Re: Tesla coil grounding and other questions

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

Original poster: "June Heidlebaugh" <rheidlebaugh-at-desertgate-dot-com> 

Joseph: Just reading your posting may I suggest your capacitor is of low
value. I used glass plate capacitors years passed. If you double the total
capacity you half the primary size.
        I  made my glass plate capacitors with salvage glass squares from the
window shop and aluminum " off set press plates" from the news paper , 3
glass plates 1 metal, stacked high enough to fire a TC coil. No meters and
no test equipment, trial and error.



----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, February 13, 2004 12:18 PM
Subject: Tesla coil grounding and other questions


 > Original poster: JOSEPH CACCIATORE <jocatch-at-us.ibm-dot-com>
 >
 >
 > Hello. I am trying to resurrect my old tesla coil I made in high-school 30
 > years ago with plans that came from the July 1964 Popular Electronics
 > magazine. I still have the secondary coil and 12kv, 30ma NST which I want
 > to use. The secondary was built pretty close to the article, 4.75"
 > diameter, 34.625" long using #26 (or was it #28) wire. The NST is center
 > tap to the case.
 >
 > First question is grounding. The 120 vac for the NST of course is not
 > grounded (only 2 leads to the outlet). The design I have shows the bottom
 > of the secondary connected to one side of the primary tesla coil in an
 > auto-transformer arrangement. That is how the original design worked and I
 > was able to get 2 or 3" sparks from it.
 >
 > But reading on the net I see some places which say ground the bottom of
the
 > secondary to the case of the NST only and some show the bottom going to
 > earth ground only. Which is correct? If I want to run it in a house or
 > display like at school, there won't be an earth ground to begin with.
 >
 > Also, if you have seen the PE issue, they had the spark gap in series with
 > the primary but all circuits I see on the net today shows the capacitor in
 > series. Is that better?
 >
 > For the capacitors, I am using thick window glass and aluminum foil, each
 > glass is about 18"x18". I am using 2 of them.
 >
 > Lastly, since I have about 75' of 15kv wire I want to make the primary
 > using the wire in a helical coil arrangement (I don't have copper tubing
 > nor anyway to bent it nor a mount for it). I assume I will need all the
 > wire since my basic calculations show I would need 52 turns for the
 > primary. Since 52 would require more wire than I got, could I go with a
 > harmonic and use 26 turns for the primary?
 >
 > Thanks for any input you guys may have. I got this beautiful secondary
coil
 > I made and NST and I really would like to make it work.
 >
 > JC
 >
 >