[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

*To*: tesla-at-pupman-dot-com*Subject*: RE: Tesla Coil Blunders*From*: "Tesla list" <tesla-at-pupman-dot-com>*Date*: Tue, 03 Apr 2001 13:20:14 -0600*Resent-Date*: Tue, 3 Apr 2001 13:37:23 -0600*Resent-From*: tesla-at-pupman-dot-com*Resent-Message-ID*: <9hkqK.A.CgH.uZiy6-at-poodle>*Resent-Sender*: tesla-request-at-pupman-dot-com

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-uswest-dot-net>" <m.j.watts-at-massey.ac.nz> Hi John, On 2 Apr 01, at 21:26, Tesla list wrote: > Original poster: "John H. Couture by way of Terry Fritz > <twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net> > > > Malcolm - > > Sorry - the two R's are shown in the following equations: > > Q = Xl/Rq Rq = Xl/Q > F = .159 sqrt(1/LC - (Rf/2L)^2) > > Rf = 2L sqrt(1/LC - (6.283F)^2) I think I detect an error in this last equation? Plug some typical figures in and try it. I did and ended up having to square root a negative number. > The Rq in the Q factor equation is the one to which you are referring. > The other Rf is the one in the Resonant Frequency equation and is a > different resistance. This resistance affects the resonant frequency > of the RLC circuit. Actually, both will because they are one and the same and are defined as the equivalent series resistance of the circuit. Let's assume a secondary with an unloaded Q of 200 and an inductance of 20mH and resonates at 200kHz. The first equation shows that ESR (Rq in your nomenclature)= 125.7 Ohms roughly. To resonate at this frequency, the equivalent capacitance (ignoring that loss for the moment) will be about 31.7pF. I now plug that resistance, inductance and capacitance into your second equation to find F. The change in frequency is absolutely trifling. If you don't believe me, do it. Now let's change to a loaded Q of 10. The first equation shows that ESR has risen to 2.5kOhms approx. Plugging this new figure for R into equation 2 shows the frequency now to have dropped less than half a percent, not exactly a convincing argument that R is responsible for a massive drop in frequency. > The meager TC operating test data (scope/antenna probe) I have been > able to collect from coilers indicates this Rf may be involved in > reducing the resonant frequency compared to the low voltage, low > current Wheeler/Medhurst/Freq meter test. If anything is dropping the frequency significantly it has to be streamer capacitance. > This resonant frequency reduction has resulted in coilers and TC > programers having to make an adjustment in the calculation of the > resonant frequency compared to the operating test. Apparently you > haven't noticed this reduction. My work coil shows no significant change in resonant frequency according to waveforms I've captured on the storage scope as compared with low power sig gen measurements. Regards, malcolm

- Prev by Date:
**Re: rectifying nst's** - Next by Date:
**Re: Need Ozone** - Prev by thread:
**Re: Tesla coil blunders** - Next by thread:
**Re: Tesla Coil Blunders** - Index(es):