Phone's touchscreen goes awry when connected to a certain charger

[Alison]

Hello everybody,

I recently bought this neat power station with four mains outlets and three USB that plugs right into a normal duplex wall plate.

I can charge my Nexus 7 off the USB ports just fine, but when I plug my Nexus 4 in the touchscreen goes slightly awry and randomly misses touches.

Could this be due to a high frequency crap on the DC output? Would I fix this by replacing the output capacitors with higher valued ones? Unfortunately I don't have an oscilloscope so I can't see how noisy the outputs are

Thanks!

[Rigby]

I've had that happen when the wattage isn't sufficient to both run the device and charge it.  The charge indicator would cycle on and off at about 1Hz.

Most USB chargers can deliver 5W of power, but few are rated for 10W, which some devices require. 

I would check the ratings on the chargers that came with the devices and see if the new wall outlet thing can deliver the required power.

[echen1024]

No, simply not enough wattage.

[Alison]

Yep, my phone acts totally normal when it's the only thing plugged into the outletthingy's usb ports. I'm disappointed because my old USB outletthingy could charge my phone and tablet at the same time with no ill effects and was also rated at 2.1A.

I don't think it is worth to return the new outletthingy, I'll just live with it I guess.

[amyk]

Maybe it lies about its current rating...

[tan98010]

It is most likely there is a AC leakage, i faced this problem before, i solved the problem by grounding the negative at the DC to the mains ground.

[DavidDLC]

That is because it is a noisy charger

It happens with different chargers, different phones, that is why manufacturers recommend you to use approved chargers only.

David.