About Charging via USB

[retsifp]

@Patrick1

Anyway in electronic engineering you whether have a fully isolated plastic casing not needing the third wire “pe” as there is very often now spot to actually connect it OR a design (metal casing like any tower pc psu) requiring a connection to protective earth.

This is not true. Some devices have a mains filter which needs the PE to conform to the rules of the European Economic Area. If you didn’t design the charger (or saw the schematics at least), you don’t know for what the PE is for!

@Patrick1

Just as you say, your notebook psu does not have the pe connected internally, Since it most probably does not keep a touch sensitive display, disconnecting the pe wire wouldn´t change a thing…but charging a smartphone at the end keeping a touch sensitive display surely does change a thing as I realized.

Is just nonsense. It’s not connected internally! So it doesn’t change anything and with or without touchscreen doesn’t matter. Please re-read what you wrote, it’s absurd.

And as I said, if disconnecting the PE changes something, it’s connected anywhere, so it’s needed and mustn’t be removed.

I personally don’t care what you do at home, but do not advise/tempt anybody disconnecting the PE wire. It’s just dangerous/weary of life.

And there are news about the touch-issue, it might be related to the voltage (and not to potentials, which is pretty surprising for me):

@smsm1

On the chargers where the screen doesn’t work while charging, I’ve been finding the voltage is dropping as low as 4.80 and possibly slightly lower. When no current was drawn these USB outlets give out 5.0 V. With the chargers where the screen is usable during charging the output voltage is normally closer to 5.2V when no current is drawn.

I’m wondering if there’s something in the electronics of the such that when the voltage goes below 5V, even just 0.2 V (a 4% reduction) is enough to cause the touch sensitivity to no longer work.