Can't find a 7805 but need a regulated 5V supply?
Top transistor is TIP29 or similar.
Others can be 3904, 2222, pretty much any NPN.
.47 ohm resistor should be around 2W.
Variable resistance used to fine-tune voltage when using real world components with tolerances.
Top right horizontal switch simulates connecting a load.
Vertical switch illustrates the short-circuit protection.
