Yeah, that's a cheap way to make a regulated voltage because 7805 was a bit cheaper than a LM317. These days there's probably not as much price difference. It works good enough if you account for the higher current out the ground pin on a 7805 compared to a LM317.
But it's still better than a DC plugpack and a 10 ohm resistor!
But it's still better than a DC plugpack and a 10 ohm resistor!
