Comment by amelius
4 years ago
Kind of strange that they build scopes with ground tied to mains earth, as it is the source of so many problems and hazards. Letting the entire thing float would be the proper solution.
4 years ago
Kind of strange that they build scopes with ground tied to mains earth, as it is the source of so many problems and hazards. Letting the entire thing float would be the proper solution.
That's because the metal case can go live if there is an internal short. That's what that protects against. But agreed, that really caught me out. I had a blind spot for days due to the afterimage.
It's probably because touching the outer ring of the BNC connector (which is at ground) can become dangerous, yes.
So the best way to go about it is to use an isolated differential probe. Or use an isolation transformer to float your device under test, which is always a good idea.
Yes, I learned that the hard way that day.