Is the big thing in the middle the capacitor in question, or is that the transformer?
I found a laptop power supply listed at best buy that is 19V, 100W for something like $30. Might be an easier way to go, I'm thinking? If the output is controlled enough to not fry a computer, I imagine it would be ok for enlarging too?
Laptop power supply is not a very good choice because it does not regulate voltage well. It is so because it's a charger and not a power supply. The battery acts as a voltage regulator.