Re: Addendum-DC Tesla

To: tesla-at-pupman-dot-com
Subject: Re: Addendum-DC Tesla
From: Richard Hull <hullr-at-whitlock-dot-com>
Date: Wed, 07 Aug 1996 20:08:44 -0700
Tesla List wrote:
> 
> >From NTESLA1-at-VM.SC.EDUTue Aug  6 20:29:51 1996
> Date: Tue, 06 Aug 96 11:25:08 EDT
> From: Dan Kline <NTESLA1-at-VM.SC.EDU>
> To: All <tesla-at-PUPMAN.COM>
> Subject: Re: Addendum-DC Tesla
> 
> I'm sure I'm not the only one to notice this, but...;)
> 
> >> Sure it's rectification due to dissimilar electrodes.  You can
>                                   ^^^^^^^^^^^^^^^^^^^^^
> >> charge a capacitor with DC from a spark coil if you use such
> >> electodes, for example a disk and a needle, and play with spark
>                             ^^^^^^^^^^^^^^^^^
> >> length.  I think that's why you get the "jolts" off the TC.  When
> >> the fatter and continuous sparks occur I think there's enough
> >> ionization present to nullify any significant rectification.  I
> >> get plenty jolts even off my little coil run from 12 V ignition
> >> COIL!
> 
> >I really doubt if dissimilar metal make a difference.  My experiments all
> >use aluminum-aluminum!  I have nevr used dissimilar metals in my DC work
> >to avoid just such a suggestion.
> 
> Sounds more like dissimilar *shapes* to me. ;)
> 
> So, does the shape difference in the electrodes rectify because of damping
> of the pulse vs. ability of the disk-electrode to discharge, or is it something
> else? I would like to know more about this phenomenon anyway. And as far as
> Ion-charge around the toroid is concerned, that sounds like a compression wave
> is forming because of exponential decay of the output. No matter what, there's
> going to be a residual charge, right? And this is added to with every pulse
> is it not? Just guessing though...;)
> 
> Dan Kline  <ntesla1-at-vm.sc.edu>


Dan, 

Most of your thoughts are in line with mine.  I mis-understood and or 
misread Ed's original post.  I though he meant dissimilar metals when, 
indeed he meant dissimilar shaped electrodes.  The optimum emitter 
electrode in a sharp point and the best collector electrode is a sphere 
or special hemisphere.  I have tried flat aluminum plates from sheet 
stock and they actually work almost as good as the sphere, although their 
top voltage is limited by corona.  Under 10,000 volts though, they are as 
good as the smoothest sphere!!

Richard Hull, TCBOR