Re: Voltage determination

["Malcolm Watts" <M.J.Watts-at-massey.ac.nz> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

On 22 Jul 00, at 11:26, Tesla list wrote:

> Original poster: "Barton B. Anderson" <tesla123-at-pacbell-dot-net> 
> 
> Hi Jim, All, 
> 
> Agree about the needle and ROC situation, but I'm not sure about the
30kV/cm. I
> have no idea what it is but I'm starting to wonder if this value varies. I've
> seen this value used (and several others). In the archives, I read a 1998
post
> from Bill Wysock stating that 13M "may" be around 8kv/inch (or near) and that
> the output voltage was about 1/3 less than originally thought. This was based
> on an IEEE paper he was reading at the time which appeared to leave an
> impression on him. 
> 
> I'm not sure if Bill remembers that one, but it did start me pondering that
> possibly a volts/unit value may change with coil power, dimensions,
> environments, etc. If it does change, then is it too much to use a standard?
> Maybe it doesn't - I don't know. 
> 
> I'm curious if anyone else has insight on the subject. Is there a consensus? 
> 
> Thanks, 
> Bart 
<snip>

hi Bart,
         I think there is a sparklength dependency on voltage 
but equally there is one dependent on available charge and in 
the case of a TC, there is a repetition factor as well. 
Consider a lightning bolt which travels far further than the 
voltage estimates of a few tens of MVs that I have seen would 
suggest. 
      For a TC, run it up from 1BPS to ? and watch the sparks 
grow. It may be impossible to point to one element alone (e.g. 
voltage) and say that it is resonsible for a certain length of 
spark since it won't get very far if there is no substantial 
source of charge to back it up.

Regards,
Malcolm