Hello all!
I recently bought a Hantek DSO5102P. Today, I measured the main voltage (220Vrms, 50Hz) in my office (using an insulation transformer, obviously) and what I see on the screen changes significantly in case I use AC or DC coupling.
In details, when using:
DC coupling: I read 592Vpp, -296Vmin, 296Vmax
AC coupling: I read 664Vpp, -332Vmin, 332Vmax
the testing condition is the same, i.e., probe connected to the output of the insulation transformer. the only thing that changes is coupling, AC vs DC.
I know that AC coupling exploits HPF and so, 50Hz could be attenuated. However, I am experiencing exactly the opposite. When using AC coupling, I see increased voltages.
What's going on here guys?
I am attaching two photos showing the oscilloscope and the measure.
Thanks a lot in advance for the help!
best,
Franco Maria (from Tuscany, Italy)