From: "Terrell W. Fritz"
Date: Fri, 01 Jun 2001 13:05:51 -0600
Subject: Re: [TSSP] Secondary in motion
Hi Paul, For the secondary I get 241.3kHz and the primary really is 219.7. I was getting all confused by the large difference and the coils interacting last night. The primary (secondary removed) frequency plot is: http://hot-streamer.com/temp/TerryCW/2001-6-1/Tek00000.gif http://hot-streamer.com/temp/TerryCW/2001-6-1/PrimaryOnly.jpg With both coils installed: http://hot-streamer.com/temp/TerryCW/2001-6-1/Tek00001.gif http://hot-streamer.com/temp/TerryCW/2001-6-1/PrimaryAndSecondary.jpg That gives a primary inductance of 18.945uH. I think the difference is due to the fact the primary wiring is rather long going to the primary coil. http://hot-streamer.com/temp/TerryCW/2001-6-1/Wires.jpg The actual coil is probably the right inductance but the added wiring probably adds the other 3uH. The old primary is disconnected and makes a tiny difference but I use the base still since it has all the nice connections on it. Hope this clears things up. Cheers, Terry At 11:17 AM 6/1/2001 +0100, you wrote: >Marco Denicolai wrote: > >> Terry (or Paul), would you mind sending me the values of >> Ces and Les of the coil we are talking about? > >For the secondary with primary in place but open circuit, I get > > f1 = 244.5 kHz, > Ces = 22.6 pF > Les = 18.7 mH > >For the primary alone, ie secondary removed altogether, I get > > Lp = 15.6 uH > Cp = 27.16 nF > f = 244.5 kHz > >The above Cp is a little different to Terry's actual 27.7 nF - I >fiddled my value slightly to set the primary Fres to match the >secondary. > >Now, when the system is put together, I get the main mode frequencies, > > f- = 209.0 kHz > f+ = 299.9 kHz > >Terry's measured primary values are, > > Lp = 15.575 uH > Cp = 27.7 nF > f = 242.31 kHz > >and for the secondary, > > f1 = 252.91 kHz > >so that the real coil appears to be slightly out of tune as well >as over-coupled, whereas the modeled version over-coupled but >the tuning is pretty close. > >I'm going to adjust the model's Ctop slightly to bring the model's >secondary f1 into line with the real coil, and similarly for the >primary free resonance. Then the model will be equally out of tune, >and I'll recompute the dual resonator response once more. > >Hopefully we'll get a better match with that rather complicated over- >coupled and out of tune waveform. The comparison at present is >quite good on the mode amplitudes, but the phase is all over the >place. > >More to follow on this later, > >Cheers, >-- >Paul Nicholson, >Manchester, UK. >--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.