A well designed and variable power supply for electronics hobbyists and DIY’ers is a must, you don’t want to spend a huge amount of money in batteries [On the long run]. A variable power supply can come in handy for testing and powering  any project you are building. The mentioned power supply ranges from 1.25V – 37V @ 1.5A using the famous LM317 voltage regulator. LM317T is a very famous IC and easily available in the market comes with 3 pins, supporting input voltage is from 3 volt to 40 volt DC and delivers a stable output between 1.25 volt to 37 volt DC.
It is a very high performance IC contains a builtin current limiter, built in thermal overload protection & safe area protection.
LM317T output current is 1.5A but many other low and high current models are also available in the market. So here is the schematic of a variable power supply best and ideal for lab use and also for many other purposes. The Output voltage is adjustable between 1.25v to 37v and the maximum output current is 1.5A. The circuit is very simple to build & contain less components but will give very best results. The output voltage is adjusted by 5.1K potentiometer. Use good heat sink with IC.