Talk:Hydraulic analogy

Goal

This site says: "Many writers eventually resort to some kind of water analogy to try to explain how electricity works. I have yet to see what I thought was a really good water analogy. If you want to explain electricity, talk about electricity. Hydraulics is another field entirely. Avoid this trap; it is already full."

Although I agree that most such analogies are done poorly, the potential exists for a perfectly accurate one, as they are both fluids flowing down conduits. I hope to make a page for the wikipedia that collects these ideas together into a coherent whole that the naysayers and nitpickers can then edit to perfection. - Omegatron

So I had this in my user space until it evolved into something vaguely encyclopedic, and then merged it with the pre-existing article which was just a table of related equations. Now that it is in the main article space it should evolve a lot faster. - Omegatron 02:48, July 12, 2005 (UTC)

Already I can see problems because the links are taken from websites that don't appear to be credible. If anything, they appear to be the incoherent jibberings of clueless amateurs. Take for example how pressure is equated with voltage. I'm afraid this doesn't make sense to me since pressure is what moves the liquid and so would be better equated with the electrical field since this moves charge. Secondly, unlike pressure, there is no such thing as voltage existing at a point. Voltage measures the energy gained or lost when charge moves between points and so is always referenced to two points. If you want a hydraulic analogy of voltage, then this will have to be equivalent to the energy lost or gained when a certain volume of water is transferred between two points. i.e. the change in (KE + PE).

Cdang's version

it helps a lot understanding the difference between potential and voltage:
- potential → altitude, or pressure;
- voltage → difference in height between the top and the bottom of the water circuit (height of the water column), or difference of pressure between upstream and downstream;
parallel components can be compared with communicating vessels (same voltage~same difference of pressure) and with a flow derivation (Kirchhoff's current law);
What do you mean by "communicating vessels"? - Omegatron
resistance can be compared with friction (loss of charge, pressure drop):
- resistance of the wire → friction in the pipe;
- resistor → sinuous pipe such as heat exchanger;
load of an active component (e.g. charging accumulator, motor, electrolysis) can be compared with a watermill or a turbine;
- back electromotive force → force used to make the turbine turn.

Unfinished

Moving some things here so that I can turn this into a real article:

Transformer: like an AC piston that moves back and forth, connected externally to another such piston by a lever with a pivot in the middle. the amount of lever on each end determines the ratio, and it can only transfer AC. (of course DC at that point in the circuit would change something? hmm... [No, it only works with AC, since a transformer pretty much works by one "inductor" affecting another]). This is similar to a hydraulic transformer. A "fluid coupling transmission"?

I hope to make a better version of this

Original talk page

I have started this article independently. :-) They will be folded together when it is ready. See User:Omegatron/water analogy - Omegatron 21:42, May 24, 2005 (UTC)

Should this be renamed Hydraulic analogy to electric circuits? - Omegatron 21:42, May 24, 2005 (UTC)

Oh I see there is a heat analogy, too. Hmmm... - Omegatron 21:46, May 24, 2005 (UTC)

I look forward to seeing this article made more complete. The heat analogy is very important historically and I think it should remain in the article and linked to Caloric theory. That being said, I think the analogy for heat is less perfect--I don't know of a thermal equivalent of a transistor, for instance, so it makes sense to me to go into more detail with the hydraulic-electric pair. --Scentoni 06:32, 25 May 2005 (UTC)[reply]

Hmmm... maybe keep the article name "Hydraulic analogy", and have a section for electrical analogy and a small section for heat analogy at the end? - Omegatron 13:50, May 25, 2005 (UTC)

Botched merge

So I attempted to merge my userfied version with the actual version, but accidentally moved the talk page over top of the article instead of the talk page, undeleted the old history before I realized it, blah blah etc. Anyway, the end result is that some of the original article's history is now in the talk page history. Sorry. All the info's still there, but it is for the wrong page. - Omegatron 02:42, July 12, 2005 (UTC)

Rectilinear transformer

http://virtual.cvut.cz/dynlab/courseModeling/node42.html

Failures of the model

I've added a section about the limits of the analogy. (Useful analogies can lead to serious misconceptions when we don't know when to drop them, and instead use a better model.)