Re: How long? (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sun, 5 Aug 2007 08:25:47 -0600
From: Gomez Addams <gomezaddams@xxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: How long? (fwd)


On Aug 4, 2007, at 9:11 PM, Tesla list wrote:

>
> ---------- Forwarded message ----------
> Date: Fri, 3 Aug 2007 21:49:28 -0700
> From: Anthony R. Mollner <penny831@xxxxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: How long?
>
> I was wondering if anyone in the group can give some kind of  
> indication of
> how long is safe to run a coil. I am referring to the durability of  
> a static
> gap compared to a SRSG, not to mention the ratings on the  
> capacitors? How
> about between running with or without a terry filter or chokes? Any  
> of the
> frailties that might kill a coil. How long do most of you run your  
> coils at
> one time, 3- seconds, a minute, five even? These tungsten rods  
> should be
> able to just run and run for hours. Comments?

Assuming your capacitor(s) is/are sufficiently robust, it comes down  
to the ability of your particular spark gap to dissipate heat  
effectively.  The maximum I ever ran a large-ish (12kW) coil was  
about 5 minutes continuously, when Starz Film Channel shot one of my  
coils in our haunted house operation for a commercial (Halloween  
horror film series).

That was also the only time I ever saw (in person) the phenomenon of  
a thick, bright white, slowly undulating "power arc" slowly growing  
outward from the toroid, terminating in the usual branching brush  
discharges at the end.  At the time, I attributed this phenomenon to  
the small aluminum tape break-out point I'd placed on the toroid as  
well as the completely still air of the indoor environment.

Sadly, my boss managed to lose the only copy we received of that  
footage, one of the many crimes for which I never forgave him.  It  
was quite the impressive shoot, given that it was only for a 30- 
second cable TV spot.  Steadicam, large crew, catered...

*sigh*

That was the third time that quality video footage of one of my large  
coils running really well has been lost.  Naturally, I have plenty of  
footage of large coils running poorly!

But I digress.

If your spark gap is conservatively designed for your power level and  
your capacitors are of high quality, there is no reason you shouldn't  
be able run almost indefinitely.  I believe I have read posts from  
other coilers here claiming runs of 10 minutes or more.

  - Gomez


.....................................................
A long memory is the most subversive idea in America.