12V/5V Power Supply Hookup Guide
The 12V/5V (2A) power supply is great for powering a microcontroller and an LEDs. In this tutorial, we will replace the power supply's molex connector with two male barrel jacks adapters.
To follow along with this tutorial, you will need the following materials. You may not need everything though depending on what you have. Add it to your cart, read through the guide, and adjust the cart as necessary.
You will need a soldering iron, solder, general soldering accessories, and the following tools.
If you aren’t familiar with the following concepts, we recommend checking out these tutorials before continuing.
How to Solder: Through-Hole Soldering
How to Power a Project
The power supply's pinout is shown below. The connector's molding will have numbers associated with the output to help identify the connection. You will also notice that the connector is polarized with the two chamfered corners.
The following table describes the molex connector's pinout and what color the wire may look like.
|Molex Pinout||12V/5V Power Supply||Notes|
|2||N/C||May Not Be Not Connected|
|4||+5V||"Black (or White)"|
Cut the cable about 1-2 inches from the molex connector.
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!
Then cut and strip a piece of hookup wire. Solder it to the 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.
Test the Output
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.
Label the Output
Using a Sharpie, clearly label the barrel jack connector's voltage relative to the output. Feel free to add an additional barrel jack when not in use.
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.
Certain power supplies have a lot of noise. While 12V/5V power supply works great with a microcontroller and a LED strip, it may not work as well when you attach a capacitive touch sensor to the system. The power supply lacks proper filtering and causes the potentiometer to have a lot of latency. You can try to add additional circuitry to fix it since the current power supply has a lot of noise. However, it would be easier to use two separate power supplies or a more robust power supply such as a Meanwell.
Resources and Going Further
Now that you've successfully got your 12V/5V power supply up and running, it's time to incorporate it into your own project!
For more information, check out the resources below:
- Molex Connector Pinout - Pinout of one power supply. Remember, wire color may vary depending on your manufacturer.
- Wikipedia: Molex Connector
- SparkFun Eagle Libraries - Check out the Eagle part for the molex connector in our libraries.
Need some inspiration for your next project? Check out some of these related tutorials that uses the 12V/5V (2A) power supply.
RGB Panel Hookup Guide
Large Digit Driver Hookup Guide
How to Build a Remote Kill Switch
Or check out some of these blog posts about power supplies