During lab exercises at study my friend sitting next to me tried to see with the scope the voltage at diode in thyristor circuit. One of three phases at 3-rd floor of Electronic department dead. The lab teacher told him to think once more what he is doing. So he thought some time, than reconnected his scope and his thyristor circuit to another phase and ... next phase dead. After this second experiment whole his circuit looked like it was painted with black spray. When he suddenly jumped back of his desk I looked there and sow some copper paths separated from his PCB and firing on the desk. 10 or more years later I was travelling by train. Three students were sitting in the same compartment. At one moment one of them began to tell my friend's story to the others. I was seriously surprised.
Piotr Galka ----- Original Message ----- From: "Pettit, Ghery" <[email protected]> To: <[email protected]> Sent: Tuesday, March 10, 2009 5:40 PM Subject: RE: scope probe gnd > Or there were the old scopes where you used patch cords and banana jacks. > We had what was left of the power cord for one such scope hanging in the > front of the motors lab in college that showed the importance of having > your setup checked before applying power. Seems the hot and ground leads > to the scope from the motor being measured got reversed and the 120 VAC > supply was bypassed to ground through the green wire in the power cord. > For a short period of time. Then the green wire acted as a fuse. That > cord was NOT repairable. And, NO, I was not the culprit. Didn't happen > on my watch. > > Ghery Pettit > > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of Ralph > McDiarmid > Sent: Tuesday, March 10, 2009 9:35 AM > To: [email protected] > Subject: RE: scope probe gnd > > Once for me as well. I never forgot that lesson. > > > Ralph McDiarmid, AScT > Compliance Engineering Group > Xantrex Technology Inc > > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of John > Woodgate > Sent: Tuesday, March 10, 2009 5:47 AM > To: [email protected] > Subject: Re: Surge testing Questions > > In message > <9d04b979323dcd428297dda95108893e0120c...@bb-corp-ex2.corp.cubic.cub>, > dated Tue, 10 Mar 2009, "Price, Edward" <[email protected]> writes: > >>What, you never had that happen?! > > Only once - so far! > -- > OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk > Things can always get better. But that's not the only option. > John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. To post a message to the list, send your > e-mail to <[email protected]> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieeecommunities.org/emc-pstc > Graphics (in well-used formats), large files, etc. can be posted to that > URL. > > Website: http://www.ieee-pses.org/ > Instructions: http://listserv.ieee.org/request/user-guide.html > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to > <[email protected]> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieeecommunities.org/emc-pstc > Graphics (in well-used formats), large files, etc. can be posted to that > URL. > > Website: http://www.ieee-pses.org/ > Instructions: http://listserv.ieee.org/request/user-guide.html > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to > <[email protected]> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieeecommunities.org/emc-pstc > Graphics (in well-used formats), large files, etc. can be posted to that > URL. > > Website: http://www.ieee-pses.org/ > Instructions: http://listserv.ieee.org/request/user-guide.html > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
