Re: question about driving a DC sync spark gap

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "S&JY" <youngsters@xxxxxxxxxxxxxxx>

Miles,

I also use a DC motor with my async RSG.  I have had no problems with the
bridge rectifier, which is only rated for about 10 amps.  I think perhaps
the secret is to mount your bridge rectifier and filter cap adjacent to the
motor so that connecting wires are only a few inches long and cannot pick up
any significant RF or other nasty impulses.  Then feed AC from your variac
to your rectifier/filter/motor through your 10 or 20 ft power cable.

So far, with six foot streamers flying around, this works fine without any
filtering of the AC power cable.
--Steve Y.

> ----- Original Message -----
> From: "Tesla list" <tesla@xxxxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Sent: Wednesday, October 11, 2006 11:08 PM
> Subject: question about driving a DC sync spark gap
>
>
>  > Original poster: "miles waldron" <mileswaldron@xxxxxxxxxxx>
>  >
>  > Dear All,
>  >
>  > Is anyone using a DC motor to drive an async rotary spark gap? If
anyone
> is
>  > doing this, how is your variable DC power supply built? We are having
>  > consistent CATESTROPHIC failure of the power supply diodes. Not the
motor.
>  > The motor is always fine, and the variac is always fine. We are using
huge
>  > giant diodes (300V @400A) and they are frying instantly. We have tried
>  > chokes in series, caps in parallel, caps in series, but nothing seems
to
>  > help.
>  >
>  > Please help before we shoot the DC motor with a 1000 watt CO2 laser,
and
>  > rebuild our spark gap using a variable AC motor.