I try to test the start up current with oscilloscope voltage probe using a shunt resistor (0.1 ohm), see the figure for connection, i put CH1 and CH2 probe on both side of the shunt and leave the probes ground clip not connecting to anything. On the scope i set the display to MATH (CH1-CH2). But all I get is a huge noise.
Am I doing the correct way? Should I leave the ground clip open or connect to the same ground of the load?
Am I doing the correct way? Should I leave the ground clip open or connect to the same ground of the load?