Caveat: Lab 2

One group has just stumbled over a problem others might as well encounter:

When using scope probes their ground reference (little black crocodile clamp at the scope probe) MUST be connected to GLOBAL ground!!! That is NOT to any other DC voltage, like e.g. your point of operation voltage (even if that would be very convenient).

The reason: these clamps are internally connected to global ground and if you try to connect them to another voltage they will try to drag that voltage to global Gnd.

If this is unclear, talk to Thomas or come knocking at my door.