DIY Cheap and Simple Breadboard Power Supply

I've been using my Arduino UNO as a simple power supply for my electronics projects as it's easy to set up and easy to work with a breadboard. the problem is that it's not that powerful and it might even damage the Arduino when used for a prolonged time. I'm sure many of you are doing this too but we must know the dangers of it. The UNO R3 uses AMS1117 5v and the LP2985-33DBVR regulators to keep the voltages stable. Because they are linear regulators they produce a lot of heat while drawing a lot of power. The 3.3v regulator used here is only rated for 150mA, so it is immediately evident that we should at least upgrade the 3.3v rail. The AMS1117 5v regulator can output close to 1A but it gets very hot even at around 500mA, this chip might interfere with more sensitive components of the UNO when it's been running for several hours of troubleshooting or experiments you are doing. With this premise, I designed a simple budget-friendly power supply that can power a breadboard from a 12v source. I designed this with Linear Regulators as well but the ones used here are more powerful, if I had used switching buck regulators instead, the parts and the circuit would have been more expensive and complex. This is an easy-to-follow circuit for anyone who is starting out with electronics.

NOTE:- The power rail spacing for the design of the included PCB Must be tweaked for your breadboard power rails otherwise the pins won't go in. I have two cheap breadboards of two sizes I made it so that it would work both easily and simultaneously.

Parts Lists

• AMS 1117 3.3v regulator x 1
• L7805 x 1
• 7812CT x 1

• Male headers x 12
• Long Male or female headers x 8 (if its hard to find use normal male headers with the modification I mentioned in step 2)



• DC barrel jack x 1
• Latching switch (DPDT ones have the correct layout) x 1
• LEDs x 2
• 10K resistors x 2

• 10uF Electrolytic capacitor x 3
• 100uF Electrolytic capacitor x 1
• 100nF Ceramic capacitors x 4



I'm using EasyEDA for the Schematic and PCB Design, I recommend you open the project in EasyEDA and then export files to your preferred software. You must tweak the PCB files as many cheap breadboard designs are not standardized. The files provided have 52mm and 45mm distanced power rails. This PCB is optimized for the bottom layer since dual-sided PCB manufacturing is pretty expensive. If you are going the one-layer route use copper wire to jump the four holes according to the schematic (this part can be messy if you mess up the connections please refer to the schematics carefully).

Links for schematics :- https://oshwlab.com/chiranapcb/breadboard-powersupply

:- https://easyeda.com/editor#project_id=ea2dfab26f4e4f00abcca70c02911d6c

Using a prototyping board like mine is budget-friendly but the structural stability, ease of use, and cleanliness of a PCB are unmatched. I did not have the standard locking switch used in the schematic, they were pretty hard to find in my region, so I had to use an external switch. NOTE the DC barrel jack does not have standard-sized legs here so you must modify the holes of the prototype board to be able to mount it correctly. If you can find the Long female or male connectors I mentioned above you can modify 8 male header pins so they will reach the the other side with the correct length by pushing the plastic pieces towards the end.

Using a 12.6v or higher power supply is recommended as the 12v regulator needs a higher voltage than 12v to function properly.

The outputs are selected using the 6 jumpers on each side (so the Left rail and the Right rail can have different voltage outputs) by using a 2 pin jumper and shorting the two pins we can get the output. To turn off one or both sides of the power supply all you have to do is remove the jumper(s).

Known issues - the regulators will get hot after a while but these regulators are reliable and pretty secure in my experience.

Feedback is much appreciated thankyou.