed current, simply use Ohms law to determine the voltage required to cause that current through the load.
He then asked me "what if I don't know the resistance" again I tried to refer him to Ohms law, but it was only by a practical demonstration, that he instantly grasped the concept. All I did was connect a resistor to a variable power supply which indicated both voltage and current, and increased the voltage whilst noting the changing current as I did so.
My point is, what has changed in teaching that left him so confused? he is not stupid by any means, and I'm sure it has something to do with the way basic electronics is being taught nowadays. I read through a reference he had been given on the subject that seemed overly complicated and had so many paragraphs that it was "word blind" to read. Apparently the teacher is a whizz at programming, and in his haste to get the students all proficient in that aspect of electronics, he is neglecting some of the fundamentals that are in my opinion, still essential to fully understand.
Oh dear, I'm just glad we straightened that out for him.

While I could (and have) go on at length about the changes in the quality of education, it's impossible to say anything meaningful from the experience with a single student. We each get blinders on when we learn some concept from one perspective and then start thinking that that is the only way to view the problem. It can be hard to take those blinders off until we are forced to because we naturally insist on looking at the problem with those blinders in place.

I might have answered he question about what if we didn't know the resistance by asking what would happen if we put the unknown resistance in series with a known resistance and then applied a voltage to the series combination and adjusted it until we got the desired voltage across the known resistor that corresponds to the current we want flowing in both.

 

Why is that I feel that a teacher was judged by a what confused student says/does

Dare to say, not fair.

I agree. And again, I'm not convinced the person was what I would call confused. It looks to me more like he recognized that he had an equation in three variables, knew the value of only one and was therefore stymied. Progress then depends on how much the student knows about laboratory methods that could be used to determine one more of the unknowns.

On the topic of manuals:
To anyone who thinks writing instructions to do something is easy, try writing instructions for folding a piece of paper "in half" without using illustrations.

 

Why is that I feel that a teacher was judged by a what confused student says/does

Dare to say, not fair.

Maybe if the teacher had taken more time to check that his pupils had understood his teachings, then maybe the student would not have been confused.
Seems to me, that all to often I hear that many things are rushed so as to get everyone onto the next subject. Those that don't quite get it the first time, are left to sink or swim by their own devices.
I can remember that when I was in junior school, I had a severe dose of food poisoning and missed out some important maths lessons. On my return, the science/maths master took me out of P.E (which he knew I hated) and, on a one to one basis, ensured that I caught up. That was in the days when we had 48 pupils per class in the mid 1950's. Now they have half that number per class, but are so bogged down by all the red tape that they do not have the time to do that sort of thing, or, maybe some are not bothered anyway.

 

Which half? A square piece of paper makes it easy.

Try:
Imagine an imaginary line parallel to the long edge, 1/2 the distance of the short edge.
Fold the paper along that imaginary line.

What is so hard about that?

 

While I could (and have) go on at length about the changes in the quality of education, it's impossible to say anything meaningful from the experience with a single student. We each get blinders on when we learn some concept from one perspective and then start thinking that that is the only way to view the problem. It can be hard to take those blinders off until we are forced to because we naturally insist on looking at the problem with those blinders in place.

I might have answered he question about what if we didn't know the resistance by asking what would happen if we put the unknown resistance in series with a known resistance and then applied a voltage to the series combination and adjusted it until we got the desired voltage across the known resistor that corresponds to the current we want flowing in both.

Oh yes, in fact even though I tried to explain as you outlined above, it was only the practical demonstration that unlocked the blinders that had so obscured his view.
I wonder how many instances of things in life could be so different with a little more understanding. What was it the guy who was involved with staring at goats said? He took the blinders off the soldiers he trained. ( those that don't know, the U.S military and others were experimenting with mind control and tried to stop the heart of goats by mental thought along with other things like remote viewing etc.)

 

I try to be a "ghost" in my classes, then I don't have to go and get an "A". I managed it twice. On one occasion, teach said, "If I had better things to do, don't bother coming to class". Works for me. I got an incomplete at a bad time so I graduated the next Semester. He forgot.

I graduated from another school on a transfer of credits. I also graduated from that school while on a "leave of abcesnse".

 

Which half? A square piece of paper makes it easy.

Try:
Imagine an imaginary line parallel to the long edge, 1/2 the distance of the short edge.
Fold the paper along that imaginary line.

What is so hard about that?

For openers, it assumes the concept of "parallel."

 

I agree. And again, I'm not convinced the person was what I would call confused. It looks to me more like he recognized that he had an equation in three variables, knew the value of only one and was therefore stymied. Progress then depends on how much the student knows about laboratory methods that could be used to determine one more of the unknowns.

On the topic of manuals:
To anyone who thinks writing instructions to do something is easy, try writing instructions for folding a piece of paper "in half" without using illustrations.

A picture is worth a thousand words

 

For openers, it assumes the concept of "parallel."

Give me a beak. Maybe, you need to describe your audience.

 

While I could (and have) go on at length about the changes in the quality of education, it's impossible to say anything meaningful from the experience with a single student. We each get blinders on when we learn some concept from one perspective and then start thinking that that is the only way to view the problem. It can be hard to take those blinders off until we are forced to because we naturally insist on looking at the problem with those blinders in place.

I might have answered he question about what if we didn't know the resistance by asking what would happen if we put the unknown resistance in series with a known resistance and then applied a voltage to the series combination and adjusted it until we got the desired voltage across the known resistor that corresponds to the current we want flowing in both.

I was thinking of that too.