On Tue, 2013-01-08 at 11:53 -0800, Peter C. Wallace wrote: > On Tue, 8 Jan 2013, Viesturs L?cis wrote: > > > Date: Tue, 8 Jan 2013 21:28:48 +0200 > > From: "[UTF-8] Viesturs L?cis" <viesturs.la...@gmail.com> > > Reply-To: "Enhanced Machine Controller (EMC)" > > <emc-users@lists.sourceforge.net> > > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > > Subject: Re: [Emc-users] LinuxCNC craziness > > > > 2013/1/8 Peter C. Wallace <p...@mesanet.com>: > >> On Tue, 8 Jan 2013, Viesturs L?cis wrote: > >>> > >>> Should I get a ring for each lead or should I use all 4 leads of each > >>> motor on one ferrite ring? > >>> And is it enough to simply run them through the center or should I > >>> wrap it around at least once (put through center, wrap around and once > >>> again through center in the same direction as first time)? > >> > >> You should put the U/V/W wires (not the ground) from one channel all > >> through > >> one ring (this is what called a common mode choke it has 0 net current > >> flow so > >> does not saturate from the motor current) > >> > >> The point of this is to add some series impedance to the (very stiff) 28V > >> square wave driving into the cable and motor stator winding/frame > >> capacitance. This limits the amplitude of the current spikes created by > >> driving into this capacitance. > > > > Thanks for the explanation! So is it enough just to put it through > > once or should I wrap at least once around the ferrite? > > This depends a lot on the ferrite characteristics. You will probably have to > experiment. > > > > > Since previous replies have got me into considering of replacement of > > motor wires to something with a shield, I have a question - what would > > be minimum recommended wire lead "thickness" (I mean the area in mm^2) > > for 7i39 drive? > > > the 7I39 can supply 10A continous max through one phase so 14 Ga is about > right but 12 Ga would be better (~2 to 3.3 MM^2) > > > > > -- > > Viesturs
Hi, I must say that the conversations between Viesturs and Peter provide good information for the rest of us also. Viesturs ... you make a good guinea pig, no offense intended. This allows us to learn without going thru all the pain. ;-) I don't suppose there is any way to reconfigure so the cable runs are shorter. Hang in there and good luck. Dave > > > > If you can't fix it, you don't own it. > > http://www.ifixit.com/Manifesto > > > > ------------------------------------------------------------------------------ > > Master SQL Server Development, Administration, T-SQL, SSAS, SSIS, SSRS > > and more. Get SQL Server skills now (including 2012) with LearnDevNow - > > 200+ hours of step-by-step video tutorials by Microsoft MVPs and experts. > > SALE $99.99 this month only - learn more at: > > http://p.sf.net/sfu/learnmore_122512 > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > Peter Wallace > Mesa Electronics > > (\__/) > (='.'=) This is Bunny. Copy and paste bunny into your > (")_(") signature to help him gain world domination. > > > ------------------------------------------------------------------------------ > Master SQL Server Development, Administration, T-SQL, SSAS, SSIS, SSRS > and more. Get SQL Server skills now (including 2012) with LearnDevNow - > 200+ hours of step-by-step video tutorials by Microsoft MVPs and experts. > SALE $99.99 this month only - learn more at: > http://p.sf.net/sfu/learnmore_122512 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Master SQL Server Development, Administration, T-SQL, SSAS, SSIS, SSRS and more. Get SQL Server skills now (including 2012) with LearnDevNow - 200+ hours of step-by-step video tutorials by Microsoft MVPs and experts. SALE $99.99 this month only - learn more at: http://p.sf.net/sfu/learnmore_122512 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
