how to make a 240v 2A dc power supply? Answered

Can you tell us WHY it needs to be current limited to 2 amps.

In general items draw the current they need. If your wanting a safety limit put a 2 amp fuse in line with the supply.

Perhaps mains power, plus a simple rectifier circuit, half wave, or full wave, etc:

https://en.wikipedia.org/wiki/Rectifier#Rectifier_...

Then put that in series with one or two incandescent light bulbs,

https://en.wikipedia.org/wiki/Incandescent_light_b...

for to effect your current limiting.

I mean, what I have described is the, uh, "cheap and dirty" way to do this.

Actually, for not much more cost, you could throw in a TRIAC based lamp dimmer,

https://en.wikipedia.org/wiki/Dimmer#Solid-state_d...

to sort of throttle the mains power, and give you AC with less RMS voltage before the rectifier stage.

Regarding cost, cheapness, if you have ever gone shopping for a power supply, you might have noticed price tends to scale with power capacity. So that a little 5W thing to charge your phone is really cheap, and a 30 W brick for charging a laptop is maybe moderately priced.

When I multiply the two numbers in your spec together, I get 480 W, and that is kind of a big number. So there might be some sticker shock, if you actually go shopping for, and find offer for, a professionally made 240VDC, constant voltage, with 2A max current, power supply.