sam sokolik wrote: > there are actually 4 coils. Each head has 2 shielded cables coming from > the head - each cable has 4 conductors + shield. At the controller - > the 2 coils on each cable are hooked together to form a center tapped > setup. (agian - if I have it right - they excite the 2 outside > connections of the 2 center tapped hookups - then the center taps get > summed together and shaped. this from trying to read the desciption on > the schematic I scanned - plus you can see the coil hookups) :) > I don't know, looking at the jpg of the schematic, it doesn't really look like the windings will work the way you want for the AD chip. It really doesn't look like there is an excitation winding and a pair of sense windings. With 114 Ohms per coil, the drive requirement can't be terribly high, so that may not be a problem. If the AD chip can be made to work, the resolution will be 4096 counts per period of the teeth on the long scale. That probably is OK, as I think these teeth are about 10 per inch. Ah, yes, I see it IS a GE Accupin scale, I had already guessed it might be from your description. The way one of these schemes worked is they drove sine-wave signals in quadrature to the two sin/cos windings, and then looked at the time of the zero crossing on the other winding. That told the position of the windings relative to each other. This one almost sounds like it works the same way, but the description says square wave. So, maybe they are using some analog scheme to also sense the voltage of the output as well as the phase.
Anyway, it looks like this may be fairly hard to make work. Jon ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
