A small value capacitor decrease the problem so I guess the commutation spikes are the problem but driving a capacitive load is not good.
Nicklas Karlsson On Thu, 27 Nov 2014 08:54:59 -0600 John Figie <zephyr9...@gmail.com> wrote: > Many commercially available PWM drives require using shielded cable for the > motor. Also shielded Ethernet cable is used in many industrial > applications, but for the shielded Ethernet cable to work you must also > have RJ-45 connectors that have a metal shell with tabs to touch the shield > on the cable connector. > > John Figie > > On Wed, Nov 26, 2014 at 4:10 PM, Karlsson & Wang < > nicklas.karls...@karlssonwang.se> wrote: > > > 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! 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! 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