How to Build a Simple Arduino Voltage Regulator That Will Save You Money on Batteries


Building your own voltage regulator for Arduino projects can help you save money on batteries in the long run. In this comprehensive guide, I will walk you through the complete process of constructing a basic voltage regulator circuit using common electronic components.

Whether you are new to electronics and Arduino or have some experience, this project is fairly straightforward. By the end, you will have the satisfaction of powering your Arduino with a reliable, efficient power supply you created yourself for a fraction of the cost of a pre-made module.

Overview of Voltage Regulation

Before we get started building, let's go over some key concepts about voltage regulation and why it's important for powering devices like Arduino.

What Is Voltage Regulation?

Voltage regulation is the process of converting an unstable voltage to a steady, consistent output voltage. The incoming voltage from a power source often fluctuates. Voltage regulators smooth out these fluctuations to provide a predictable voltage for powering sensitive electronic components.

Why Do We Need Voltage Regulation for Arduino?

Arduino boards require a steady 5V power supply for reliable operation. However, power sources like batteries provide varying voltage as they drain. Without regulation, the fluctuating voltage can damage the Arduino or cause erratic behavior. A regulator maintains a steady 5V supply as the battery voltage declines.

Linear vs. Switching Regulators

There are two main types of voltage regulators:

For this simple project, we will build a basic linear regulator. Linear regulators are inexpensive and easy to construct for low current applications like Arduino projects.

Parts and Tools Needed

You don't need many components to build a basic Arduino voltage regulator. Here are the essential items:



The 7805 regulator is the heart of the circuit. It takes a 7-12V input and regulates it down to a steady 5V output. Make sure you have the required capacitors and diode as well.

Constructing the Circuit

With the components ready, it's time to build the voltage regulator circuit. Follow these steps to put it together:

1. Insert the 7805 Regulator

Place the 7805 regulator on the breadboard. The input pin is on the left, output pin on the right, and ground pin in the center.

2. Connect Input Capacitor

Insert the 10uF input capacitor. Connect it between the input pin and ground. This capacitor helps filter noise from the input power.

3. Connect Output Capacitor

Add the 0.1uF output capacitor. Connect it between the output pin and ground. This capacitor smooths out any ripples in the regulated output.

4. Add Protection Diode

Place the 1N4001 diode with the cathode (banded side) to the input and anode to output. This protects the regulator from reverse polarity damage.

5. Connect Input and Output

Use jumper wires to connect the input pin to your power source positive and output pin to Arduino 5V pin.

6. Connect Ground

Finally, link the regulator ground and Arduino GND. The circuit shares a common ground.

Here is the wiring diagram:

Check your connections against the diagram and ensure there are no shorts.

Testing the Voltage Regulator

Before connecting your Arduino, it's a good idea to test the regulator output. Follow these steps:

1. Power Up Without Arduino

Apply 7-12V power to the input but leave the Arduino disconnected.

2. Check Voltage Levels

Use a multimeter to measure the input voltage and output voltage. The output should read close to 5V.

3. Verify Regulator Operation

Vary the input voltage and confirm the output remains steady at around 5V. The regulator is working correctly if the output voltage stays constant as the input changes.

4. Connect LED and Resistor

For a simple functionality check, connect an LED and resistor between the regulator output and ground. The LED should light up, indicating 5V at the output.

If the regulator maintains a solid 5V out during your tests, it's ready to power an Arduino!

Using the Voltage Regulator

With the regulator circuit built and tested, here is how to use it to power an Arduino:

1. Connect Arduino 5V Pin

Disconnect your test setup and use jumper wires to connect the regulator output to the Arduino board's 5V pin.

2. Connect Arduino Ground

Also connect the regulator ground to the Arduino GND pin.

3. Supply 7-12V Input Power

Apply 7-12V DC input power to the regulator. This can come from batteries, a wall adapter, or other power supply.

4. Upload a Sketch

With the Arduino now powered through the regulator, you can upload a sketch and begin prototyping!

5. Disconnect Batteries When Not In Use

Make sure to disconnect your batteries when not using the Arduino to avoid draining them. The regulator only converts voltage when the input power is active.

That's it! Your Arduino now has a steady 5V supply from the 7805 voltage regulator you built.

Troubleshooting Tips

Here are some common problems and solutions if your regulator circuit isn't working:

Carefully inspecting all breadboard connections and wiring is key for troubleshooting. Check the regulator datasheet for additional guidance.

Saving Money on Batteries

Building your own Arduino regulator helps reduce battery costs in a few ways:

Having a reliable power supply you constructed yourself is also very satisfying!


Constructing a simple linear voltage regulator for Arduino is an easy, educational electronics project. A regulator maintains the steady 5V required to power an Arduino as the batteries drain. By building your own regulator circuit, you can save money on batteries for Arduino projects.

This guide covered key concepts like the importance of regulation and the difference between linear and switching types. We went through a complete step-by-step build process using common components. Testing procedures were provided to verify correct operation before connecting to Arduino. Finally, we looked at troubleshooting tips and how the regulator helps reduce battery costs.

The skills you learn creating your own regulator circuit will help as you advance in electronics and take on more complex Arduino projects. I hope this article provided everything you need to build a voltage regulator that saves you money on batteries for powering your future Arduinos! Let me know if you have any other questions.