Re: "plate" capacitors

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

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

In a message dated 4/17/01 10:16:06 AM Eastern Daylight Time, 
tesla-at-pupman-dot-com writes: 


>
> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <A123X-at-aol-dot-com
>
> > 
>
> Its just that the MMC costs way more than the homemade plate caps. 



        If you rate the caps at $/MTBF (mean time between failures), or 
total cost per year of service, rather than just initial dollars, I don't 
think the above statement is always true. Low cost, short-lived, high 
maintenance items are seldom a bargain unless you are passing them off to 
someone else. 
        A few years ago, I was in charge of maintaining a facility (a new 
church) where capital costs for the initial project were kept low by buying 
cheap materials with low life expectancy. This was done because the 
construction supervisor was responsible for the Capital Budget, not the 
Operating Budget. In three years, my maintenance budget quadrupled. Sometimes 
cheap is very dear. 
        Even if you consider your labor to have $0.00 value, you still have 
to consider the total cost of clean-up and recovery after a catastrophic 
failure. (Cleaning and repairing walls, oil containment and mop-up, oil 
replacement, fixing coil damage, etc.) as part of the cost of a particular 
type of cap. Some people are lucky, they can run for a long time without 
problems, but I think you'll find them the exception. 
        Of course, there are other considerations. I have one tank capacitor 
that is a fish tank full of aluminum and Lucite plates that glows blue in the 
dark. Very inefficient, but it was done purely for the visual effect. I do 
not use it for any serious purposes.