21 Nov
2012
21 Nov
'12
9:38 p.m.
Keith Monahan wrote:
My DUT for the most part is a commodore amiga that has
an external
120v to +12v,-12v, and +5v power supply. I'm not intending on opening
supplies, troubleshooting/repairing them or generally touching
anything that has live mains power following through it.
Generally speaking, the power supply (internal or external) for any
UL-listed computer (and most others) is isolated from the mains power,
so there's no problem with probing it with a scope or logic analyzer.
It's only when you're working on the power supply itself that you'd be
likely to run into trouble.
A common situation where people have damaged their test equipment is
working on a "hot chassis" (non-isolated) television. I haven't ever
seen a hot-chassis solid-state computer. I don't know whether many
tube-based computers were hot-chassis.