UncleMonty wrote:I really should have gone to college instead of technical school...

Well, then instead of 35 kV HV cabinets, you can help me troubleshoot our locomotive's cranking inverter which involves looking for a 1-2 V signal on top of 800 V wrt ground; I was able to see it by using an isolation transformer and a cheater plug to float the scope, but still got a lot of nice sparks between the ground tab of my cheater plug and the ground pin of the adjacent outlet on the iso-trans
Next time I need to do that, I plan to have the lab build my own diff-amp circuit to knock the 800 V down to 10 V, then step it back up again 40X...
I just hope I don't have to do it in the field for the latest problem - if somebody ends up going out, they've got the choice of driving 8? hours with a car load of stuff, or trying to get it through airport security these days
And I'm the one who gets stuck with it even though I'm a signal electronics engineer, not power electronics, since I seem to be the only one left around here who knows how to run a scope
Why is it the only secure jobs are the ones you don't want?
Ron, BSEE 1981