Here I was trying to find a way to convert 24v (Industry default) to 5v for an atmega microcontroller.
I know you can use a buck converter, but that adds some costs, space, etc.. etc... You know.
The other option (Linear regulator from 24 to 5) is feasible, as the whole system I'm trying to implement uses only about 50ma, but what bothers me is the heat inside the case where the pcb goes. Also, wasting 19v into heat bothers me.
So it came to my mind about an option I couldn't find anywhere, and I don´t really know why I couldn~t find it.
So, my idea is to first use a -18 regulator:
Gnd + 24 ==> 7918 regulator ==> Gnd + 6v + 24v
Use the Gnd and 6v ==> 7905 Regulator ==> Gnd + 5V.
Like this, you waste only 7v instead of 19v, so, why no one suggests this? Is there any "catch"?