If you need, say, a 5V regulator, you grab a 7805, add a capacitor for stability, and send in enough voltage for the regulator to work with. Cheap and easy. However, the part is not without its ...

We’re quite sure that all hobbyists have used the 7805 voltage ... picture above such a regulator is composed of very different elements: transistors, resistors, capacitors and diodes, all ...