USB Power Line down / up for USB Ventilator

[levi]

Assuming you mean 500mA at the end there, sure. A relay is just a switch like any other, so power in = power out.

 

[rohezal]

 I ordered the USB Relay and then Ventilator today. Lets hope for the best. Thank you all again for your advice .

 

[HelenF]

Maybe you already know this, but to avoid cutting the fan (or your second power supply if you have a USB type one), take a look on eBay for cheap USB cables with the right sockets to cut up instead.

I mean things like this for the fan: http://www.ebay.co.uk/itm/400570035250

Thinking about it, a lot of USB type chargers have a detachable USB cable anyway. So the best deal might be a longer version of the one I linked, cut it into two parts and use both.