Body
Thank You Ole for that very informative piece on Tesla's early
understanding of the transmission line theory. The first brush that I
had with this idea was when I read Margarett Cheney's book Man Out Of
Time, where Tesla was demonstrating this with an incandescent bulb
sliding along a long copper bar fed with high freq AC. The bulb would
light at the nodal points along the bar. Thank You again Ole for an
excellent piece.
On 7/8/2018 8:34 PM, [email protected] [EVGRAY] wrote:
>
> "Remember when Tesla demonstrated extracting energy at the nodal points
> on a copper bar conductor??"
>
> With the return path of the current it is a transmission line or a one
> turn coil. Thinking in DC circuits a copper bar is a short after the
> initial transient pulse or just a good conductor having almost the
> same tension all along its length. In AC circuits of high frequency or
> in pulsed DC circuits of high frequency the waves are shorter than the
> length of the copper bar as the velocity of the waves prevents a pulse
> or wave to reach the opposite end before the next pulse or wave is
> transmitted.
>
> Tesla - On Light and Other High Frequency Phenomena - Figure 19-183.gif
> Source:
> https://en.wikisource.org/wiki/On_Light_and_Other_High_Frequency_Phenomena
>
> In the above figure of Tesla's experiment B and B' are the copper bars
> forming a transmission line. The reflections are different for shorted
> and open ends. A shorted end gives inverted voltage reflections while
> an open end gives inverted current reflections. When the load at the
> far end (top) is of the same impedance as that of the transmission
> line there will be no reflection from this end as all power reaching
> that far is then absorbed. The other loads can still reflect some of
> the signal if not impedance matched to the transmission line impedance.
>
> An analysis on this experiment:
> https://waveguide.blog/brief-history-tesla-hairpin-circuit-stout-copper-bars/
>
> Reflections on an open ended transmission line:
> http://emlab.utep.edu/ee4347appliedem/TLStandingWave_open_logo.gif
>
> http://emlab.utep.edu/ee4347appliedem/TLStandingWave_open_logo.gif
>
> Reflections on a shorted end transmission line:
> http://emlab.utep.edu/ee4347appliedem/TLStandingWave_short_logo.gif
>
> http://emlab.utep.edu/ee4347appliedem/TLStandingWave_short_logo.gif
> The green waves are the forward waves from the generator and the gray
> waves are the reflected waves. The red and blue standing waves are the
> resultant waves formed by superposition of the forward and reflected
> waves. By placing a load between the voltage and current notes power
> can be transferred to that load if it is of proper impedance as shown
> by Tesla.
>
> For more animations of transmission lines go down to *Topic 4 --
> Transmission Lines* here: http://emlab.utep.edu/ee4347appliedem.htm
>
> Regards
> Ole
>
>
>
>
> ---In [email protected], <nwootan@...> wrote :
>
> Remember when Tesla demonstrated extracting energy at the nodal points
> on a copper bar conductor??
>
>
> On 9/17/2011 2:44 PM, Jim Warren wrote:
> > Norm
> >
> > ��� Do I have it thgether now?
> >
> > Jim
>
>