12V/5V Power Supply Hookup Guide

Contributors: bboyho
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Hardware Hookup

Breakout Board

To easily connect to the 4-pin connector, we recommend using the ATX power connector (4-pin). For more information, check out the tutorial.

ATX Power Connector (4-Pin) Breakout Hookup Guide

October 10, 2019

Do you need to power a project with 12V and 5V from one wall adapter? The ATX power connector breaks out the standard 4-pin computer peripheral port for your 12V and 5V devices!

Hacking the 4-Pin Connector

Otherwise, you can modify the cable and use a polarized connector of your choice. This requires more time and effort. The following images use the older 12V/5V power supply so the wires may be different depending on the manufacturer. Cut the cable about 1-2 inches from the 4-pin ATX connector.

Cut cable

Cut into sheath with the flush cutter. Pull it back just enough so that you have enough room to work with the wires. Be careful not to cut yourself!

Cut Sheath

Strip the power supply's three wires. The wires are stranded so feel free to tin the wires by adding solder to the tips.

Tin Wires

Then cut and strip a piece of hookup wire. Solder it to the ground wire.

Refrence Ground Wire

Braid the wire and insert into a barrel jack connector. Secure the wires in the screw terminal with a Phillips head. Feel free to add some heat shrink or electrical tape to the connection at this point.

Tighten Screw Terminals

Test the Output

If you modified the cable with barrel jack connectors, power the power supply and test with a multimeter to verify the voltages. Usually power supplies are center positive so make sure that the wires were inserted correctly. Adjust as a necessary for your system.

Test outputs

Label the Output

If you modified the cable with barrel jack connectors, we recommend that you clearly label the barrel jack connector's voltage relative to the output using a Sharpie. Feel free to add an additional barrel jack when not in use.

Label Barrel Jacks

Power Your Circuit!

Connect the power supply to your circuit and power it up! I personally use the power supply as a tool for basic testing. Usually the 12V side is connected to an Arduino's barrel jack. The 5V output is used for more power hungry loads such as the the RGB LED Matrix or a few meters of addressable (WS2812B, APA102, etc) LEDs.

RGB LED Matrix 32x64 Powered with the 12V/5V (2A) Power supply

Arduino Mega 2560 and 32x64 RGB LED Matrix Powered by the 12V/5V Power Supply