Turning AC (alternating current) into DC (direct current) is fairly easy.. turning DC into AC is a major PITA!
I can assure you that it will be easier (and most likely cheaper in the long run) to find the right king of PS somewhere on the internet.
Do you know exactly what the power requirements are for this device?
As far as an AC device being totally non-functional when supplied with DC .. it depends on the device.. some simple things like some computer speakers will actually work with DC when AC is specified. The best way to test is to try.. as long as you get the Voltage correct and the amps fairly close.. otherwise you will let all the magic smoke out of the electrical components inside the device!
