Make a simple 12 volt power supply

Have you ever needed a 12 volt power supply that can supply maximum 1 amp? But trying to buy one from the store is a little too expensive?

Well, you can make a 12 volt power supply very cheaply and easily!

I needed a 12 volt power supply for my project, the SSTC (Solid State Tesla Coil), and also made this instructable because it might be use full to someone...

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Step 1: Things that you will need...

Things that you will need to make this power supply is...

Piece of veroboard
Four 1N4001 diodes
LM7812 regulator
Transformer that has an output of 14v - 35v AC with an output current between 100mA to 1A, depending how much power you will need. (I found a 16v 200mA transformer in a broken alarm clock.)
1000uF - 4700uF capacitor
1uF capacitor
Two 100nF capacitors
Jumper wires (I used some plain wire as jumper wires)
Heatsink (optional)

You should be able you get most (maybe all) of the parts at Radio Shack or Maplin.

DeShark says: May 12, 2013. 7:34 AM

I know this was over 5 years ago, but you probably wanted to use a different transformer to reduce the voltage further. This would cause the power dissipation of the voltage regulator, keeping it cooler..

raheelcivilline says: Apr 8, 2013. 10:34 PM

he bro you should use breadboard first to make pre-circuit....p

raheelcivilline says: Apr 8, 2013. 10:30 PM

no problem one of my friend also burnt his transformer in lab :P and he has to submit power supply project and he buy new one dn't be disheart :P

smriti.sonkar says: Apr 8, 2013. 7:33 AM

i burnt my transformer when i made this supply...i dont know what went wrong..it was really disheartning

chetan_m.p says: May 4, 2011. 4:48 AM

what is the voltage of those capacitors..

tristantech in reply to chetan_m.pDec 31, 2012. 2:52 PM

The "voltage" of a capacitor usually refers the the maximum working voltage before the capacitor components degrade. The rectifier outputs about 16V, so use capacitors rated for at least 30V for safety

iTixle in reply to tristantechDec 31, 2012. 6:28 PM

The rectifier will actually output a bit more. The rms value (average value) of the transformer is 16 volts, however during rectification the voltage output is actually the peak voltage of the AC input which would be the rms value x 1.41 or around 22 volts :)

fatfoohy says: Jan 29, 2010. 5:50 AM

could i run multiple 12 volt circuits off of this power supply at the same time? i'm looking to run 4 preamps and a stereo 15x15W amp off of it

tristantech in reply to fatfoohyDec 31, 2012. 2:54 PM

Just put them in parallel. This circuit will not adequately power a 15W amplifier, however, so don't use it.

tjgamer1987 says: Jan 14, 2012. 8:26 PM

hey, nice circuit! i was wondering, im doin tha same type and i wanted 2 know wat did u hook your centertap connection wire and the primary wires from the transformer to?

tristantech in reply to tjgamer1987Dec 31, 2012. 2:50 PM

The primary goes to a 120V outlet. The center tap is not connected.

tonygoffe says: Feb 15, 2012. 1:16 AM

Hello... Can someone do an IInstructable on how to "DE-SOLDER" rectycled componenets from a circuit board ?? ....PLs? PLS? pls?

tristantech in reply to tonygoffeDec 31, 2012. 2:49 PM

We have a search box that allows you to find instructables like that. Trust me, there are many.

chnaveed.alam says: Jun 23, 2012. 6:38 AM

hello there i have a 12 v power supply it contain only one 1000uf capacitor and bridge problem is it shows output morethen 12 near to 16 etc Question is can i reduce it by adding a resistor if yes then how to calculate resistor for this circuit and where to place it
i hope to hear from you soon

tristantech in reply to chnaveed.alamDec 31, 2012. 2:49 PM

You need a voltage regulator IC. Resistors are not for burning off voltage

mrmerino says: Oct 15, 2012. 9:12 AM

Holy cow, this comment section is just packed with the neediest electronics noobs anywhere on the internet!

tristantech in reply to mrmerinoDec 31, 2012. 2:45 PM

Yep. I like the comment below about the inductor values or the ones where people ask for a version that supplies ONLY 200mA.

ache003 says: Nov 24, 2012. 6:40 AM

what is the voltage rating of the 3300microfarad capacitor? please answer..

ahmedali says: Jul 24, 2012. 8:44 AM

how can i change current to my desire value??? plz plz tell me
for example if i want to change 1A to 500mA from above mentioned circuit

mrmerino in reply to ahmedaliOct 15, 2012. 9:10 AM

Relax. Current follows voltage. If you have 24 ohms across the output, it'll sent out .5 amps.

altaf hussain says: Aug 17, 2012. 12:07 PM

how to built the body of the power supply.

thanks.

ahmedali says: Jul 24, 2012. 9:08 AM

how can i change value of current to my desire value like 500mA from 1A???

ahmedali says: Jul 24, 2012. 8:45 AM

plz reply as soon as possible

chnaveed.alam says: Jul 8, 2012. 2:14 AM

u did'n mention cap voltage

Bharat Babbar says: May 22, 2012. 3:45 AM

this is a solution of my problem..... thank you up-loader....

Zinozee says: May 14, 2012. 7:43 AM

Lovely, we have a very similar project in skool rite now, hope to use this effectively. thanx

Zinozee says: May 14, 2012. 7:43 AM

Lovely, we have a very similar project in skool rite now, hope to use this effectively. thanx

offtherails2010 says: Jan 12, 2012. 1:50 PM

Awesome Circuit!

I'm only just starting out in electronics and still trying to wrap my head around reading schematics but with you physically showing the finished product & components pictures/list makes it even easier for someone with very little experience to construct!

A Major Thank You !!

Um, i wonder if you'd be able to help out on a very similar circuit for me please ?

Im trying to get my four batteries (3.6v each in series) to power my wireless pinhole camera's receiver but dont know how to get the power down from 14.4v to 12v (No more than 500mA), DC to DC...

Please would you be able to help in this regard ?

Many thanks in advance if you can help this troubled-soul !