Thanks all for replying. It seems that we are all talking about the same thing (in a way)
The circuit in question has ground at -90VDC referenced to true ground. I will be safe!
Could the OP not also use an isolation transformer on his oscilloscope itself? That seems more preferable to me, because you wouldn't need an isolation transformer that supplies a ton of power, and you don't worry about inaccurate amounts of voltage drop and such.
by Jake Hertz
by Jake Hertz
by Jake Hertz
by Jake Hertz