Project Hub /Basic Analog & Power Electronics/Power Supplies & Voltage Regulators/Variable Power Supply By Arduino Uno

Beginner

ARDUINO

₹500 – ₹1,500

3 – 6 Hours

Partial Kit

Variable Power Supply By Arduino Uno

Build a simple 5V variable voltage power supply source controlled by an Arduino Uno using ADC and PWM features.

Originally published on CircuitDigest

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

Arduino UNO R3 Board (Compatible) – ATmega328P Microcontroller with USB Cable Rs. 999.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
2-Slot 18650 Holder with Protective Cover and On/Off Switch – Case Rs. 109.00
10pcs - 220 ohm 1/4 W Resistor Set Rs. 39.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

This list includes a generic resistor set as a placeholder — it is not matched to the exact value or part number this circuit needs. The correct one is specified on the original source page linked above; check it before buying.

We don't carry yet: LCD (generic / unspecified)
Capacitors
Transistors (BC547 / 2N2222 / TIP / MOSFET)

Browse all components

How It Works

The Variable Power Supply project centers around an Arduino Uno acting as the core processing and control unit. The system utilizes the Arduino's built-in Analog-to-Digital Converter (ADC) to read user inputs from two push buttons, which are stabilized using 1KΩ resistors configured as pull-up or pull-down networks. When the user presses the buttons, the Arduino interprets these signals to adjust its Pulse Width Modulation (PWM) output. This PWM signal is sent to a 2N2222 transistor, which functions as a switching or amplifying element to regulate the power flow. To ensure stable operation, 100uF capacitors are included in the circuit to help filter out voltage ripples and smooth out the power delivery. Finally, a 16x2 character LCD is connected to the Arduino Uno to provide a real-time visual readout of the operational status and voltage settings, allowing the maker to monitor the adjustments as they are made.

Why Build This

Create a reliable 5V power source for testing custom sensor modules and low-voltage electronic circuits.

Gain hands-on experience in generating variable voltage outputs using basic maker components like transistors and microcontrollers.

Build a custom benchtop prototyping tool that can be used for small-scale educational experiments and battery charging tests.

Real-World Application

Powering sensor modules, testing electronic circuits with varying voltage requirements, charging small rechargeable batteries, and educational prototyping.

Skills You'll Learn

ADC input reading

PWM signal generation

transistor switching control

LCD character display interfacing

button debouncing and digital input handling

Safety Precautions

Ensure input voltages and components are properly rated when scaling to higher currents or voltages to prevent overheating or component failure.

Technology Tags

ARDUINO

PWM

ADC

LCD DISPLAY

TRANSISTOR

POWER SUPPLY

C++

EMBEDDED SYSTEMS

Frequently Asked Questions

Can I power high-current devices directly with this power supply?

No, the 2N2222 transistor and standard components are designed for low-current signal and hobbyist prototyping applications, not heavy-duty power delivery.

What software do I need to program the Arduino Uno?

You can use either the Arduino IDE or Atmel Studio 6.2 to write and upload the control code to your board.

What is the purpose of the 100uF capacitors in this circuit?

The 100uF capacitors are used to help filter and smooth out voltage fluctuations, ensuring a more stable power supply output.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

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