Learn enough to design a switched mode power supply. Then you can get the efficiency up and the heat out of the IC's.
You could also use relays and switch the primary and secondary windings to lower the DC input voltage to the adjustable regulator.

 

Learn enough to design a switched mode power supply. Then you can get the efficiency up and the heat out of the IC's.
You could also use relays and switch the primary and secondary windings to lower the DC input voltage to the adjustable regulator.

If I rememeber right, that is much more complicated. I'm only an amateur

 

I take back my previous statement. It's rather simple to make one. I only have a few questions though. Is a line filter needed? And is a PFR filter needed?