LM317 (positive voltage regulator) and LM337 (negative voltage regulator) output series-connected power transistors powered by the 5k and 20k potentiometer binary (stereo) type if you use the + and – output of the current and voltage settings set equal... Electronics Projects, Adjustable voltage and current power supply LM337 LM317 "power electronic projects, power supply circuit, power supply project, " Date 2019/08/02