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*To*: tesla-at-pupman-dot-com*Subject*: RE: Tesla Coil Bl.. Streamer Load reflects Resistance & LC + Robotics WIN*From*: "Tesla list" <tesla-at-pupman-dot-com>*Date*: Tue, 10 Apr 2001 21:45:59 -0600*Resent-Date*: Tue, 10 Apr 2001 22:11:58 -0600*Resent-From*: tesla-at-pupman-dot-com*Resent-Message-ID*: <8JaKOC.A.h-B.Lm906-at-poodle>*Resent-Sender*: tesla-request-at-pupman-dot-com

Original poster: "Hall, Dale by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Dale.Hall-at-trw-dot-com> Hi all, I would remind the list of the important relationship between Parallel Loads (resistive for simplicity) on the secondary such as corona, streamers, & power arcs that may be expressed as secondary series equivalent resistance (& coupled back to Pri): RequivSeries = XL^2/RparallelLoad Cap, C Xc = cap's reactance (corona & streamers load takes place within the plates of a virtual Secondary Capacitance - the topload to everything else) or Inductor XL = inductors reactance Rp = resistance in Parallel with Cap (dielectric leakage, Requiv of Spark !) Rs = ESR: resistance equivalent to Rp (substitute for ckt modeling) Rs = Xc^2/Rp = 1/(Rp*(2PiFC)^2) The nature of corona and streamers is chaotic the equivalent series resistance is as well. Regards, Dale !-at-#%-at-#%&$%(*&^*&)^%$^%#-at-$% NEWSFLASH !! my TRW Team 294, Redondo Beach, California, just won the FIRST Nationals Robotics Championship held at Epcot, April 5-7, (For Inspiration & Recognition of Science & Technology) (>550 robots registered, 335 showed at nationals) breaking scoring records 4 times relative to previous 13 regional contests held across US in March in alliance with teams Team 71 - Beatty Machine and Manufacturing & School City of Hammond Team 294 - TRW, Computer Assoc A & Mira Costa & Redondo Union HS Beach Cities Robotics Team 125 - Northeastern University/ Textron Systems & Boston Latin School & Brookline HS & Milton Academy Team 365 - E.I. du Pont de Nemours & Company, Inc./ DuPont Engineering Explorer Post Team 279 - Dana Corporation & Toledo Technology Academy & Rogers HS see www.usfirst-dot-org for more info. :-)) Thanks Terry :-)) -----Original Message----- From: Tesla list [mailto:tesla-at-pupman-dot-com] Sent: Tuesday, April 10, 2001 6:00 PM To: tesla-at-pupman-dot-com Subject: RE: Tesla Coil Blunders Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-uswest-dot-net>" <couturejh-at-worldnet.att-dot-net> Malcolm - When I mentioned coilers I was thinking of all coilers including myself and I did not mean to insinuate incompetence. I believe that coilers may be ignoring the very important resonant frequency equation and the R term that is vital in describing how a Tesla coil operates. It may be a big mistake not to explore the R in this equation during TC operation. This can be done by determining the operating resonant frequency and comparing it with the Wheeler/Medhurst/ resonant frequency. In the past any change in resonant frequency may have gone unnoticed because the tests were not accurate enough. It is interesting that this resonant frequency reduction due to the size of the R is not mentioned in electrical or radio publications except the Tesla Coil Construction Guide. One reason may be that with radio transmitters the R in the output (radiation) is always low enough to have only a negliable effect on the resonant frequency. However, this is not true of Tesla coils which produce much higher voltages and have high resistance and current outputs. I think you can forget the R in the Q factor equation because this resonant frequency R is not the same. This R has to do with the secondary output and cannot be measured during TC operation. However, it can be easily calculated when the reduced resonant frequency is known. This R would also be handy in finding the secondary voltage by Ohm's Law because the current in the secondary can be measured during TC operation. It will require many unique tests by coilers in the future to find the R's of various coils and to develop a graph for TC design. John Couture --------------------------- -----Original Message----- From: Tesla list [mailto:tesla-at-pupman-dot-com] Sent: Sunday, April 08, 2001 2:54 PM To: tesla-at-pupman-dot-com Subject: RE: Tesla Coil Blunders Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-uswest-dot-net>" <m.j.watts-at-massey.ac.nz> John, .... Check your maths - there is an error in it. On 6 Apr 01, at 12:19, 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 - > > It appears the resonant frequency equation is beginning to reveal some > of it's secrets. Most coilers take this equation for granted not > realizing that it has some interesting properties for the Tesla coil. > One of those properties is that if the R is large enough you will end > up with a square root of a negative number. As I say in the TCC Guide > that shows this equation when the R is large enough there will be no > resonant frequency. This would probably never occur with TC operation, > however, some R value is always present in the TC system when > operating. The R is normally small enough and can be ignored with > signal generator low power tests. But how about the R when the TC is > operational? Are coilers blundering in this matter. > > With the operational secondary circuit the R includes all losses plus > the load. The load during operation includes streamers, corona, > radiation, etc. It is obvious that the load can present a large > variety of conditions during operation. Researching these conditions > could help obtain better output from the TC system. One exception is > when sparks to ground occur which is a direct shorting of the > secondary circuit to ground. This means that tests would be made only > with (small streamers?) and not strikes to ground. > > For the above to have any significance the following question must be > answered. Does the resonant frequency reduce when the TC is > operational compared to the low power signal generator measurements? > If it does how does it affect the R of the resonant frquency equation? Chicken or egg? Which? Are you saying a drop in frequency affects R or that R effects a drop in frequency? Be absolutely clear what you are saying. R does not increase if there is no output discharge of any sort. In fact, it is liable to decrease in the ground path. The loaded Q of 10 I gave incorporates attached streamer loading and is a typical figure measured by myself and others. > These are difficult tests to make with resonable precision (+/- 1%?) > and maybe standard test methods should be set up so the test results > are more coordinated. In the past the few tests of this type that have > been made have given conflicting results. > > John Couture All I can say is that appeals to mysticism and disregard for that which you do not understand has no place in scientific enquiry. Sorry to be so pointed but you threw the gaulntlet down. Malcolm

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