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. > > > 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! 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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! 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