On Sunday 28 February 2010, Steve Blackmore wrote: >On Sun, 28 Feb 2010 16:23:48 -0500, you wrote: >>I have 2 myself, abide by the rules and my machine can move 25 ipm with a >>27.5 volt supply. >> >>They are I believe the same allegro chip used on the xylotex boards, but >>xylotex puts heat sinks on them and recommends plenty of air flow for full >>output. And they Just Work(TM). > >Yea - just being the operative word :) > >The Allegro chip looks good at a glance, it's quick with 1us pulse times >but exceed around 32V at your peril. They have a nasty (and regular) >habit of going pop. With the right steppers you can get reasonably good >performance, but they need to be low impedance to get the best at such >low voltages. > >Steve Blackmore
I can't argue that Steve, having blown one. And that is the reason the output filter cap in my linear motor power supply is 75,000 uf. Yessiree Bob, gobble up them overvoltage spikes. ;-) And because of the limited out cap size in switcher power supplies, they are bound to be trouble. The simpler the better, but build it out of bulletproof stuff, pure analog. >-- > >--------------------------------------------------------------------------- >--- Download Intel® Parallel Studio Eval >Try the new software tools for yourself. Speed compiling, find bugs >proactively, and fine-tune applications for parallel performance. >See why Intel Parallel Studio got high marks during beta. >http://p.sf.net/sfu/intel-sw-dev >_______________________________________________ >Emc-users mailing list >Emc-users@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/emc-users > -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Air is water with holes in it. ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
