On Monday 11 February 2013 12:41:34 Mark Wendt did opine: > On Sun, Feb 10, 2013 at 6:59 PM, Gene Heskett <[email protected]> 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
