RE: (Fwd) RE: Longitudinal Waves

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Pete Komen by way of Terry Fritz <twftesla-at-qwest-dot-net>" <pkomen-at-zianet-dot-com>

Dave,

Consider a circuit consisting of a capacitor (F) and an inductor (H)
connected in series with nothing else in the circuit.  Suppose that the cap
is charged to some voltage V (if you want, imagine a switch in the circuit).
The cap has charge Q = F * V and energy J = F * V^2 / 2.  When the switch is
closed the voltage is at a maximum and rapidly falls (based on the resonant
frequency of the circuit) to zero as the current rises to its maximum.  At
this point (1/4 through one cycle), the energy is all stored in the inductor
J = I^2 * H / 2 (I = current)

V = inductance * dI/dt (voltage is inductance in Henries * change in current
With Respect To change in time.  Note that when voltage is zero, the current
is at a maximum but not changing (instantaneous)

At this time the inductor starts to give up energy as voltage builds in the
cap and the current changes more and more rapidly (falling) as the current
flow is opposed by the voltage building in the cap.  Finally, all energy is
transferred to the cap (the voltage is reversed from the beginning) and the
current is zero.  This is the end of the first half cycle.  This continues
until all energy is lost.

Energy is lost in resistance and radiation (is there anything else?).  The
energy lost means a lower voltage in the cap when the voltage is at maximum,
and a lower current when current is at maximum.

If it is damped, the Q of the circuit is low and drop in voltage at each
peak is less. (or there may be no second peak).

As usual, I don't know if this is what you were looking for.

Regards,

Pete Komen

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, February 13, 2002 4:51 PM
To: tesla-at-pupman-dot-com
Subject: RE: (Fwd) RE: Longitudinal Waves

Original poster: "David Thomson by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<dave-at-volantis-dot-org>

Hi Malcolm,

>Having spent half a lifetime repairing oscilloscopes as well as calibrating
them I must strongly disagree with the statements in that paragraph. Bear in
mind that you can invert one channel of most if not all scopes. The fact
that there is no DC shift in a pure sinusoidal waveform when you do that
speaks volumes.

I've been looking for the reference that I derived my information from.  I
cannot find it just yet.

The DC shift has been shown by some experimenters to exist.

The shift was explained just as I am presenting it, that there are two
opposite polarity waves working together.

While we are on the topic, what is the current scientific explanation for
the variation of voltage in a damped sine wave?  What force is believed to
determine when the wave will reverse direction?  I could use a little
education on the current theory if you would indulge me.  I believe this is
useful information for Tesla coils in general.

Dave