I get confused because when i just load one of the files,i see a "dee" at the left of the screen, with a dinky "scribble" near the right of the inside. This time around,i fiddled around and was able to move that and enlarge the drawing,and saw what appears to be two separate coils with different centers. Obviously neither being in free space, nor concentric may tend to alter results.
"define", "block" are unknowns to me. If that "dee" was a block, i would have made it a large circle (assuming i could figure out how). Then make a coil in the exact center (ditto). Then run current thru it (say DC for starters) and look at over-all field as well as field in each wire of the coil (ditto). Am talking about doofus me unknowns.
no comment on your 3 values using 100 ohm series R showing a 'constant
10.8mH ??
This form of measurement VERIFIES that when the inductor is properly modeled [as 10.8mH], you get LTspice/PSpice to yield proper rsults. Of course there is a different answer when L is put into the schematic as
21.6mH. Perhaps, that L meter does not like a large value of resistance in series?
see below
that 'dee' is the WHOLE field of view, nothing outside that area.
First, there are two forms of analyses, axisymmetric and planar. Axi is ACCURATE in 3D !!! so I use it whenever possible. Those are the types I sent you. Planar extends off into space above and below the 'page' for infinite distance. You specify the 'depth' only to calculate the forces etc. Useful but must be careful when using.
Second, I ALWAYS use a circle wrapped around my region and then set that boundary to act like an infiniely far away boundary to not distort any fields.
To understand axisymmetric, you must envision a 2D drawing that can rotate about its center axis. Thus the drawing appears as the 'right' half of the whole thing only, a line alonng the r=0, going from +/-z range to just intercept the boundary, in this case a 180 degree curve. So over all the image when loaded "looks' like the 'dee' you see. There are two ways to enlarge and explore that image, the simplest is the set of four 'magnifier lense' icons along the left side, labeled +, -, circle, and something at the bottom. The something at the bottom activates the ability to use the cursor and draw a small box around any region with left click, hold, move cursor, release, and the area inside the box zooms into full view. That would enable you to quickly draw a box around that tiny squiggle and it would suddenly bloom up into full view. If you click on the icon just above this bottom one, the WHOLE view comes back into view. and you get to start over.
Now since you understand the significance of the drawing, you can see that inside the squiggle area, the bottom cross section circle is the main L1 with a small cross circle represent the added L@, loosely wrapped above the main coil. What you're viewing is a slice of the coil. So the main coil is a circular loop and the smaller coil is also a circular loop just above the main coil.
To activate the results and view, you must RUN the program. Two ways, one is select RUN from the menu, and the easiest is to simply click on the icon that looks like a gear with a crank on it. That activates the program to SAVE the *.fem file as is [so if you changed it, it is now in concrete] then form a mesh, then do all the calculations to solve the problem, then returns to your original view. To VIEW the results there are two ways, the simlest is to click on the icon next to the 'crank' icon, the one that looks like a pair of glasses. then the WHOLE field of view comes in and shows you filed lines, etc. You can click anywhere and a little table shows you all kinds of information. Or, in our case ou can click on the little icon that looks like an inductor symbol and it shows you L1 results in henries and ohms. To view L2 you must select that circuit in the same little windo. When finished must 'x' out that little table. To go back to your original sturctural view, 'x' the lower image X, not the main X. and femm will rmove he results and go back to original structural view you had. Else you accidentally closed the whole rogram and have to start over.
Once the program has RUN, it creates a *.ans file that you can click on directly to view, or pull back up while viewing the original program [click on 'glasses'icon] wihout having to RUN again. Just haveto remember, that if you changed the original, no effect until hit RUN again, so old view is old run info.
Did some digging; that would be a purely mechanical consideration. Adds a bit of capacitance to the working leads, less than a pF. Good for monitoring frequency with almost no additional load.
I can only wonder if we're talking at cross purposes. Crystal cases soldere d to the pcb are pretty common. Xtal cans with a 3rd pin welded to the top end of the case are not unusual. I've never kept notes on what items have t hem, so its hard to give an example, but I've seen plenty in consumer equip ment.
Envision using the crystal. One often used standard use has a leg going to a high impedance input and the other leg going to the built-in output of some string of phase shifting amplifiers inside the PIC, FPGA, uProc, or ??. that means one leg of the crystal is flying +/-voltage and the other leg, unknown voltage swings. Plus, most crystals are ground for some additional phase shifting capacitance intended to be added just to bring the 'center' of operation to spec, like 20pF, 40pF, or 50pF. Why not? since you have parasitics anyway why not add some more to 'adjust' the frequency into spec. Ok now with EMC being an issue, it is NOT prudent to have some leads sticking up off your board with high voltage high freuency swings on it. Nope, that's like putting a little antenna out there. So, the solution? third contact to the can, or clip the can to GND. Thus providing physical stability AND shielding some potentially damaging RF/EMI voltages from splattering out. But, keep in mind, the crystal IS microphonic, so sometimes you want that mounting to have compliance and not transfer modulating vibrations, or in some cases, actually damaging vibrations to the crystal.
Which is most important. Who cares? the contact to the can mitigates both problems - mounting stability and shielding RFI/EMI.
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