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From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: sci.electronics
Subject: Re: Spark Coils
Summary: No longer very common...
Message-ID: <3829@kitty.UUCP>
Date: 4 Jul 90 01:21:50 GMT
References: <9007032018.AA27882@ucbvax.Berkeley.EDU>
Organization: Recognition Research Corp., Clarence, NY
Lines: 39

In article <9007032018.AA27882@ucbvax.Berkeley.EDU>, rats@ihuxz.UUCP writes:
> Are spark coils still manufactured? I don't mean the little Model-T
> 1/2" jobs, I mean the big ones which give sparks 2" or greater.

	Induction coils of the type you describe have not been used in
probably 50 years for any purpose other than teaching on a secondary or
vocational school level.  Their use for even teaching has most likely
diminished to very little in say, the past 25 years as the general nature
of a science or physics curriculum has changed. 

	In years past, the major vendors of such induction coils were the
Central Scientific Co (Cenco) and the William Welch Co.  As far as I know,
Cenco has been out of business for 20 or so years, and Welch survives
only in its vacuum pumps as the Sargent-Welch Co.  Both Cenco and Welch
catered heavily to the educational marketplace.

	The only surviving vendor of educational scientific apparatus from
the "old days" is Fisher Scientific.  I looked in a Fisher Educational
Materials catalog from the early 1980's (separate and distinct from the
regular Fisher catalog), and found an induction coil of the type that you
mention.  It's price was $ 210.00.  Since we only order from the regular
Fisher catalog, I don't have a more current educational catalog from which
to quote a price.

> Where could you purchase antique spark coils from and for how much?

	There are a few dealers who specialize in antique scientific
apparatus.  One who comes to mind is Crystal Payton of Sedalia, Missouri.
I don't know what the going price is for such an induction coil, but
it is probably not cheap.

	Personally, I have a Cenco coil which easily makes 4 inch sparks.
It is all polished wood, and dates to around 1940.  I have not powered it
up in several years, though, for fear of damaging the coils, the insulation
on which is now obviously rather old.

Larry Lippman @ Recognition Research Corp.  "Have you hugged your cat today?"
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