Retired Railroader Explains Easiest AC Circuit Theory

[TedA]

I am retired from a major railroad co. where I worked on electronic weighing equipment. I have an associate of applied science degree from a local university. I have a basic understanding of dc and ac electricity but the explanation I recently read on this forum was the easiest to understand that I have seen. However I feel it would be an improvement if the actual circuits referred to could be drawn along with the text. I am referring to the explanation of the relationship of AC neutral and ground circuits using a dc flashlight with two batteries and a ground or neutral connection between the batteries.

 

[Drakkith]

However I feel it would be an improvement if the actual circuits referred to could be drawn along with the text. I am referring to the explanation of the relationship of AC neutral and ground circuits using a dc flashlight with two batteries and a ground or neutral connection between the batteries.

What do you mean? Are you referring to a specific post, or in general, or what?

 

[Borek]

If you have a spare moment to draw the circuit - please do, save it as an image (if done on computer gif or png format, if by hand and scanned, jpg - but with so many free CAD programs I wouldn't bother with paper) and then post it in the thread (upload as an attachment to the post).

 

[jim hardy]

I am referring to the explanation of the relationship of AC neutral and ground circuits using a dc flashlight with two batteries and a ground or neutral connection between the batteries.

If you can find that post and click on its number

you'll get something like this

copy and paste that address in the orange box , it'll let us see what post you are referring to.

old jim

 

[Nidum]

This one possibly : ?

Alternating Current, live and neutral wires
Here's the script i use The humble flashlight has a lot of lessons in it. Get yourself an old fashioned two cell metal one to use for a prop...
Post by: jim hardy, Nov 6, 2016 in forum: Electrical Engineering

https://www.physicsforums.com/threa...t-live-and-neutral-wires.892309/#post-5613568

 

[jim hardy]

I think i remember that one. I don't think i drew any pictures for it though. Paint is what i use when i do,
That's the thread where a teacher asked for suggestions how to teach the concept . I gave verbal instructions how to draw some visual aids and suggested an outline that I've used with some success. .Don't know why i didnt draw him a picture for by that time i'd learned to use Paint.. But we never heard back from him..

Seems to me we had several threads with good images courtesy dlgoff and The Electrician others. One of Don's always on target pictures is in the thread Nidum mentioned.

 

[jim hardy]

I am retired from a major railroad co

Union Pacific by any chance ?

 

[Shaneyj]

I think i remember that one. I don't think i drew any pictures for it though. Paint is what i use when i do,
That's the thread where a teacher asked for suggestions how to teach the concept . I gave verbal instructions how to draw some visual aids and suggested an outline that I've used with some success. .Don't know why i didnt draw him a picture for by that time i'd learned to use Paint.. But we never heard back from him..

Seems to me we had several threads with good images courtesy dlgoff and The Electrician others. One of Don's always on target pictures is in the thread Nidum mentioned.

Jim Hardy, I am a 6th year (senior level... takes longer when you're old) electronics engineering technology degree major. I'm also a 20 year electrician.
That flashlight post was the most compelling, and more importantly in my opionion, the simplest comprehensive introductory explanation of electricity I have seen.
And I think I'm uniquely qualified to say that because I have to read/watch/listen to the same concept explained 10 different ways in order to get a grasp of it.

 

[jim hardy]

Jim Hardy, I am a 6th year (senior level... takes longer when you're old) electronics engineering technology degree major.

Well THANK YOU Shaneyl for your kind remarks. Helps an old guy feel useful .

I see that's your first post - Welcome to Physics forums. It's an amazing place.

old jim .

 

[TedA]

To Drakkith: Yes I am referring to a specific post. In general, an explanation that refers to specific circuits should illustrate the circuits.

To Jim Hardy: I am retired from CSX. We only know how to railroad east of the big river.

TedA

 

[jim hardy]

To Drakkith: Yes I am referring to a specific post. In general, an explanation that refers to specific circuits should illustrate the circuits.

To Jim Hardy: I am retired from CSX. We only know how to railroad east of the big river.

I don't quite remember why i didn't make drawings to go with the 'essay' i wrote , the one @Nidum linked.. Seems i felt the guy needed an answer quickly for he said in his initial post

I am a teacher and will be teaching the topic of alternating current soon.

and it takes me hours to draw stuff in "Paint" . So i dashed out that essay in a hurry, trying to paint vivid word pictures he could embellish and get it out quickly for him.
We never heard another peep from him so i figured i'd bombed with the educator audience. And there were no further posts after second day. But four PF regulars 'liked' it .

If that's the thread you're referring to, thanks for your interest in it . I see it's still open so feel free to add to it. Use the "quote" feature or copy&paste (ctrlC ctrlV or highlight & rightclick) . I could probably work up some illustrations if you guys think it might help somebody.

 

[jim hardy]

To Jim Hardy: I am retired from CSX.

I co-op'ed briefly in mid 1960's for Mo-Pac communications dep't replacing hand-crank telephones with dial systems.

 

[TedA]

To Jim Hardy: Yes I think drawings would help students visualize the concept of the electron flow in the circuit. I made my own drawing on scratch paper to help me figure it out. It is really a simple concept once you figure it out. I worked on electronic weighing equipment for CSX for 30 years.

TedA

 

[jim hardy]

It is really a simple concept once you figure it out.

Hmmmm Indeed it is. And there are a LOT of misconceptions out there.

We have here on PF a place called "Insights" where people explain things in their own words. I had considered this so basic it'd be presumptuous of me to offer it there. But your interest, and shaneyi's cause me to wonder - maybe it could serve as an 'electricity for non electrical people' primer ?

I'd want to add a section about electric fields and explain why we don't really have to think much about them for basic circuit analysis , but must be aware that electrodynamics exists and it's the basis from which all our thinking starts.

Would you take a look at these two posts and let me know if you think they'd be of help to the audience we have in mind ?
https://www.physicsforums.com/threa...fference-vs-voltage-drop.741405/#post-5331150
https://www.physicsforums.com/threa...s-on-an-empty-wire.903244/page-2#post-5688002old jim

 

[Borek]

I had considered this so basic it'd be presumptuous of me to offer it there.

Calling @Greg Bernhardt

 

[Windadct]

The challenge is different people learn in different ways, some like words, some like diagrams and some like maths ( today - I have to say some like simulations - while this may prove something ( not really) - IMO it does not really lead to understanding ... Unfortunately here at PF the Original Posters (OPs) often are "passers through" and never even respond, so it is hard to get the type of detail you are asking for - but I agree, for a lot of what is discussed here, a diagram is yugly valuable. Next - real links to content they are asking about...

As for you rail peeps - a LPT... buy one share of UP Stock, and you get a nice calendar every year..(I have a 2018 available if someone will pay postage)

 

[dlgoff]

We have here on PF a place called "Insights" where people explain things in their own words. I had considered this so basic it'd be presumptuous of me to offer it there. But your interest, and shaneyi's cause me to wonder - maybe it could serve as an 'electricity for non electrical people' primer ?

bold by me

I could probably work up some illustrations if you guys think it might help somebody.

Go for it Jim. I think that would be a really useful "Insights" article.

 

[jim hardy]

Thanks guys , i will do that. old jim

 

[TedA]

To Jim Hardy: I did not really care for the two posts you asked about. To much talk about "potential". To me potential difference just means possible difference. There are many possible voltage differences in any complex circuit. This is why we have to define our point of reference before any of this makes any sense. Of course this point of reference is usually ground or the common point where all current tries to get to in a circuit. What I really liked in your flashlight explanation was the way you explained the concept of "ground" and the fact that all current does not 'want to get to ground". It cannot flow through to ground unless there is a way to get back to the origin point. If you want to talk about the voltage "drop" across a load then you should include ohms law so the the relation between voltage, current and resistance can be understood.

 

[jim hardy]

Thanks for the feedback and clarifications.

""potential difference just means possible difference"" is certainly a grammatically correct statement . Not sure whether it tells me i need to plant the physics convept of 'potential' as work/energy early on in this essay or save it for another one.. Thanks Ted ! old jim