Introduction: Simplest and Cheapest Adjustable Power Supply

Here is a very simple adjustable power supply I built for powering my projects. If you're into electronics sooner or later you're going to need one. This particular design is very easy and cheap to make. Plus it's based on a ready made module which simplifies everything even more.

Parts needed:
LM2596 module (plenty of them available on fleabay - average price just over 3$)
AC adaptor (preferably one that can output at least 24V, but not more than 35-40V)
Some wires and male headers



Jan_Henrik (author)2014-05-05


kokpat (author)2014-03-16

I found one in China, with 7 segment display voltage input and output.

For reference.

Input voltage 4.0 to 40V; Output voltage 1.25 to 37V

Max output current is 3A, stable current is 2A.

It is about RMB$16, i.e. about US$3.0

stubbsonic (author)2014-03-13

I'm learning electronics, and was wondering about current output. Will this output the same current as the source supply? Is there a way to regulate current & voltage (perhaps with a pot?)

kerimil (author)stubbsonic2014-03-14

This only regulates voltage. There are ways to limit current in any circuit - look up 'current limiting'. If you're new to electronics I suggest getting yourself familiarised with datasheets - they have plenty of information and even example circuits. Here's one on the lm2596 ->

Also... there exist modules based on the LM2596 that also limit current - they are more expensive, but I guess some of you might prefer an off the shelf solution -> google 'LED Voltage and current display LM2596 DC-DC Step Down CC-CV Adjust Power Supply'

stubbsonic (author)kerimil2014-03-14

I think I need an interim step to the data sheets. The example you provided was beyond my level of understanding. I have a few beginner electronics books and know where to find some of these answers. It sounds like it's not necessarily a simple add-on to control the current.

kerimil (author)stubbsonic2014-03-14

The simplest way to limit current is to use a resistor. There are plenty of examples on the internet. It isn't the most efficient method (there are losses), but definatelly the simplest one.

isnacku (author)2014-03-12

Mate that brave move, well done.

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