Introduction: 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


vsegar (author)2016-01-16

video is private, so cant play it !!!

tobilogs (author)2014-09-12

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

devicemodder made it! (author)2014-07-29

I made mine a little bit bigger, also it has a fixed 5v output along with a variable voltage output. the battery seen is powering the meter. it is controlled by relay so it powers on with the power supply and shuts off with the power supply. voltage range depends on wall adaptor. current range is 1.27V DC to 16VDC

mnmc10 (author)2010-02-01

hi can you list the parts needed?

macobt (author)mnmc102010-02-02

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

trhone (author)macobt2012-11-03

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

macobt (author)trhone2012-11-03

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.

sa104pm (author)macobt2011-10-15

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

macobt (author)sa104pm2011-10-15

Cap values ere in micro farad.

sa104pm (author)macobt2011-10-16

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

albertoelaria (author)macobt2011-06-09

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

macobt (author)albertoelaria2011-06-09

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

selectauto (author)2011-10-15

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!

tim127 (author)selectauto2011-11-01

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

oabdullah (author)2011-08-31

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

albertoelaria (author)2011-06-10

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

Electronics Man (author)2011-06-07

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

chicken12175 (author)2011-04-11

what is the casing made of?

tomx63 (author)2010-10-20

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

santik (author)2010-10-13

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?


macobt (author)santik2010-10-14

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

santik (author)macobt2010-10-14

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?

tjmania2003 (author)2010-03-01

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.

rntrrnc (author)tjmania20032010-08-01

The song in the background is Un altra te by Eros Ramazzotti.

tjmania2003 (author)rntrrnc2010-08-01

Much Respect! Thanks a lot!

macobt (author)tjmania20032010-03-02

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

tjmania2003 (author)macobt2010-03-02


you can send all the info on here please.

Thank you for everything!!

hexinverter (author)2010-07-25

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!

hitachi8 (author)2010-07-14

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 ?

macobt (author)hitachi82010-07-14

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

jackeytip (author)2010-07-11

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

BIGBUG (author)2010-02-27

Your schematic, posted parts list and pictures do not match.

macobt (author)BIGBUG2010-02-28

 Yes I have made some changes for my power supply,but the basic schematic for adjustable power is that schematic.

Mike__ (author)2010-01-31

 Is the led is across C2 (output) ?

macobt (author)Mike__2010-02-01

 No,the led is across C1(input) voltage

About This Instructable




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