[Prev][Next][Index][Thread]
RE- Test of 6" coil
Subject: RE- Test of 6" coil
Date: Fri, 30 May 1997 16:45:15 GMT
From: robert.michaels-at-online.sme-dot-org (Robert Michaels)
Organization: Society of Manufacturing Engineers
To: tesla-at-pupman-dot-com
I don't know if it's proper netiquette to respond to my own
response, but there's an additional item I'd like to add to
my proposed capacitor FAQ:
- - - - - - - - - - -
It is utterly =crucial= to operate any oil-filled capacitor
in the correct orientation: righsideup, upsidedown, or
sideways. The better capacitors have an arrow or wording
either stenciled or stamped on the case to indicate operating
orientation. Else (sorry about this), you'll just have to
read the manufacturer's spec. sheets or application notes.
IMHO -- It's not a good idea to even store oil-filled capacitors
in the wrong orientation for protracted periods, but that's just
my gut feeling.
=Still= charged-up, in --
Detroit, USA
Robert Michaels
-> Hate to make you the target of my ire, Ed (especially you),
-> but I see this same foggy-bottomed thinking again, and again
-> (and again!) on This List:
-> -- If a capacitor is rated "X-volts, ac" that is r.m.s. volts
-> and =not= peak volts! So your 20,000-v. capacitor is
-> good for 14,144-v. ( that's 20,000/1.414 ) -- but not
-> quite.
-> -- Capacitor manufacturers have =forever= played fast and
-> loose with voltage specs. It is therefore =essential=
-> to de-rate mfg'rs. specs. before applying any capacitor.
-> (One sees the same thing in other areas of industry --
-> auto makers' horsepower specs., for instance.)
-> With this in mind, any working engineer would not
-> apply the above capacitor at any voltage, over, say
-> 10,000-v r.m.s. The difference between 14,144
-> and 10,000 is a very necessary safety factor.
-> | At =best= the spec. plate voltage |
-> | of a capacitor should be take as its |
-> | never-to-be-exceeded voltage, not |
-> | its day-in/day-out working voltage! |
-> -- In a Tesla circuit, rife with inductance and sparking,
-> there are certain to be transient voltage spikes which
-> rise well above the normal ac peak.
-> With this in mind, your capacitor probably should
-> not be used in any Tesla circuit over, say,
-> 5,000-v ac. This done, your capacitor would have
-> probably lived forever (all right, for quite some
-> years).
[ ... ]