*To*: Tesla Coil Mailing List <tesla@xxxxxxxxxx>*Subject*: Re: [TCML] CW Tesla Coil calculations?*From*: Steve Ward <steve.ward@xxxxxxxxx>*Date*: Wed, 13 Aug 2014 16:05:53 -0500*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=u7t57M3aJNCTWxSH0CtFX1Ag9z/pADd3WrPjzZzz6AA=; b=lDM0D5uIqOMOVQPDXZWoX5BxnH2VFDI4GdtSH2GTuzZg4uoKx/6Kgn06w1AR24m0KO vmdtYdPQQP9amX883W76ZzELqAl0ZoBofWohgq7eVzh5jHMWl3aLkVHutsmzeccJ3WWS d7dvAAg2OznQlNiyfWdT3hAH7mcn2+P6QGf6fWTmLgJNPPnnv+epDUkcp8BWVUZGtFvL agi17wE2UXWUHybJ+PM8lpqPO2sKqbCxXNsRCcjqymuAxWBJoa6WCJyb8uQM2AxSDhUf op0+P7G1ykWC0gK1ch4sLbiMULDvRxhD5uVHSMtDOb8VRRDOZU5vD14ldfHQdrzFUxv3 XPvw==*In-reply-to*: <CAPaHzuhRmNT3tz7piY6h18fF055To6QWpOOy20Vjf_DxAEv65w@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>*Reply-to*: Tesla Coil Mailing List <tesla@xxxxxxxxxx>*Sender*: "Tesla" <tesla-bounces@xxxxxxxxxx>

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

**Follow-Ups**:**Re: [TCML] CW Tesla Coil calculations?***From:*William Howard

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