Hi all,
Do u know how to make a 0-10V adjustable DC power supply, supplied from 240 Vac?

 

AC->stepdown transformer->three terminal regulator->out

Amperage will be of concern as this does not provide much but this is an example.
In the example you would want to replace the transformer and the 7805 with probably a 240VAC to 24VAC transformer and a 7810 if you can find one. You'd get rid of the other outputs and just use the 10V three terminal regulator

Tutorial on linear power supplies

If you need hyper efficiency for some reason then you'd be more interested in switching supplies.