I took a 12 volt usb car usb adapter apart and wired it to a switch and a panel mounted female usb plug. The power supply is outputting 6.5 volts. This has me worried because I thought USB power was always 5 volts. Maybe once I plug something into it the voltage will automatically change to a the right voltage and current required by the device.
Also, this adapter says it is only compatible with Iphones. Does that mean anything else usb powered would not work?