Re: Maxwell Pulse Capacitors

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Tesla729-at-cs-dot-com>

In a message dated 5/6/01 8:14:45 PM Central Daylight Time, tesla-at-pupman-dot-com 
writes: 

Steve White writes: 

>
> More preferable to me are used caps taken from X-ray machines. 
> How many X-rays can be taken in a day. 100? Even if the X-ray machine were 
> used for 10 years, there would still be a lot of life left in the cap. 



Bert Hickman writes: 

< Most low duty cycle applications  such as 
< defibrillators, X-Ray filter cap, Marx generators, HV DC power supply 
< filters, and industrial pulsed welders typically (but not always!) use 
< Mylar caps.   

Hi Steve, Bert, all, 

I've gotta go with Bert on this one. Although x-ray caps are exposed 
to a very low duty cycle in normal operation, they are usually of a 
Mylar dielectric, since they are designed strictly for filtering service. 
I've torn into an x-ray filter cap before and it is NOT of the extended 
end foil construction and the terminations are quite wimpy. Obviously, 
it wouldn't hold up well in Tesla service. 

But again, Steve has also got a point in that one dosen't know how 
much use a used cap has seen when they get it.  However, most caps 
that are designed for lasers are designed for the rapid charge/discharge 
duty which would render them more suitable for Tesla duty. So, I believe 
the laser Maxwell caps are more likely to have the polypropylene dielec- 
tric, which has very low RF dissapation, which is what we want :-) 

Sparkin' in Memphis, 
David Rieben