when will they ever learn?

[Murflynn]

 

 

A first class example of someone trying to learn and being confused by posters here who persist in stating current in "Amps per hour", and claiming 'everyone knows what is meant' when corrected.

 

Dear OP, there are two or three posters on here who do this deliberately, thinking it's funny. Watch out for them, you'll figure out who pretty quickly.

s'allright, Mike, I've got the pillocks well sussed out, thanks.

[dmr]

Thanks all for the answers, and for furthering my education - at least I'm getting an idea of how much I don't know!

 

A supplementary question related to current flow and electron flow, and the fact they flow in different directions. Wiring diagrams - should these be read positive to negative (direction of current flow) or negative to positive (direction of electron flow)? Thinking about it further, I guess the more relevant question is "is a wiring diagram only meant to show which components are in a particular circuit" because if so, knowing which direction stuff flows in is irrelevant?

 

Forget about electrons, conventional current is what we deal in and this goes positive to negative.

Out of interest, the naming of positive and negative and the concept of a flowing current was all arbitrarily decided a long time before electrons were discovered. It was a 50:50 guess and maybe they got it wrong.

 

A wiring diagram shows how things are connected together rather than the direction of current flow. However it is good practice to have the positive wires at the top of the drawing and the negative ones at the bottom and to draw it in such a way they current flows generally downwards and left to right, though more strictly it actually flows in a continuous loop so is really flowing clockwise.

 

A lot of people, professionals included, draw circuit/wiring diagrams very badly.

 

...............Dave

[nb Innisfree]

Conflicting advice is counterproductive, I would advise any newcomer to the electric game to learn from books, the printed word is much more considered and therefore more reliable.

 

Once you have gained the basic knowledge then you know what specific questions to ask.

[Tacet]

It grates for me to see it, it should be "High Current", but I feel like the sole voice shouting in the wind.

 

Tony

 

Does anyone have issues with "throttle" being used in connection with a (conventional) diesel engine? Its frequent use doesn't cause any real confusion - but to my way of thinking, it is not strictly correct.

[nicknorman]

Does anyone have issues with "throttle" being used in connection with a (conventional) diesel engine? Its frequent use doesn't cause any real confusion - but to my way of thinking, it is not strictly correct.

Oh no, you are going to let on that all those old crusties with ancient boats with "speed wheels" have it right and people living in the 21st century with "throttles" are wrong. I was really hoping no-one would notice.

[cuthound]

Forget about electrons, conventional current is what we deal in and this goes positive to negative.

Out of interest, the naming of positive and negative and the concept of a flowing current was all arbitrarily decided a long time before electrons were discovered. It was a 50:50 guess and maybe they got it wrong.

 

A wiring diagram shows how things are connected together rather than the direction of current flow. However it is good practice to have the positive wires at the top of the drawing and the negative ones at the bottom and to draw it in such a way they current flows generally downwards and left to right, though more strictly it actually flows in a continuous loop so is really flowing clockwise.

 

A lot of people, professionals included, draw circuit/wiring diagrams very badly.

 

...............Dave

I was always told to draw circuit diagrams from bottom to top, as most building have their power input on the basement and it rises up the building. Always seemed logical to me.

 

However I don't think there is a correct convention.

 

Edited for spillung.

Edited February 19, 2016 by cuthound

[John V]

 

A wiring diagram shows how things are connected together rather than the direction of current flow. However it is good practice to have the positive wires at the top of the drawing and the negative ones at the bottom

 

Warning pedant alert !!! People trying to learn please ignore !!!

 

Of course with early transistor circuits they were usually drawn with th positive rail at the top, following the convention of valve drawings.

As NPN started to replace PNP there was a tendency to draw the circuits in the same (easily recognisable) format just reversing the voltage (and of course the electrolytic capacitors and diodes) putting the negative rail at the top

[WotEver]

 

Warning pedant alert !!! People trying to learn please ignore !!!

 

Of course with early transistor circuits they were usually drawn with th positive rail at the top, following the convention of valve drawings.

As NPN started to replace PNP there was a tendency to draw the circuits in the same (easily recognisable) format just reversing the voltage (and of course the electrolytic capacitors and diodes) putting the negative rail at the top

I'm not sure that's true at all. I can't think of any circuit that I've seen that shows a -ve rail at the top.

 

Not only that but NPN have never 'replaced' PNP - both are frequently used in circuits up to this day.

 

Silicon replaced germanium back in the early 70s (thank God!) but that has nothing to do with polarity.

 

Tony

[RLWP]

 

Does anyone have issues with "throttle" being used in connection with a (conventional) diesel engine? Its frequent use doesn't cause any real confusion - but to my way of thinking, it is not strictly correct.

 

I generally try to use 'speed control', although I occasionally forget

 

Richard

[John V]

when OC71 / 2s were about the best you could buy (I still have an OC72 I purchased that cost 17/6 and came with 2" leads packed in an individual cardboard box) I used to lust after silicon NPN transistors but couldn't afford them for a long time. I can assure you that Wireless World / Practical Wireless

were full of circuits drawn in this fashion. I certainly had a couple of textbooks on electronics using this method.

[dmr]

 

Does anyone have issues with "throttle" being used in connection with a (conventional) diesel engine? Its frequent use doesn't cause any real confusion - but to my way of thinking, it is not strictly correct.

 

I believe rack is (or was) the correct term so one would talk of "full rack" rather than "full throttle", but I guess its pointless using words if nobody else understands them. I'm moored in Devizes for a week or two and just up from me is a "winding hole" with a CaRT sign calling it a "Turning Place for Boats".

 

I guess we now have a whole generation of drivers who have no concept of what a throttle actually does, let alone a choke.

 

...............Dave

[ditchcrawler]

the sequel is resistance which is universally used, whereas ohmage would not be recognised by anyone.

however, on the other hand, potential (difference) is rarely used and voltage is the norm.

 

English is thankfully a living, growing, changing language.

it could be amps per hour soon

[Loafer]

it could be amps per hour soon

 

I doubt it - it'll still be 'wrong'! Most other so-called 'language progression', such as split infinitives, use of comma before the word 'and', over-use of 'like' etc, are all entirely debatable and could soon be considered 'correct' English usage, although I rue the day.

 

The easiest way to think of it was mentioned above by someone who knows, where he compared it to your speed. That is, it is only applicable THIS INSTANT.

 

I can be doing 40 mph, but if I'm driving for 6 hours, I don't end up at 240mph - I'm STILL doing 40mph, but will have covered 240 MILES.

[Murflynn]

I used to lust after silicon NPN transistors

each to his own

[WotEver]

... use of comma before the word 'and'...

... is not necessarily incorrect. In fact, if the 'and' comes at the end of a list, it's essential to give equal emphasis to all of the objects in the list.

 

"John walked down the hill, and he was tired" is incorrect.

 

"Walking down the hill came John, Jill, Jack, and Jim" is not incorrect.

 

Tony

[sjc]

when OC71 / 2s were about the best you could buy (I still have an OC72 I purchased that cost 17/6 and came with 2" leads packed in an individual cardboard box) I used to lust after silicon NPN transistors but couldn't afford them for a long time. I can assure you that Wireless World / Practical Wireless

were full of circuits drawn in this fashion. I certainly had a couple of textbooks on electronics using this method.

Someone told me if you scrape the coating off an OC71 you then had an optical sensor / switch. I never tried it but if you have any left perhaps you could, then let me know if it is true !

[WotEver]

Someone told me if you scrape the coating off an OC71 you then had an optical sensor / switch. I never tried it but if you have any left perhaps you could, then let me know if it is true !

Yes, it's true.

 

Tony

 

It was only a thin, pretty brittle coat of black paint.

[Loafer]

... is not necessarily incorrect. In fact, if the 'and' comes at the end of a list, it's essential to give equal emphasis to all of the objects in the list.

 

"John walked down the hill, and he was tired" is incorrect.

 

"Walking down the hill came John, Jill, Jack, and Jim" is not incorrect.

 

Tony

 

 

I'm tending toward disagreement there, Tony. I think it should read:

 

'Walking down the hill came John, Jill, Jack and Jim'

 

Mind you, it was many years ago when I thought I learned that!

[John V]

Someone told me if you scrape the coating off an OC71 you then had an optical sensor / switch. I never tried it but if you have any left perhaps you could, then let me know if it is true !

 

some of the earlier OC71's may have painted black but the later ones and the OC72's and OC 73's had a metal case but if you carefully teased it off you found a glass case underneath (no paint scraping required ) OC44's and OC45's were better choices they were always painted

 

eta yes indeed it was true , the "proper" photo transistor was the OCP71, an OC71 with clear gel as opposed to the normal opaque white filler which made it more sensitive

Edited February 19, 2016 by John V

[Murflynn]

... is not necessarily incorrect. In fact, if the 'and' comes at the end of a list, it's essential to give equal emphasis to all of the objects in the list.

 

"John walked down the hill, and he was tired" is incorrect.

 

"Walking down the hill came John, Jill, Jack, and Jim" is not incorrect.

 

Tony

.... afraid you are absolutely wrong.

 

the comma is never used in a list in conjunction with 'and' as in the second instance.

 

the comma should be used to indicate that the actions are entirely separate as in the first instance.

[Paul C]

... is not necessarily incorrect. In fact, if the 'and' comes at the end of a list, it's essential to give equal emphasis to all of the objects in the list.

 

"John walked down the hill, and he was tired" is incorrect.

 

"Walking down the hill came John, Jill, Jack, and Jim" is not incorrect.

 

Tony

 

Use of a comma before "and" isn't necessarily correct but there's cases where its exclusion (or inclusion) can add or remove ambiguity. Have a look at https://en.wikipedia.org/wiki/Serial_commaif you're really interested!!

.... afraid you are absolutely wrong.

 

the comma is never used in a list in conjunction with 'and' as in the second instance.

 

the comma should be used to indicate that the actions are entirely separate as in the first instance.

 

Oxford and MHRA would disagree with you.

[WotEver]

 

 

I'm tending toward disagreement there, Tony. I think it should read:

 

'Walking down the hill came John, Jill, Jack and Jim'

 

Mind you, it was many years ago when I thought I learned that!

Yeah, that's exactly what I was taught but... I had the same conversation with an English Language university lecturer about 20 years ago and he said "You never studied English Language past 'O' Level, did you?" He then went on to explain the importance of the comma at the end of a list. How you wrote it (without the comma) gives special emphasis to Jim.

 

So he said.

 

So, it appears that the "no comma before a conjunction" rule is almost as useless as the "I before e except after c" 'rule'.

 

(note I used no comma before the but... )

 

If you can be bothered (I have to admit that I haven't) there's loads of reading on the subject here: http://www.grammarerrors.com/resources/

 

Tony

[RLWP]

How many roads must a man walk down?

 

Richard

[WotEver]

.... afraid you are absolutely wrong.

 

the comma is never used in a list in conjunction with 'and' as in the second instance.

 

the comma should be used to indicate that the actions are entirely separate as in the first instance.

Sorry but you are incorrect as previous posts have pointed out.

 

Tony

How many roads must a man walk down?

 

Richard

He will start with s single step.

[Loafer]

Fairy nuff!

 

I was limited to O level, too.