Linear and switching power supplies circuits design

Using two three terminal regulators like LM337 and LM317 we can design a very simple high efficiency power supply electronic project using few external electronic parts.
The LM317 and LM337 are adjustable 3-terminal positive , respective negative voltage regulators capable of supplying wide output voltage range at a maximum output current of 1.5 ampere.

This LM317 adjustable power supply electronic project will provide a wide output voltage range from 1.5V up to 30V by selecting two resistances.
You can draw up to 1.5A from the LM317 , but if you need a higher current you can use an LM338T rated to 5A.

Using LM317HV adjustable 3-terminal positive voltage regulator can be designed a very simple high current variable power supply circuit .