I would place the bead closer to the driver but I may be wrong. I assume fast voltage transistion is generated by the transistor so it would be better to limit the voltage derivative or in this case it will be a high frequency impedance in form of an inductor with a few turns with some space in between. I expect the tightly linded motor windings to have some parasitic impedance which I want to work around but I may be wrong.
On Wed, 26 Nov 2014 23:17:48 +0200 Marius Liebenberg <mar...@mastercut.co.za> wrote: > > On 2014-11-26 22:12, Peter C. Wallace wrote: > > On Wed, 26 Nov 2014, Karlsson & Wang wrote: > > > >> Date: Wed, 26 Nov 2014 20:53:56 +0100 > >> From: Karlsson & Wang <nicklas.karls...@karlssonwang.se> > >> 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] EMC communication problem then motor start > >> > >> The switching is very fast because gate transistor is 10 ohm so I will > >> increase as an intermediate solution. The problem is however still > >> interesting because it is so common. > >> > >> Nicklas Karlsson > >> > > One option that helps a lot on PWM drives is a common mode choke on the PWM > > outputs (a large ferrite bead on the 2 (DC) or 3 (AC) motor wires). One > > major > > problem with PWM outputs without slew rate limiting driving motor windings > > is > > the nearly unlimited current spike that happens at switching time because > > of the very fast slew rate PWM signal driving into wiring/ motor winding to > > ground capacitance. > > > Would you place the bead closer to the drive or closer to the motor? > > > > > > >> > >> On Wed, 26 Nov 2014 19:34:44 +0000 > >> David Armstrong <cncbas...@gmail.com> wrote: > >> > >>> i normaly make sure that all low voltage wiring is sheilded and watch for > >>> ground loops and vfd inputs are via filters and Balance transformers , > >>> ethernet coms are usually problem free so long as you use good cables and > >>> not the cheap Aluminium wire ones as they are using balanced paired cores > >>> , in 2 real major projects i ended up passing the low volt cables inside > >>> sheilding cut from ur67 coax > >>> > >>> > >>> > >>> On 26 November 2014 at 18:40, Karlsson & Wang < > >>> nicklas.karls...@karlssonwang.se> wrote: > >>> > >>>> I have tried with USB isolator made with Icoupler devices from analog > >>>> devices on other products without luck. I am using ethernet which I think > >>>> have a isolation transformer. I do not think there are any tolerances for > >>>> missed packets right now. For serial communication I have tried opto > >>>> couplers without with some improvement. I have also tried isolation > >>>> devices > >>>> from I think Texas instruments made from differential drive over two > >>>> capacitors and they are great but I do not think I could use them for > >>>> 100Mbit ethernet. > >>>> > >>>> I will increase tolerance for missed packets to be able to measure > >>>> percentage of lost packets, it is not perfect but better than nothing. I > >>>> will also add a common mode inductor and maybe a shielded cable. > >>>> > >>>> I have encountered the problem on several products so it is not isolated > >>>> to just this one I built myself. > >>>> > >>>> > >>>> Nicklas Karlsson > >>>> > >>>> > >>>> > >>>> > >>>> On Wed, 26 Nov 2014 19:28:25 +0200 > >>>> Marius Liebenberg <mar...@mastercut.co.za> wrote: > >>>> > >>>>> I have had many problems with USB communications with motors and plasma. > >>>>> You can overcome these by putting an electrically isolated barrier in > >>>>> the usb line. There are some chips from Linear (LTM2448) that will do > >>>>> just that. The equipment on either end cannot be connected to the same > >>>>> ground or supply if you go this route. > >>>>> > >>>>> On 2014-11-26 19:07, Karlsson & Wang wrote: > >>>>>> PWM is great for efficient motor but unfortunately it is also very > >>>> good at disturbing digital communication. Do anybody had any problems > >>>> with > >>>> the communication errors then motor start? > >>>>>> Nicklas Karlsson > >>>>>> > >>>>>> > >>>> ------------------------------------------------------------------------------ > >>>>>> Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server > >>>>>> from Actuate! Instantly Supercharge Your Business Reports and > >>>> Dashboards > >>>>>> with Interactivity, Sharing, Native Excel Exports, App Integration & > >>>> more > >>>>>> Get technology previously reserved for billion-dollar corporations, > >>>> FREE > >>>> http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk > >>>>>> _______________________________________________ > >>>>>> Emc-users mailing list > >>>>>> Emc-users@lists.sourceforge.net > >>>>>> https://lists.sourceforge.net/lists/listinfo/emc-users > >>>>>> > >>>>> -- > >>>>> > >>>>> Regards /Groete > >>>>> > >>>>> Marius D. Liebenberg > >>>>> +27 82 698 3251 > >>>>> +27 12 743 6064 > >>>>> QQ 1767394877 > >>>>> > >>>>> > >>>>> > >>>> ------------------------------------------------------------------------------ > >>>>> Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server > >>>>> from Actuate! Instantly Supercharge Your Business Reports and Dashboards > >>>>> with Interactivity, Sharing, Native Excel Exports, App Integration & > >>>>> more > >>>>> Get technology previously reserved for billion-dollar corporations, FREE > >>>>> > >>>> http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk > >>>>> _______________________________________________ > >>>>> Emc-users mailing list > >>>>> Emc-users@lists.sourceforge.net > >>>>> https://lists.sourceforge.net/lists/listinfo/emc-users > >>>> > >>>> ------------------------------------------------------------------------------ > >>>> Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server > >>>> from Actuate! Instantly Supercharge Your Business Reports and Dashboards > >>>> with Interactivity, Sharing, Native Excel Exports, App Integration & more > >>>> Get technology previously reserved for billion-dollar corporations, FREE > >>>> > >>>> http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk > >>>> _______________________________________________ > >>>> Emc-users mailing list > >>>> Emc-users@lists.sourceforge.net > >>>> https://lists.sourceforge.net/lists/listinfo/emc-users > >>>> > >>> ------------------------------------------------------------------------------ > >>> Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server > >>> from Actuate! Instantly Supercharge Your Business Reports and Dashboards > >>> with Interactivity, Sharing, Native Excel Exports, App Integration & more > >>> Get technology previously reserved for billion-dollar corporations, FREE > >>> http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk > >>> _______________________________________________ > >>> Emc-users mailing list > >>> Emc-users@lists.sourceforge.net > >>> https://lists.sourceforge.net/lists/listinfo/emc-users > >> ------------------------------------------------------------------------------ > >> Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server > >> from Actuate! Instantly Supercharge Your Business Reports and Dashboards > >> with Interactivity, Sharing, Native Excel Exports, App Integration & more > >> Get technology previously reserved for billion-dollar corporations, FREE > >> http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk > >> _______________________________________________ > >> 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. > > > > > > ------------------------------------------------------------------------------ > > Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server > > from Actuate! Instantly Supercharge Your Business Reports and Dashboards > > with Interactivity, Sharing, Native Excel Exports, App Integration & more > > Get technology previously reserved for billion-dollar corporations, FREE > > http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > -- > > Regards /Groete > > Marius D. Liebenberg > +27 82 698 3251 > +27 12 743 6064 > QQ 1767394877 > > > ------------------------------------------------------------------------------ > Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server > from Actuate! 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