Hi Seb, >Do you think it can be "visible" for any DC motors ? The most dirty motors may >give the better results ? (lots of friction, maybe ?) I don't think the friction or anything does have a big influence. But yes, I think all commutator motors will give similar current curves. (It may differ for compensated motors, but you won't find compensated motors with less than several hundred watts ;-) )
>And, just my curiosity, do you have any pictures about what you've seen on the >scope ? Yes, now I have :-) Please don't laugh about my cheap taiwanese scope, I'll get a decent one as soon as I can afford it. And, yes, I could have connected it to a computer, but I had no windows machine within USB range... So there are some clumsy photographs. The motor is a nichibo MD38-14280-R with a 1:180 gear. The motor runs free, just the friction of the gear as mechanical load. The shunt is 2.2 Ohms. Power is constant voltage from a laboratory power supply. So here are the pictures: http://johannes.eventify.de/kiste-temp/motor/ No. 1 and 2: 7.6V, about 70 rotations per second No. 3: 3V, about 27 rps No. 4: 12V, about 108 rps No. 5: 1.0V, about 5 rps The rps are really more guessed than measured, by counting the rotations at the gear exit for one minute. But it is accurate enough to see that there have to be six pulses per rotation. The motor has three magnetic poles. 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.
