3 Simple Ways to
Share What You Make

With Instructables you can share what you make with the world — and tap into an ever-growing community of creative experts.

PhotosPhotos

Share one or more photos of a project, recipe, or whatever you've made, quickly and easily.

Get Started

Learn more & Get Tips

Step by StepStep-By-Step

Share your step-by-step photos with text instructions of what you made so others can do it too!

Get Started

Learn more & Get Tips

VideoVideo

Share your how-to video. You'll need your embed code from a video site such as YouTube.

Get Started

Learn more & Get Tips

Favorite

LM317 Small Power Supply

video LM317 Small Power Supply

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

30 comments

Oct 15, 2011. 5:32 AMselectauto says:

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!

Nov 1, 2011. 5:29 PMtim127 says:

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

Feb 1, 2010. 4:50 PMmnmc10 says:

hi can you list the parts needed?

Feb 2, 2010. 3:56 AMmacobt (author) says:

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

Oct 15, 2011. 5:10 AMsa104pm says:

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

Oct 15, 2011. 12:09 PMmacobt (author) says:

Cap values ere in micro farad.

Oct 16, 2011. 2:38 PMsa104pm says:

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

Jun 9, 2011. 12:19 PMalbertoelaria says:

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

Jun 9, 2011. 2:44 PMmacobt (author) says:

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

Aug 31, 2011. 4:52 PMoabdullah says:

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

Jun 10, 2011. 5:17 AMalbertoelaria says:

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

Jun 7, 2011. 6:42 PM

Electronics Man says:

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

Apr 11, 2011. 12:09 PMchicken12175 says:

what is the casing made of?

Oct 20, 2010. 5:39 AMtomx63 says:

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

Oct 13, 2010. 10:43 PMsantik says:

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?

thanks!

Oct 14, 2010. 11:09 AMmacobt (author) says:

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

Oct 14, 2010. 8:39 PMsantik says:

good current transformer? what do you mean by good current transformer?
isn't all transformer does the same job? step-up or step-down? But that's still AC right?

I tried using a wall wart directly to my project... but hum and AC noise comes in... very badly...
I thought of using a wall wart DC14V though this and I believe the maximum is 1.5V smaller which is 12.5V... what would be the 2 resistors be?

Mar 1, 2010. 2:46 PMtjmania2003 says:

What is the song in the background?, =)

... this project seems fun and could help me in my Electronic Circuits class, i have to build a power supply with an output of 12Vdc and output current of 0-2 Amps. Do you think this circuit will do the trick??

Good Job overall, the LED makes it seem even more legit.

Aug 1, 2010. 4:38 PMrntrrnc says:

The song in the background is Un altra te by Eros Ramazzotti. http://www.youtube.com/watch?v=wqvgONdQujM

Aug 1, 2010. 5:41 PMtjmania2003 says:

Much Respect! Thanks a lot!

Mar 2, 2010. 11:56 AMmacobt (author) says:

Thanks
I dont know what is the song,while I record the video the song play on my TV.
And wnat circut?

Mar 2, 2010. 7:34 PMtjmania2003 says:

Sure

you can send all the info on here please.

Thank you for everything!!

Jul 25, 2010. 8:26 AMhexinverter says:

Nice video! I have a question for you if you don't mind... If I were to use a 19v/3.42A wall supply, what capacitor values should I select? Bigger is better, to a point, right? Just want to make sure :) Of course I'll be using a higher current regulator. Thanks!

Jul 14, 2010. 12:09 PMhitachi8 says:

is there a way to protect my LM317 ? if i accidentally plug a 5amp thing on my Power supply , the LM317 gonna burn . is there a way to protect that ?

Jul 14, 2010. 4:07 PMmacobt (author) says:

hELLO If you conect three lm317 in parallel you can got 4.5A,but evryone must be on heat sink!!!!

Jul 11, 2010. 11:59 PMjackeytip says:

Thanks a lot. i already built one and it's working perfect. i use it for power my ardino board. Thanks