Well Indeed it was a scope problem measuring the IGBT drives, since today everything went alright by that side. The problem starts now when I plug the transistor gates. So as I talked whith Gene, I'm going to connect the drives directly to the gates using shielded wire.
2013/2/11 Gene Heskett <ghesk...@wdtv.com> > On Monday 11 February 2013 12:41:34 Mark Wendt did opine: > > > On Sun, Feb 10, 2013 at 6:59 PM, Gene Heskett <ghesk...@wdtv.com> wrote: > > > 1 microsecond can be an eternity to an IGBT. As for your spikes, make > > > sure that the scope is /not/ grounded thru its power cordage, but is > > > grounded locally to your circuit. Even a 6" ground lead can and > > > often will show over voltage spikes where there really aren't any. > > > > I was just about to say that, but Gene beat me to it. Had an > > interesting discussion on the Tektronix listserv last week about > > exactly the same thing. The shorter the ground lead, the better. If > > you have a ground next to your test points, a short wire wrapped > > around the grounding section on your probe to the ground works the > > best - ie, your grounding lead ends up being about 1" or less in > > length. > > > > Tek used to make a grounding lead the snapped onto the end of the > > probe, and the lead on that was about an inch in length, or maybe > > less. > > > > Mark > > I have some coil springs that wrap around the probe tip, with a leg that > sticks out about the same as the probe tip. PITA to use but they work > really well when you need them. Comes with the 200 mhz rated probes from > MPJones. > > 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) > My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! > My views > <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> > The hardest thing in the world to understand is the income tax. > -- Albert Einstein > I was taught to respect my elders, but its getting > harder and harder to find any... > > > ------------------------------------------------------------------------------ > Free Next-Gen Firewall Hardware Offer > Buy your Sophos next-gen firewall before the end March 2013 > and get the hardware for free! Learn more. > http://p.sf.net/sfu/sophos-d2d-feb > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- *Leonardo Marsaglia*. ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
