LM317 Small Power Supply





Introduction: LM317 Small Power Supply

About: My name is marjancho and I love electronics,makeing gadgets,hack and pranks.

This is LM317 small power supply.The input voltage must be at least 1.5 volts greater than the output voltage.
The output voltage is adjustable between 1.25 and 13.5 volts if the input is 15 volts,maximum current
limit is 1.5 Amps
A heat sink will be required for most  aplications however
Here are pictures to see the power supply and schematic



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video is private, so cant play it !!!

What if I want to change the maximum output to 24V? Which component should i change?

The parts:
LM317 regulator
Heat sink for LM317
DC in power jack
Capacitor 2200mf 25v
Capacitor 4.7mf 25v
Led diode
On,off power switch
Pot 4.7K
Output conectors


i willing to pay for someone to show me how to do this

I would like to help,but I dont have time to record video how to do it,maybe you should search on youtube how to make it.

I'm a bit confused on your cap values... are they mf as in milli farad, or uf micro farad???

Cap values ere in micro farad.

okay thanks. I ended up not needing to use caps though. Im just building a simple LED driver (lamp for the license plate on my motorcycle) and only required resistors

you forgot to mention the resistor value ???
is there one?

Yes I forget,the resistor is 240 ohms 1/4watt

PLEASE PLEASE Write Step by step instructions on how to buid this curcait. I really need this. i don't no much about electonics but i have eye's and ears and I can follow intructions and have a good online tool called google for extra resurch. PLEASE Place step by step intructions here!

1 reply

if you get the lm327 at radio shack there is a pretty simple schematic on the bad and r1 is the resistor and r2 is the potentiometer

i have to do a variable power supply 0-12v....can i use LM137??

can i use 50k pot instead of 5k? do i have to change the resistor value from 240 to less.

i am new to electronics :( need some help

Awsome project but you might consider publishing a full step by step instructable because it would really help with the building.

nice job indeed. can you update the schematic to include the LED?

I intend to use it on a audio amplifier... I have tried connecting a router supply to it... and there is hum... so does a laptop adapter...

will this project make the voltage constant? and no hum?


1 reply

You can use this power source for your amplifier,but you must have good curent transformer.