Talk:Capacitor-spring analogy

Same as System equivalence?

The articles Capacitor analogy and System equivalence seem to talk about the same subject. Merging these articles might give a clearer overview of this topic. EverGreg (talk) 21:08, 1 July 2009 (UTC)

It seems like a good idea to me. If we have Capacitor analogy we should also have Inductor analogy and Resistor analogy. To be understandable each article will have to explain the whole analogy, so why not explain it all in one place? Another issue, not addressed in this article, is that there are actually two ways to draw an analogy between mechanical and electrical circuits, corresponding to series- and parallel-resonant circuits:

Mechanical	Series RLC Circuit	Parallel RLC Circuit
Position $x\,$	Charge $q\,$	Flux linkage $\phi \,$
Velocity ${\frac {\mathrm {d} x}{\mathrm {d} t}}\,$	Current ${\frac {\mathrm {d} q}{\mathrm {d} t}}\,$	Voltage ${\frac {\mathrm {d} \phi }{\mathrm {d} t}}\,$
Mass $M\,$	Inductance $L\,$	Capacitance $C\,$
Spring constant $K\,$	Elastance $1/C\,$	Susceptance $1/L\,$
Damping $\gamma \,$	Resistance $R\,$	Conductance $G=1/R\,$
Drive force $F(t)\,$	Voltage $e\,$	Current $i\,$
Undamped resonant frequency $f_{n}\,$:
${\frac {1}{2\pi }}{\sqrt {\frac {K}{M}}}\,$	${\frac {1}{2\pi }}{\sqrt {\frac {1}{LC}}}\,$	${\frac {1}{2\pi }}{\sqrt {\frac {1}{LC}}}\,$
Differential equation:
$M{\ddot {x}}+\gamma {\dot {x}}+Kx=F\,$	$L{\ddot {q}}+R{\dot {q}}+q/C=e\,$	$C{\ddot {\phi }}+G{\dot {\phi }}+\phi /L=i\,$

This table is from Harmonic oscillator#Equivalent systems so the topic is also covered there. I really think this term capacitor analogy doesn't merit its own article.--Chetvorno^TALK 18:54, 4 April 2015 (UTC)

I think system equivalence is much too general a subject to include such lowly detail as this article. In principle, that article should cover analogies across all energy domains and all the many different bases upon which such analogies can be founded and should discuss them in a very general way. As I pointed out in this edit, the capacitor analogy discussed here forms part of the impedance analogy and would make a much better redirect. Analogies for inductors and resistors are also discussed there.

The second analogy you point to above also already has an article at mobility analogy. Both of these, the impedance and mobility analogies, form part of a wider group of analogies discussed more generally at mechanical-electrical analogies. I was unaware of the existence of the system equivalence article when I wrote this series of three articles so there may be some room for rationalisation, but I don't think any should be merged. Each is a subset at a different level of a broader group and can be handled at an appropriate level of detail. SpinningSpark 23:56, 4 April 2015 (UTC)

Merge to Hydraulic analogy

Why is this a separate article from hydraulic analogy? The article has hardly any information and Hydraulic analogy already has the same information. Would it be okay to redirect this article there? Pinging Spinningspark for 2O. π♂101 (talk) 23:56, 27 August 2014 (UTC)

Representing a capacitor as a spring is a mechanical analogy, not a hydraulic analogy, and it is not described anywhere on the hydraulic analogy page as far as I can see. To be precise, this is the mechanical impedance analogy. I intend to write an article on that one day. There is also a dual mechanical analogy, the mobility analogy, where springs are instead inductors and capacitors are masses. In short, the proposed redirect is inappropriate. SpinningSpark 00:17, 28 August 2014 (UTC)

@Spinningspark: Whoops. I forgot that the other page is not about electronic analogies in general. I fully agree with your reply. Thanks π♂101 (talk) 00:24, 28 August 2014 (UTC)