07-13-2010, 12:16 AM
I think powering a 1 amp device with a 10 amp power supply is kind of like drinking out of a fire hose. That fire hose is going to put out a lot more water than you can possibly drink. The device is going to determine how many of the available 10 amps are actually used. The rest of those amps will just sit there until some other device needs them. a short circuit will demand all of the power that power supply will put out and then some if it can. That is why you need a fuse in each circuit sized to slightly exceed the power demand of whatever is running on that circuit. If you put a 2 amp fuse on a circuit with a device requiring 1 amp, you will have twice as much power as needed for the device, but the 2 amp fuse will blow and shut down everything in the event of a short before other damage is done.