From: "Barton B. Anderson"
Date: Sun, 20 Oct 2002 16:17:50 -0700
Subject: Re: [TSSP] F A N T C: - It's NEW! - and needs some TSSP input
Hi Greg, Paul, Greg Leyh wrote: > The r2=r1+ypilson rule seems reasonable. I'm not sure that > anything really needs to be done, other than perhaps adding > it as a footnote in the help window for 'Define Primary'? True, a footnote can be used, but I should be able to allow for this by checking the number of turns. If 1, then allow r1=r2 as long as their not 0. It's on my to-do list. At the moment, I'm still working on NS7 issues. > I'm trying out some impractical coil dimensions now, and I > was wondering what the limits on physical dimensions should > be for this algorithm, if any, to maintain accuracy. Inductance here is Ldc and other influences are not rolled up into the compuation as it is with Ces, etc.. Paul, I did notice an issue with all inductances while probing through Gregs loop. If I run one analysis, I'll get the same value as Greg. However, should I run a second, third, etc.. analysis, L increases consecutively. This is performing a var coil = G.install_coil (....) and for each run, a new coil is being installed and inductances increase accordingly. G.reset() sets the rings to 0, however, I need some method to either check for previously installed components or simply a method to clear out any installed objects if they exist. Similar to a G.reset(), maybe G.remove()?. Also, if I perform a G.remove(coil) and the coil doesn't exist, it will error out. However, if it could simply return false in that situation, it may prove advantageous in other areas. > Given the following inputs for the coil dimensions: > Inside = 240 > Outside = 240.1 > Bottom = 0 > Top = 0 > Turns = 1 > FANTC yields 66.44uH for the primary calculator, and > 0.07mH for the secondary calculator. > (BTW, the algorithm appears to not yield any results if > the primary and secondary have identical dimensions; a > silly case though, I'll admit.) Interesting. I couldn't reproduce this. I entered the same dimensions and both secondary and primary ran ok (however, both increased L on consecutive runs as mentioned above). > To resolve the wide range in calculated results, I set out > a 20ft diameter circle of RG-174 coax cable in the parking > lot and measured the inductance of the outer jacket (~0.1" dia). > The inductance meter gave 32uH, measured at 1kHz. > > Perhaps the measurement is skewed by physical factors, such > as random bits of metal under the asphalt, although the test > was done over a recently laid patch of asphalt with no metal > remesh. Does this coil have proportions that incur high > calculation errors? I'll have to let Paul answer those. Take care, Bart
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.