Introduction: DIY - Mini Variable Power Supply 1,2-37 Volts - 2 Amper

In this Project we'll go tu built a Mini Variable Power Supply with a regulation range of 1,2-37 Volts, and a continuos max current of 2 Amper. You can use it with some other DC Power Supply, like old PC Power Supply, Small DC adapter of Radio or other equipment DC Power Supplyed, but for all of us that whant to work in full mobility, the regulator could be alimented with a Battery Pa.

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Step 1: Bill of Material

In the bill of material you will see the effective cost of the components. You can finde them on e.Bay or Aliexpress.

Bill of Material

  • DC-DC Step Down Converter LM2596 + Led Voltmeter --> 2,00$
  • 10 KOhm Potentiometer --> 0,25 $ (Or a multy turn version --> 1,00$)
  • Plastic Box (1,00$)
  • DC Power Supply or Battery Pac (9 - 12 - 24 - 36 Volt)


  • Welder
  • Pond
  • Screwdriver
  • Multimeter
  • Caliber
  • Hot glue

Step 2: Assambling the Circuit

The first thing to do is remove the 10 Kohm blu trimmer of the voltage regulation

With the trimmers removed we will going to connect the potentiometer.

Here we will attach three wire strings to each one. This wire does not need a particular diameter, but to facilitate welding to the board it will need to be fine enough

For those of you who will chose a 10 turn potentiometers, be careful that the variable terminal is the number 2

With the old PC power supply disconnected from the power, go to cut the output cable leaving a sufficient wiring harness, clear the poles and go check it with the multimeter the positive pole and the negative.

Do not trust of colors of the wires

Identified the poles you can go to connect them to the DC-DC Board.

The advantage of this board is the integrated voltmeter.

Check the wiring once again and when you are sure, switch on the power.

Try adjusting the potentiometers to make sure that you have connected it properly and that the voltage is adjustable

At this point we can switch to inserting our laboratory power supply into a box.

The size of the box depends from your final designe, Box, Lego Blocks ... Stay Creative!

Take the caliber and measure the diameter of all panel components.

Usually the bushes need a 6 mm hole and the potentiometer of 8 mm I miss you the task of finding the smartest way to do the holes for the measuring instrument.

WARNING: The output connection wire should have a sufficient diameter to carry the 2A

I have connect directly to de board an old Power Supply, but you could use a Male+Female connector to change the sorce and use the regulator with a dc power supply or a battery pac alternatively.

Connect the output to the Banana Bushes, and test all.

If all is OK, you can go to close the box

Very compliment! Now you have a Variable Power supply

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