It may not be enough. 45W @ 12V = 3.75a (W/V=A) Using the Casetronics PS as an example, it needs ~5a @ 12V, which is 60W. You'll need to add up the draw of each of your components (everything should have a label with this info on it, with the exception of the motherboard.) The USB touchscreen may also have an option for external power, which would reduce the load on this PS. If not, you can also look at using a self powered (rather than bus powered) USB hub.