To monitor the signal I'm using a 100 MHz Diff scope probe. I've twisted the sense leads together to minimise coupling in that loop.
Z in the circuit is really low.... Mind you, I have made no provisions for the wiring that charges the energy ctorage cap. Maybe i should better tie thoese down. Since I'm using a "change over" relay, I wonder if what I'm seeing is to do with the cap ESR being too low.... I'm using Mica Caps. The spike I refer to looks just like the spike on an ESD waveform in the IEC standards. Cheers, Derek. robert Macy wrote on 3/23/2004, 1:03 PM: > Make certain the signal is real and not an artifact. > > I once chased a signal for four hours before I discovered > it was the scope ground "bouncing" ..well that, and other > stuff. Differentially, the signal WAS NOT THERE. > > - Robert - > > Robert A. Macy, PE .. [email protected] > 408 286 3985 . . . .. . . fx 408 297 9121 > AJM International Electronics Consultants > 101 E San Fernando, Suite 402 > San Jose, CA 95112 > > On Tue, 23 Mar 2004 09:57:30 -0800 > "Price, Ed" <[email protected]> wrote: > > > > > > -----Original Message----- > > From: Derek Walton [mailto:[email protected]] > > Sent: Tuesday, March 23, 2004 6:53 AM > > To: [email protected] > > Subject: Tweaking a transient Generator > > > > > > Good day all, > > > > I've been developing a damped sine generator to perform > > the DO-160 lightning > > test, and have had some reasonable success. However ( > > there is always a > > gotcha ), the leading edge of the 1 MHz ring wave has a > > very short ( around > > 10 nS ) spike on it. I have tried a number of things to > > kill the spike, but > > to no avail. Does anyone have suggestions on what causes > > this, and ways to > > eliminate it? > > > > I have strived to keep stray inductance small, very > > small, maybe too > > small..... > > > > The switch is a high voltage vacuum relay. > > > > -- > > Derek N. Walton > > L F Research > > Poplar Grove, IL 61065, USA > > > > > > > > Derek: > > > > Why not put up a schematic, plus a couple of > > multiple-angle photos, and give > > us a link so we can see what you are doing? > > > > Ed > > > > Ed Price > > [email protected] WB6WSN > > NARTE Certified EMC Engineer & Technician > > Electromagnetic Compatibility Lab > > Cubic Defense Applications > > San Diego, CA USA > > 858-505-2780 (Voice) > > 858-505-1583 (Fax) > > Military & Avionics EMC Is Our Specialty > > > -- Derek N. Walton L F Research Poplar Grove, IL 61065, USA This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ieee-pses.org/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
