Capacitors, why even bother?


by cpatel23
Tags: bother, capacitors
Greg-ulate
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#55
Dec23-12, 11:21 PM
P: 72
Ratch,

Everyone says Charge interchangeably with Energize in the context of batteries and capacitors... I bet you say "Hey where is my battery charger?" when you need to "Energize" the batteries in your phone or whatever.

Nobody says "I have a capacitor C net charged to V volts and therefore it stores CV^2/2 Joules of energy," so your argument is basically a Straw Man argument. Just because the net charge doesn't change, that doesn't make it wrong to say charged. Current flows out of one leg and into the other, one plate becomes charged with respect to the other plate. Then it stays there. It's stored there. Capacitors store charge.

I noticed that you have argued this point in other instances and while it is technically correct, and everything else you have to say is astute and meaningful in the context of the conversation, arguing this point is not constructive.
Greg-ulate
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#56
Dec23-12, 11:25 PM
P: 72
Quote Quote by Ratch View Post
Surely, you will agree that "energizing" describes it unambigiously.

Ratch
Firing a capacitor out of a cannon would also energize it, so its not any less ambiguous than saying charge.
sophiecentaur
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#57
Dec24-12, 02:51 AM
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We are all aware of this and the term " charge" incorporates this knowledge. Just what is your point? Do you seriously expect to change this established terminology? Don't hold your breath.
Ratch
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#58
Dec24-12, 09:44 AM
P: 315
Drakkith,

You aren't wrong.
Thank you. I wanted to see that.

This isn't about wrong or right, but about personal opinion.
I can't do anything about that.

Greg-ulate,

I bet you say "Hey where is my battery charger?"
I am careful not to say that.

Nobody says "I have a capacitor C net charged to V volts and therefore it stores CV^2/2 Joules of energy," so your argument is basically a Straw Man argument.
No one says "I have a cap C energized to V volts and therefore it stores CV^2/2 joules of energy either, but so what is the point? What does that statement prove or disprove?

Just because the net charge doesn't change, that doesn't make it wrong to say charged
If I have a jar half filled with water, and turn it upside down so that the liquid switches to the top part of the jar, does that mean I filled the jar with liquid?

Current flows out of one leg and into the other, one plate becomes charged with respect to the other plate.
One plate becomes imbalanced with respect to the other plate. Moving a charge is an energy changing operation, not a charging one.

Then it stays there. It's stored there. Capacitors store charge.
If you move the contents of a cupboard from one shelf to the other, you are not storing anything.

...while it is technically correct,...
Thank you. I wanted to see that.

Firing a capacitor out of a cannon would also energize it, so its not any less ambiguous than saying charge.
It would not give the cap any electrical energy, which is what we are talking about.

sophiecentaur,

We are all aware of this and the term " charge" incorporates this knowledge. Just what is your point? Do you seriously expect to change this established terminology? Don't hold your breath.
No, the term charge is a misnomer in this case. As I showed in some examples in a previous post, some folks do use the correct terminology.

Ratch
sophiecentaur
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#59
Dec24-12, 10:32 AM
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@Ratch
You and the others who use your terminoligy are in a minority and your just "goin' on" about it gets you nowhere. That particular expression is dimensionally correct, unlike "volts going through you". "electromotive force" and "electrical resistance tries to stop the current" etc. and, it is perfectly acceptable.
Why waste you time on this when you are demonstrably quite capable of making worth while comments on other topics? You should pick your battlegrounds in places where you have a chance of winning.
Have a stress free and terminology free Christmas. I hope that when you charge your glass with wine, it doesn't discharge out of its other end.
jim hardy
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#60
Dec24-12, 12:57 PM
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ratch wrote
I know of no scholarly article on common sense.
I'll resist the obvious.

Try Asimov, On Physics and View from a Height. And Don Quixote.
the_emi_guy
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#61
Dec24-12, 01:02 PM
P: 580
Ratch,

Give us one example of where the term "charging" would be appropriate usage.
Ratch
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#62
Dec24-12, 04:15 PM
P: 315
sophiecentaur,

You and the others who use your terminoligy are in a minority ...
I would rather be in the correct minority than the wrong majority.

jim hardy,

Try Asimov, On Physics and View from a Height. And Don Quixote.
Fiction writers? By the way, what does "common sense" have to do with this argument? I am either right or wrong. Some of you said I was right even though I should use wrong nomenclature.

the_emi_guy,

Give us one example of where the term "charging" would be appropriate usage.
Ratch

I can't think of any for capacitors, and I have not seen any in the arguments against my position.
the_emi_guy
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#63
Dec24-12, 04:20 PM
P: 580
You can't think of *any* circumstance where you could correctly use the term "charging". We should remove it from our technical vocabulary entirely?
sophiecentaur
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#64
Dec24-12, 05:37 PM
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Ratch
You are losing your Capacity to see reason. That's a chargeable offence, I think. It goes against current thinking and is Potentially troublesome. Why resist? You will feel more at Ohm with things if you conduct yourself better. Your powers of Induction should bring you to a terminal conclusion. Or is it a case of Do or Die - electric?
jim hardy
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#65
Dec24-12, 06:00 PM
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deleted, on second thought...

Merry Christmas to all !!!!!!!!!!
sophiecentaur
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#66
Dec24-12, 06:12 PM
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And to you Jim and all the others
Drakkith
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#67
Dec24-12, 08:30 PM
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Well, I think this thread has run its course...
Ratch
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#68
Dec24-12, 08:34 PM
P: 315
sophiecentaur,

I admit I am biased toward TRUE meaning of words, and not the FALSE impression caused by the time decay of proper usage. The timely constant reminder I give when I talk about misnomers shows my incapacity to conduct myself as though they were never spoken. My inability to go with the current flow is intrinsic within me. For that I apologize.

Ratch
Drakkith
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#69
Dec24-12, 08:48 PM
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There's no reason to be rude.
jim hardy
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#70
Dec25-12, 12:01 AM
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This is what happens when you get your "knowledge" from answers dot com...

http://wiki.answers.com/Q/How_do_cap...store_a_charge

Capacitors don't really store charge at all. They allow negative charge to be transferred from one plate to the other, thus establishing an electric field between their plates. But there is no net increase in charge -the amount of charge on the capacitor's plates, after 'charging', is exactly the same as there was before 'charging' -it's just moved around! What capacitors 'store' is energy, not charge.

Read more: http://wiki.answers.com/Q/How_do_cap...#ixzz2G2TVMN7k

Scholarship on the subject was dismissed in post # 45
I know of no scholarly article on common sense.
and then common sense was dismissed in post # 62
By the way, what does "common sense" have to do with this argument?
Silly me - i came in thinking it was a discussion.
jean28
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#71
Dec25-12, 12:44 AM
P: 86
@cpatel23

Capacitors are great for quick discharges of energy that batteries could only dream of doing. The classical example is the flash of a camera. It would take a battery a long time to discharge the needed energy for the flash, and it would be beyond infuriating to have to wait standing still God knows how long until the camera finally releases the charge.

You will also learn in your electronics course that the Capacitors are also very useful in AC to DC converters because they help reduce the Ripple voltage.

As for the textbook, I highly recommend this one:

http://www.amazon.com/Microelectroni...circuit+design

I used a different one for my electronics course, and honestly speaking I didn't like it too much. It felt too theoretical without enough real life examples to understand what was going on. I will use the one in the link a gave above for my digital electronics class next semester and from what I've seen so far it is much better and easier to read than the one I used.

I suggest reading part one: Solid State Electronic and Devices. Parts two and three are for more advanced courses.

And just in case, this is the book I used for my course:
http://www.amazon.com/Microelectroni...ronic+circuits


If you are going to buy one, then I suggest the first one. If you will get them digitally, try to get both and use them as references.

Cheers.
sophiecentaur
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#72
Dec25-12, 07:23 AM
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Quote Quote by Drakkith View Post
There's no reason to be rude.
I don't think it's rudeness - it is just lack of empathy. Some people just latch on a particular interpretation of an idea and don't see the way the rest of the World (the 'informed' world) view it. They decide that they are 'right' and cannot reconsider. Can be quite a nightmare in personal dealings in the real world. Happily, on a forum like this it doesn't represent a problem.


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