2012/6/15 andy pugh <bodge...@gmail.com>: > On 15 June 2012 06:58, Viesturs Lācis <viesturs.la...@gmail.com> wrote: > >> Unfortunately it requires relatively larger power supply with higher >> current output. > > This is a problem with motors like the Keling ones, with a 48V rated voltage. > It is far simpler to make a 300V PSU than a 48V one. Simply rectifying > mains voltage into a big capacitor makes a PSU that the 8i20 is happy > with.
Yes, I even have servos with 330V rated voltage, but they are too small current-wise for 8i20. > Those Keling motors have a 500V / 1 min rating. I don't know if that > meas that they can run indefinitley on a 300V PWM (with a 48V > "average" or not). In the US I suppose a rectified-mains PSU would be > around 150V which sounds more reasonable. Hmm, this sounds tempting, I can get 1 kW transformer not very expensive with something like 42 VAC output, rectifying that will give something close to 60 VDC... What are the risks, when brushless servos are ran on overvoltage supply? Will they just be warming, which I think is tolerable or is it a nice way to damage them? > 3x rated voltage, and it is conventional > to run steppers at that sort of overvoltage Those Nema 23 steppers that I have used are rated at 5,46 VDC for with windings connected in series for bipolar drive, I am running them with 28 VDC in one machine and 48 VDC in welding robot, so that is getting close to 10x overvoltage. But what about brushless servos? Has anyone tried that and gained some experience to share? -- Viesturs If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
