Re: High Voltage (fwd)

[Pete Lohstreter <petel@tenet.edu>]

On Wed, 24 Sep 1997, Lowell Herr wrote:

> 	I have a question I haven't been able to find a satisfactory answer to, 
> but thought you might be able to help.
> I build a Tesla Coil high voltage generator over the summer and want to 
> measure the output voltage.  I have read that a) voltage affects spark length 
> only and b) power output affects spark length.
> Is their any way to relate output voltage to spark length?  I get 18" sparks.  If I use spark length as an indicator,
> this would be 18" * 32000 V/inch = 576000 volts.  Is this correct? 
>
> 	Sincerely,
> 				Brian Knight

As I understand it, it is the potential that produces the spark.  The
power  (volts times amps) is responsible for the heating and most likely
the brightness of the spark.  The conditions of the air tend to change the
breakdown voltage and some compensation for humidity, air pressure and
temperature must be made.  However, you are correct about the 'rule of
thumb' approximation of 30,000 V/in  or 10,000 V/cm.   In any event,
500,000 Volts is impressive.

Pete Lohstreter
petel@tenet.edu
North Garland High School
Garland, TX