*To*: Tesla Coil Mailing List <tesla@xxxxxxxxxx>*Subject*: Re: [TCML] CW Tesla Coil calculations?*From*: William Howard <snakeprior@xxxxxxxxx>*Date*: Thu, 14 Aug 2014 18:01:54 +0800*Delivered-to*: teslaarchive@xxxxxxxxxx*Delivered-to*: tesla@xxxxxxxxxx*Dkim-signature*: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=dy9xxY00/1J7TwS8bD2fyGrtyIjx0Lw8y52K5Kxz7kQ=; b=nkLkmlIFGE1OW2wRUVk6VJAn8EcSBXKtiH4LDctykUKSwMffCij/nhk2JGRCUlbeqv zYtl1hH2NIUFWhzLylAF1xc29QUg5WKY84eI64lfOAH8lcC0YRRNiLOh+pbykKUlrVMy sKhRYXjko4ilRoaNzKUH3FxP4+ZtuF4Bihb8CcHsm04jxUc+OCYeUDyhhE39fmyeyiea etP+0sZvBw+7b5YUHVTOI8VNGkdmGh/0jdJzVc0PGzxMo880XnhTv2fItRjTGn1sizpp Wpolr/bjdviw2W2krjOGIdwGRaniFp+xVa3FbH8acdnQqLP80d1P9cxh+WjZecNJH+/A tTXA==*In-reply-to*: <CAD=yrfmFjp60fVYHcAz74RTGkFgWBME5EnoHekc3jQQoXg9==Q@mail.gmail.com>*List-archive*: <http://www.pupman.com/pipermail/tesla/>*List-help*: <mailto:tesla-request@pupman.com?subject=help>*List-id*: Tesla Coil Mailing List <tesla.pupman.com>*List-post*: <mailto:tesla@pupman.com>*List-subscribe*: <http://www.pupman.com/mailman/listinfo/tesla>, <mailto:tesla-request@pupman.com?subject=subscribe>*List-unsubscribe*: <http://www.pupman.com/mailman/options/tesla>, <mailto:tesla-request@pupman.com?subject=unsubscribe>*References*: <CAPaHzuhRmNT3tz7piY6h18fF055To6QWpOOy20Vjf_DxAEv65w@mail.gmail.com> <CAD=yrfmFjp60fVYHcAz74RTGkFgWBME5EnoHekc3jQQoXg9==Q@mail.gmail.com>*Reply-to*: Tesla Coil Mailing List <tesla@xxxxxxxxxx>*Sender*: "Tesla" <tesla-bounces@xxxxxxxxxx>

Dear Steve, This explains perfectly the problems I have been having. It also explains why using a tickler coil that is a few extra turns at the base of the secondary leads to easier tuning (for myself). I had problems with the tickler coil resonating with the primary and a lot of head ache with positioning it. One further question: at higher frequencies the tank capacitance is smaller does this impact on the amount of 1/2 rf cycles needed to transfer energy? I read somewhere that the longer the energy takes to transfer (ring up) the longer the spark length. I started out with VTTC building by reading your FAQ. It was and is a very helpful and informative reference and I thank you for taking the time to write it! I will give that software a go and adapt an equivalent circuit for the magnifier as the model. I found this circuit in an article covering triple resonance and it covers mutual capacitance and inductance. Cheers! -Wil On 14/08/2014 7:11 AM, "Steve Ward" <steve.ward@xxxxxxxxx> wrote: > Wil, > > Java TC is fine and calculating the resonant frequencies of coils, however > it does not tell you what frequency that the coupled coils will resonate at > together. Because there is a mutual inductance between the coils, the > operating frequency will be somewhat different than the resonant frequency > of either the primary or secondary. The field of the 2 coils can add, > resulting in a lower operating frequency than the resonant frequencies > (often referred to as the "lower pole" mode), or the fields can cancel and > the operating frequency will be higher than the Fres of either coil (upper > pole mode). The coupling coefficient determines the mutual inductance, and > consequently how far away the operating frequency will be from the > "resonant frequency". > > I suggest using a circuit simulator like LTspice (which is freeware), and > making a model from the Ls and Cs that javaTC reports. From here you can > run an AC sweep analysis and spot the possible operating frequencies, which > show up as peaks in the response (this is where the term "pole" comes from > as the frequency response has distinct peaks that resemble something like a > circus tent held up by a pole). > > Richie Burnett has a good write up about frequency splitting, which is the > same phenomena im trying to describe: > > http://www.richieburnett.co.uk/operatn2.html#splitting > > The only real distinction to be made about a CW coil is that you are not > exciting both pole frequencies (like a SGTC does, for example, and the > result is a beating waveform... the sum of 2 frequencies). CW coils will > "settle out" at one pole or the other, depending on tuning and how the > circuit operates. > > As to what frequency produces the longest sparks, thats a really tough > question. Higher frequency operation produces a hotter arc which can grow > longer for a given voltage, however its not free lunch since efficiency > often drops at higher frequency operation due to resistive loss, and losses > in the tube. Id probably go for lower frequency operation if larger sparks > were the target, mainly to get the efficiency up so that more power could > be processed before melting down. > > Steve > > > On Tue, Aug 5, 2014 at 11:56 PM, William Howard <snakeprior@xxxxxxxxx> > wrote: > > > Dear Group, > > I'm having a dreadful time tuning my VTTC. I have been using Java TC as a > > guide for primary turns and using multi taps. > > > > My question is: is Java TC calculator accurate for CW Tesla Coils or > would > > the frequencies be different? > > > > Further more what is the best frequency for spark length? I've noticed > the > > spark becomes shorter and more flame like above 1mhz until 6mhz it > becomes > > a flame. > > > > If I were to design the optimum system what resonant frequency of the > > secondary should I use to get the longest CW spark? > > > > Cheers! > > -Wil > > _______________________________________________ > > Tesla mailing list > > Tesla@xxxxxxxxxx > > http://www.pupman.com/mailman/listinfo/tesla > > > _______________________________________________ > Tesla mailing list > Tesla@xxxxxxxxxx > http://www.pupman.com/mailman/listinfo/tesla > _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla

**References**:**[TCML] CW Tesla Coil calculations?***From:*William Howard

**Re: [TCML] CW Tesla Coil calculations?***From:*Steve Ward

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