oscilloscope - connecting D signals with different ground

[crazyfox]

oscilloscope

Hi:

there is a question as below

According to the figure at right, the input couples of the two channels are both at DC mode. If we want to observe the voltages across the two resistors via CH1 and CH2 at the same time, is it feasible to connect A to 1, B, C to 2, and D to 3? What problems will occur if we do so? (Hint： All the black lines of Cables are “ground lines.”)

thanks

 

[dick_freebird]

oscilloscope

Depends on whether that ground symbol in the source,
is electrically common to the 'scope panel ground. It
could be. You might have to either use an isolation
transformer, or measure 1 & 2 and use difference
mode or post-process the dumped data (from a DSO).