On 22 November 2010 16:16, Spiderdab <77...@tiscali.it> wrote: >> The stepper drive will limit the current to the set value, so >> steady-state the voltage across the motor will be exactly the same as >> it is now (about 2.5V). The advantage is that when the motor is >> spinning rapidly it can still supply the same current with a 50V >> back-emf. >> > didn't understand this part. have you got a name of a drive i could use?
A stepper drive should run at constant current. However a stepper motor (in fact any motor) can also be considered as a generator. To push the required current through the motor you need a supply voltage which is higher than the voltage that the motor generates at that speed. So, while the stepper motor might need 2.5 volts to push 2A through it when static, it takes 50, 70, maybe 100V to push the same current through it at high speed. This is a 70V drive: http://www.slidesandballscrews.com/2m880n-microstepping-driver-p-303.html?cPath=44_97 And for even more money, this one runs direct from mains voltage input: http://www.slidesandballscrews.com/2m2280n-high-voltage-stepper-driver-p-304.html?cPath=44_97 (And, while we are there, these drives designed to bolt direct to the back of the motors look interesting) http://www.slidesandballscrews.com/uim24008-miniature-stepper-driver-p-483.html?cPath=44_97 > i've seen that, and found it very interesting! a suggestion on where to > find such motors? eBay? Or, if somebody else is paying: http://www.inverterdrive.com/group/Servo-Motors-AC/default.aspx -- atp ------------------------------------------------------------------------------ Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 & L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today http://p.sf.net/sfu/msIE9-sfdev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
