Switch USB device between two PCs?

Thread Starter

AlbertHall

Joined Jun 4, 2014
10,390
Does anyone know of any problem with using a DPDT relay to switch USB receiver part of a 'wireless desktop' (mouse/keyboard) between two computers.
The USB power from the PCs would be combined with schottky diodes (or possibly MOSFET 'perfect diodes') to power the USB receiver, relay and the circuit driving the relay.
 

wayneh

Joined Sep 9, 2010
16,399
Does anyone know of any problem with using a DPDT relay to switch USB receiver part of a 'wireless desktop' (mouse/keyboard) between two computers.
The USB power from the PCs would be combined with schottky diodes (or possibly MOSFET 'perfect diodes') to power the USB receiver, relay and the circuit driving the relay.
I wouldn't connect the grounds of the two USB power supplies unless/until you can verify that no current will flow from one to the other. I'd start with a 1K resistor between the two grounds and look for a voltage across it. Drop it to 100Ω and repeat.
 

Thread Starter

AlbertHall

Joined Jun 4, 2014
10,390
I wouldn't connect the grounds of the two USB power supplies unless/until you can verify that no current will flow from one to the other. I'd start with a 1K resistor between the two grounds and look for a voltage across it. Drop it to 100Ω and repeat.
Good point. I will have to check that.
 
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