[Andre]

Andre Jute wrote:
Sander deWaal wrote:

Andre said:


The issue with HT on a public forum is never what experts can or cannot
do, but what a total innocent *must* do with his first DVM or scope, or
even his wirecutters

Let me explain my original thought:
Imagine measuring with a DVM... two leads, nothing else.
The ground of the DVM becomes the potential you connect it to.
But the DVM is isolated, double isolated.

When measuring with a scope the same principle would be ideal.
There are DVM/scope instruments, battery powered, isolated.
The real-world scope is mains-powered and not isolated.

The amplifier or whatever to be measured is connected to mains
as it should be, with ground.

Meanwhile I accidentally or intended touched the chassis of the amp...
It is grounded.

and here comes the tricky part, i admit.

and assume that the circuit 0 is tied to this chassis and go measuring
with the ground-wire of the probe tied to the 0 / ground / chassis
of the amp.

As long as I can rely on the scope not giving a failure of its own
I am safe.

When one ties the scope-probe-ground-wire to a mains-wire or +Ub
it is obvious he's asking for trouble.

Now could this be a startingpoint for a discussion.



I've had no problem with Andre Smeets, in fact he seems a good guy.

Indeed I try to be a good guy. Did send my apologies to the OP
for my postings might have been confusing to him.

Andre Schmeets