A switching AC to DC power supply is an ideal accessory to to load software or troubleshoot your carputer outside of the car. You can pair it with our M1/2/3-ATX power supply adapter to simulate a key on/off event in the car to see how the pc will start up and shut down. The 5a output is sufficent for all Atom and AMD Fusion based computers. For higher wattage core i3/5/7 or 775 socket based systems we suggest the 8a or 10a models.