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- From: sichase@csa2.lbl.gov (SCOTT I CHASE)
- Newsgroups: sci.physics
- Subject: Re: What are those things called...
- Date: 24 Jul 92 19:33:02 GMT
- Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
- Lines: 35
- Distribution: na
- Message-ID: <24862@dog.ee.lbl.gov>
- References: <1992Jul23.214214.8574@microplex.com> <1992Jul24.134854.9052@lut.ac.uk>
- Reply-To: sichase@csa2.lbl.gov
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-
- In article <1992Jul24.134854.9052@lut.ac.uk>, A.J.Robinson@lut.ac.uk writes...
- >In article <1992Jul23.214214.8574@microplex.com> hsk@microplex.com (Harjeet Kalsi) writes:
- >>
- >>I know I've seen them in physics labs (including mine when I was in school)
- >>but forgotten what this "box" with two antennas, that has a high
- >>voltage spark travelling between the antennas from bottom to top,
- >>is called.
- >>
- >
- >I think they're called Jacob's ladders, but I could be wrong.
-
- Correct. I don't know if they serve any useful function, but the easiest way
- to make one is to take a pair of hack-saw blades and attach them to a HV
- AC source (I think I used a 5 kV source when I built one years ago) like a
- pair of TV rabbit ears, teeth facing teeth. A spark channel forms across a
- couple of the lowest teeth of the blades and heats the air in and around the
- channel, which causes it to rise up the blades until it runs off the upper tips
- of the blades or some kind of plasma instability disrupts the channel. At that
- point a new channel forms near the bottom of the blades where they are closest
- together.
-
- It produces a heck of a lot of ozone - not too good for your health. The
- blades get very hot - be careful. And you should probably make sure that
- you aren't going to blow up your supply if it shorts metal-to-metal. This
- is not a trick to try with any semiconducting electronics around which can
- fry.
-
- -Scott
-
- --------------------
- Scott I. Chase "The question seems to be of such a character
- SICHASE@CSA2.LBL.GOV that if I should come to life after my death
- and some mathematician were to tell me that it
- had been definitely settled, I think I would
- immediately drop dead again." - Vandiver
-