Report DIY Arduino Power Supply Shield with 3.3v, 5v and 12v Output Options in Sell/Buy electronics - Job offer/requests Posted May 20, 2020 When developing electronic projects, the power supply is one of the most important part of whole project and there is always need of multiple output voltage power supply. This is because different sensors need different input voltage and current to run efficiently. In this scenario, a power supply which can output multiple voltages becomes very important. There are options that an engineer can use for external power supply like RPS (regulated power supply) or AC adaptors but then multiple power supplies will be needed and the whole system will become bulky. So today we will be designing a Multipurpose Power Supply. The Power Supply will be an Arduino UNO Power Supply Shield which will output multiple voltage range such as 3.3V, 5V and 12V. The Shield will be a typical Arduino UNO shield with all pins of Arduino UNO can be used along with extra pins for 3.3V, 5V, 12V and GND. Here the PCB is designed on the EasyEDA PCB Designer and manufactured by PCBgogo. Components Required LM317 – 1 Unit LM7805 – 1 Unit LED(Any Color) – 1 Unit 12V DC Barrel Jack – Unit 220Ω Resistor – 1 Unit 560Ω Resistor – 2 Units 1uF Capacitor – 2 Units 0.1uF Capacitor – 1 Unit Burg Pins(20 mm) – 52 Units Circuit Diagram The circuit diagram and schematic for Arduino Power Supply Shield is pretty simple and doesn’t contain much component placement. We will be using 12V DC Barrel Jack for main voltage input for the whole Arduino UNO Shield. The LM7805 will convert 12V to 5V output, similarly the LM317 will convert 12V to 3.3V output. LM317 is popular Voltage regulator IC can be used to build variable voltage regulator circuit. Fabricating the PCB for Arduino Power Supply Shield After making the circuit ready, it’s the time to go ahead with designing our PCB using the PCB design software. As stated earlier we are using EasyEDA PCB Designer, so we just need to convert the schematic to a PCB Board. When you convert the schematic into board, you also need to place the components in the places according to the design. After converting the schematic above to board my PCB looked like below. Assembling the PCB After the board was ordered, it reached me after some days though courier in a neatly labelled well-packed box and like always the quality of the PCB was awesome. Get the soldering kit and start placing all the components in the right pads of the PCB Board. The soldering is easy to finish as there is not much components used in this project. When the soldering is finished your board should look like below. In this Power Shield the burg pins used is of male to male 20 mm connectors. You can use Male to Female Burg pins depending upon the availability. The 20mm burg pins are suitable for Arduino Shield and fits well for on Arduino UNO. Testing the Power Supply Arduino Shield It is really easy to test the Arduino shield. Just place the shield on to the Arduino UNO and give it a 12V supply from the input barrel jack. The shield can take input voltage of maximum up to 34V without damaging the components. You can check all the output voltage i.e. 3.3V, 5V and 12V using a digital multimeter. If all went good including designing and soldering of the components then you will be able to note down the exact output voltage at the output pins.