LM317 Variable power supply with current control (Tip for 10 )

In this post I will show you easy to construct variable power supply using LM317 with some other components.

Final result is usable variable lab power supply with current control.

Current control is done using  LM393 comparator and shunt resistror.

Since I used one panel meter for voltage and current reading , I added LM358 OP amp to read current used by attached loads.

LM358 amplifies voltage detected on shunt resistor and amplify it to appropriate value which is set by variable trim pot.