On Sun, Jul 18, 2010 at 09:32:40AM -0500, Stuart Stevenson wrote: > If that generated tach signal was sufficient for the amps in the late 70's > would the current technology be able to at least match it?
I have several competing ideas in my head about this. I will list them in order from least daring to most daring. 1. You could add tachs 2. I have some servo dynamics amps that take A,B encoder inputs as velocity feedback. This makes me think there is a simple way to do frequency-to-voltage conversion to get a velocity signal from quadrature. I bet many on the list are experienced enough in analog design to easily do this. 3. You could get extra DACS (an extra 7i33 mesa card) and send Mesa's high quality encoder velocity signal directly out an extra DAC. 4. You could assume that all the amp does with these two velocity signals is act according to the difference, command minus feedback. You could generate this difference in HAL by subtracting the encoder velocity signal from the pid output, and feed that difference out a single DAC. On the amp, just null out the other input. Frankly I'd try these in reverse order and see what gives you a stable loop. ------------------------------------------------------------------------------ This SF.net email is sponsored by Sprint What will you do first with EVO, the first 4G phone? Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
