>While experimenting back-emf, I switched off motors while acquiring/reading. >What do you mean by "switch full-on/full-off", isn't just turning off while >reading enough ?
Of course that's enough. I just wanted to point out that switching full-on would be another suitable option. But as you have to measure current, not voltage, you'll need a path for the current to flow, and some means to allow the current to generate a voltage. So you'll need some resistors. >Also, I didn't power the motors with PWM but rather controlling pre-existing >h-bridges, bypassing PWM signals from a RC tank control board itself. Would >this still be a problem and would require to filter PWM frequency ? Err, well, I don't quite understand... The point is, the current through your motor windings, induced by rotation is in ranges of some hertz, at most about a kilohertz. In the same range could be your PWM frequency. So you've got the problem to distinguish one from the other. If you push the PWM frequency up to, say, 50kHz, it should be easy to filter that out and feed the motor with something that resembles a controlled, unmodulated, stable voltage. That will, however, increase switching losses in the bridge. >And, just my curiosity, do you have any pictures about what you've seen on the >scope ? Not yet. I'll try to make some, perhaps in a few hours already. Greets, Kiste -- You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jallib?hl=en.
