Re: Do these numbers look right?

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

Original poster: Esondrmn-at-aol-dot-com 

In a message dated 2/16/04 4:17:54 PM Pacific Standard Time, 
tesla-at-pupman-dot-com writes:


>Hello again. I am well on my way to designing my first TC after giving up
>trying to restore my old PE magazine coil from 1964. I checked and there
>are a slew of programs and spreadsheets written to help design a TC.
>Unfortunately some give different results for the same input conditions.
>
>The program I found to be extremely helpful is an Excel spreadsheet called
>the Tesla Coil Designer 3.0 by Ed Sonderman and Corey Ruch. It is great
>because you can adjust the secondary/primary parameters and watch for when
>they come in sync.
>
>But never trusting any program fully (i.e., Tax Deluxe say I had an extra
>$1800 coming back on my tax return, it was wrong!), I was hoping someone
>could verify and look at these numbers to see if the coil really will
>perform before I spend all this time, effort and money.
>
>If anyone is willing, here are the specs I came up with:
>
>NST = 12,000v, 30ma, 60hz
>Secondary = #22 wire, 20" long, 4" diameter, 765 turns-at-97%
>Primary = flat spiral, I.D. = 6", 15 turns, .25" pipe, .25" spacing,
>width=7.25"
>Capacitor = .007uf
>Toroid = Dmin= 4", Dmaj= 24"
>
>The spreadsheet says secondary res F = 257kh, primary res F = 221khz.
>
>My concern is if I use any larger cap, I can't get the prim/sec parameters
>to match good enough. Also, I don't have any material for a toroid here
>that I can look at so I assume 4" almunin flex hose but I don't know if 24"
>is realistic. Lastly, the primary requires 53' of copper tubing. I am not
>sure where to buy such a long length. I have seen only 25' at Home Depot.
>
>Thanks.
>   JC


Joseph,

I would suggest using smaller wire on the secondary to get up to 1,200 
turns or so, maybe #26 or #28.  I would also go with a .01 ufd 
cap.  Splicing the primary tubing is relatively easy.  Find a smaller piece 
of tubing that just fits inside the size that you are using.  Cut a piece 
maybe .5" long, clean up both ends to be joined, insert the smaller tube 
.25" into one end, pre tin with solder, slide the ends together, heat and 
apply solder, wipe excess off while still hot with a dry rag (like you 
would for soldering copper water pipe).  This makes a nice clean joint that 
is very hard to see.

Ed Sonderman