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Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!mhuxv!abnji!jeff
From: jeff@abnji.UUCP (jeff)
Newsgroups: net.analog
Subject: re: Jacob's Ladder
Message-ID: <671@abnji.UUCP>
Date: Tue, 4-Jun-85 12:11:30 EDT
Article-I.D.: abnji.671
Posted: Tue Jun  4 12:11:30 1985
Date-Received: Thu, 6-Jun-85 03:28:46 EDT
Lines: 28
Keywords: safety, spritzensparken, special effects

[spritzensparken!]

	I have made a Jacob's ladder using neon sign transformers and
tv rabbit-ears.  It made nice thick white arcs that zidded up the ladder.
7.5kv was nice, 15kv was better, making arcs >1 inch.

	I tried using an igniter cell and a step-up transformer
with a relay in series with itself to commutate the primary but the sparks
produced were scrawney - weak thin sparks.  I guess that a constant
current of a few milliamps is needed to really ionize the air and give a
spark with some plasma to it.  I guess that safety and impressive results
are mutually exclusive.

	I notice that the Jacob's Ladders in the movies are in glass tubes.
This is not only for safety but also confines the ionized air to
aide the sparking process, and eliminates the problem of drafts blowing
the spark out.  Plastic tubes won't provide any insulation.
It's glass or nothing.  Even the standoffs used for neon signs are glass,
so take care with that insulation!

	For safety, I stayed 3 feet away from the thing when in operation
and it was mounted on a wood base, held up by a wood chest on a wood floor.
The neighbors probably weren't too happy with the EMI interference.

					Jeff 'neon red' Skot
					at the barely illuminated ATT IS
					Somerset, NJ
					{ihnp4 | mcnc | cbosgb} abnji ! jeff