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Re: Scroungein' (fwd)

to: Chris, Ross

Resonance Research buys them 25 pcs at a time and will send individual
units.  They are the best and we have never had one fail in commercial
service for over 20 years.

Regards,

Dr.Resonance-at-next-wave-dot-net


-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Monday, April 19, 1999 3:52 AM
Subject: Re: Scroungein' (fwd)


>Original Poster: Ross <ross-o-at-mindspring-dot-com>
>
>>>Original Poster: "christopher boden" <chrisboden-at-hotmail-dot-com>
>>><snip>
>>>Project 1
>>>Design Goal: To produce 5' discharge from a 120VAC <20Amp input.
>
>Attainable!
>
>>>Secondary size: 25" X 4"
>>>Secondary winding: 26 AWG? (any ideas?)
>
>24 or 22 ga are also good choices.  Look for "Heavy build" or the
>thickest coating that you can get your hands on.
>
>>> Secondary form Schedule 40 PVC 4" pipe with glued on endcaps
>
>You are better off with the thin walled stuff like SDR.
>
>>>Winding method: Lathe....BIG lathe.
>>> Primary winding: 1/4" soft copper tubing
>>> Primary form: Flat helix?
>
>Flat helix or something with a small angle will be fine.  I wouldn't go
>over about 15 degrees or you may have to significantly raise the
>secondary to prevent flashover and other problems associated with high
>coupling.  I am fighting that battle right now...
>
>>>Primary size? Number of turns/spacing????? any ideas?
>
>Many people have good luck using spacing about the width to the tubing.
>I used 1/4" tube and 3/8" spacing with good results.  The 3/8" gives you
>a little more room to place your tap.  You need to do some math on the
>sizing issues.  You should get your hands on one of the Tesla Coil
>Calculation programs that are floating around out there and numerically
>test various configurations.  I like the excel spreadsheet by Sonderman
>/ Ruch.  I have it on my page at
>http://www.geocities-dot-com/CapeCanaveral/Cockpit/3377/tesla/index.html.
>
>>>Caps: Where can we get some? What size do we need? How long will they
>>>ast? We need rock-solid-reliability.
>
>The only way that you will get "rock-solid-reliability" is with
>commercially built caps such as Maxwell.  Be prepared to spend hundreds
>of dollars if you find them surplus and around $3000 if you contact
>Maxwell directly and have them do a special run.  Why not build rolled
>LDPE, salt water, or MMC?  Most coils in the size that you mention do
>well with between .01 and .05 uF.  Typically, coilers design the cap
>size to allow for resonant charging, but there has been some discussion
>lately that this may not be the optimal way.  A .027 uf should produce
>resonant charging for (2) 12/60s in parallel.
>Again, consult some equations or one of the TC calc programs for more
>insight into sizing various coil components.
>
>>>NST: 15KVAC -at- 30mA
>
>You have big aspirations if you want 60 inches of arc from this...  I am
>getting 50 inches out of (2) 12/60s in parallel.
>
>>>Variac: ? what size do I need 20A?
>
>A non-PFC 15/60 NST draws about 9 amps.  You will probably draw about
>half of that with your current NST.  Most variacs are good for 2X their
>rated value for short runs.  I have been running my (2) 12/60s off a 10
>amp variac for some time with no problems at all.  Bigger is better if
>you catch a good sale.
>
>>>Spark Gap:Static (no shrapnell) possibbly the Quick model
>
>I have great results with my RQ gap.
>
>>>Torus: ?? biggest possible?
>
>Depends on what you want.  If you want it to be pretty and have many
>streamers dancing around in the air, then you will want a smaller
>Toroid.  When you go for your distance records, you will want a larger
>toroid.  It isn't all that difficult to make the toroid so big that you
>will never get spontaneous breakout.  In order to get breakout, I have
>to put a sharp point on my 7" dryer duct torroid with a 29" inch OD.  My
>4" x 20" is much more exciting to watch.
>
>>> Anything else? What am I forgetting?
>
>The filter network to protect your NSTs is non trivial.  Several of us
>in the So Cal area are having good results with Terry's RC filter, but
>the resistors dissipate about 75W each with 120ma flowing through them.
>Needless to say, it doesn't take them long to get really HOT.
>Commercial EMI/RFI filters are a good idea to keep RF out of your variac
>and house wiring.
>
>Be careful.
>
><snip>
>>>Christopher A. Boden
>>> The Geek Group
>>>344 Ionia SW
>>>Grand Rapids MI
>>> 49503
>>>(616)-574-4065
>>>The Geek Shall Inherit the Earth!
>
>Making arcs in Huntington Beach, CA,
>Ross
>