Re: Rotary Spark Gap Design

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Harold Weiss" <hweiss@xxxxxxxxxx>

Hi,

I'll second that, and add that plywood glue is conductive.  I've had tracks
form right down the glue lines in plywood.  And that was at 3KV to ground.

David E Weiss

> Original poster: "Dr. Resonance" <resonance@xxxxxxxxxx>
>
>
> 440 VAC won't be enough to operate your sparkgap.  You do need a NST is
you
> are running a classic HV circuit and not SSTC.  The lowest reliable
> potential is 3 kV min.
>
> Don't use a wooden disk.  Most wood contains some moisture (3-5%) and will
> not hold off the high voltages -- especially RF voltages which like to
track
> across surfaces such as wood.  Or, worse, it might start smoldering
> internally.  Then, you shut off the lights, go to bed, and wake up to
> discover your shop or home on fire.  Use type CE or LE phenolic or G-10
> phenolic plate for the rotor.
>
> Be safe!!
>
> Dr. Resonance
>
>  >
>  > Dear forum members,
>  >
>  > I'm planning to build a rotary spark gap:
>  > 8 spinning electrodes mounted on a wooden disc,
>  > 2 stationary electrodes,
>  > brass bolts used as electrodes.
>  >
>  > I have seen in some Tesla coil designs that the AC input voltage is
> stepped
>  > up to few kilo volts
>  > (using NSTs/PolePigs), rectified and then fed to the tesla coil circuit
>  > that is using the spark gap.
>  > Can I run the tesla coil without stepping up the AC input voltage ? I'm
>  > planning to use
>  > 440VAC input, rectify it and then feed this DC voltage to the tesla
coil
>  > circuit which uses a
>  > rotary spark gap. Any advice ?
>  >
>  > Thanks in advance,
>  > Rajesh.
>  >