Re: Subject Re: DRSSTC Tuning and Split Frequencies of Dual coupled system

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Jared,

Is this Lagrange's "method of variation of parameters". I can find so 
little about it.

Gerry R.


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Wednesday, April 19, 2006 12:32 PM
Subject: Re: Subject Re: DRSSTC Tuning and Split Frequencies of Dual 
coupled system


> Original poster: Jared E Dwarshuis <jdwarshui@xxxxxxxxx>
>
> Hi: Robert
>
> I will show a simple example. We want to find the frequency of a
> series LC circuit.
>
> We define:      La = potential - kinetic
>
>                 La = 1/2 L I(sqrd) - 1/2 1/C Q(sgrd)
>
>
> Set the partial derivitive of La with respect to Q to equal the
> negative derivitive with respect to time of the partial derivitive of
> La with respect to current.
>
>
> Then:           L dI/dt + Q/C = 0
>
> Let:            Q = a cos wt
>             dq/dt = -w sin wt
>             di/dt = - w(sqrd)Q
>
> then:       w(sqrd) = 1/LC
>   or:       w = 1/ sqrt(LC)
>
> The variational methods fell out of favor long ago when they got
> linked to mysticism. Nontheless both Maxwell and Shrodinger used them
> extensivly. Wish I had time to play around with this stuff so I could
> give you the solution. But at the moment I have other projects to
> finish so it goes on the back burner.
>
>
> Sincerely: Jared Dwarshuis