3Amps Adjustable Power Supply Provides 1.2V to 15V DC LM1084-ADJ

Simple power supply circuit provides variable output voltage 1.2V to 15V DC and load current up to 3 Amps, onboard trimmer pot provided to adjust the output voltage. Output capacitor C3, C4 provided for transient response, the circuit can take DC input as well as AC input, maximum DC input 15V DC and AC input 12V AC. LM1084-adj IC is heart of the project.

LM1084-ADJ Data Sheet


  • Output 1.2V to 15V DC
  • Input DC 15V DC
  • Input AC 12V AC
  • Load Current Up to 3Amps

Note : The project also can be used with LM1085-ADJ, LM1086-ADJ, AND LM317-ADJ

Note : Higher input and output volatge possible with few changes, input filter capacitor volatge , higher current bridge rectifier can provide higher current up to 5amps with LM1084-adj. refer data sheet of LM1084-ADJ



The LM1084 is a regulator with a maximum dropout of 1.5 V at 5 A of load current. The device has the same pinout as TI’s industry standard LM317.

Two resistors are required to set the output voltage of the adjustable output voltage version of the LM1084. Fixed output voltage versions integrate the adjust resistors.The LM1084 circuit includes a zener trimmed bandgap reference, current limiting, and thermal shutdown.

Refer to LM1085 for the 3A version, and the LM1086 for the 1.5A version.