In recent years, the DIY electronics community has undergone a dramatic transformation, driven largely by the proliferation of open-source hardware and software. Among the most significant developments is the rise of open-source power supply designs. These publicly available schematics, PCB layouts, and firmware files empower hobbyists, students, and professionals to build reliable, customizable, and cost-effective power solutions for a vast range of projects. The movement fosters collaboration, accelerates innovation, and democratizes access to advanced electronics, making it easier than ever to fabricate complex systems in home workshops or small labs. This article explores what open-source power supplies are, why they matter, notable projects, and how you can get started.

What Are Open-Source Power Supplies?

An open-source power supply is a complete design for a voltage or current regulator circuit—including schematics, bill of materials, board layouts, and often microcontroller firmware—that is released under an open-source license such as the GPL, MIT, or CERN Open Hardware License. Unlike proprietary power supply products, open-source designs are freely available for anyone to use, modify, and redistribute. This transparency allows users to understand every aspect of the power supply’s operation, from component choices to control algorithms.

Open-source power supplies come in many forms:

  • Linear power supplies – Known for low noise and simplicity, often using adjustable regulators like the LM317 or LM338.
  • Switching power supplies (SMPS) – More efficient and compact, but require careful design of inductors, transformers, and feedback loops.
  • Bench power supplies – Programmable units with digital displays, constant voltage/constant current (CV/CC) operation, and sometimes remote control via USB or Bluetooth.
  • USB power supplies – Dedicated 5 V outputs for charging and powering microcontroller boards, sensors, and peripherals.
  • Battery chargers – Intelligent circuits for lithium-ion, lead-acid, or NiMH cells with open-source firmware for charging algorithms.

The openness extends beyond hardware: many projects include firmware written in C or MicroPython that can be modified to add features like data logging, over-temperature protection, or integration with IoT platforms.

Advantages of Open-Source Designs

The popularity of open-source power supplies is not accidental. The benefits appeal to both beginners and seasoned engineers.

Cost-Effectiveness

Most open-source designs rely on widely available, off-the-shelf components such as the LM338, XL4016, or TPS54331. By sourcing parts from distributors like Mouser, DigiKey, or AliExpress, builders can assemble a capable bench supply for a fraction of the cost of commercial equivalents. Moreover, the design files are free, eliminating expensive licensing fees or development costs.

Customizability

Users can modify circuits to meet specific voltage and current ranges, add extra filtering, incorporate multiple outputs, or change form factors. For example, a hobbyist needing a ±15 V supply for audio op-amps can derive the symmetric topology from a single-ended open-source design. Firmware can be tweaked to implement soft-start, ripple cancellation, or battery charging profiles.

Community Support and Collaboration

Open-source projects thrive on community contributions. Forums, GitHub repositories, and dedicated websites offer a wealth of troubleshooting advice, design improvements, and shared experiences. When a user encounters an issue—like oscillation at high currents or poor transient response—someone else has likely solved it. This collective intelligence accelerates learning and reduces frustration. Popular platforms include Hackaday.io, GitHub, and EEVblog forums.

Transparency and Safety

Complete schematics and firmware allow users to verify safety features, understand failure modes, and adopt best practices. In a commercial power supply, the internal design is often a black box; if something fails, repair is difficult. With open-source, users can trace the circuit, replace components, and even improve protection circuits. For high-power designs, transparency is crucial for ensuring proper thermal management and isolation.

Educational Value

Building an open-source power supply teaches fundamental concepts such as voltage regulation, feedback loops, heat sinking, PCB layout, and firmware development. It bridges theoretical knowledge from textbooks with hands-on soldering and debugging—skills that are essential for any electronics enthusiast.

Several projects have garnered large followings and are considered benchmarks in the community.

Open Power Supply (OPS) – The LM338 Classic

One of the earliest and most widely cloned designs, the Open Power Supply uses the LM338 adjustable regulator to provide 1.2 V to 30 V at up to 5 A. It includes constant current limiting, an analog meter, and a robust heatsink design. The simplicity makes it an ideal first build for learning linear regulation. The design is available on GitHub with comprehensive assembly instructions.

DIY USB Power Supply

A compact design based on the LM2596 or similar buck converter that delivers a stable 5 V output from a variety of input sources (6–30 V DC). Many variants include USB A connectors, overcurrent protection, and a small OLED display showing voltage and current. This project is perfect for powering Arduino or Raspberry Pi projects on the go.

Open Source Lab Power Supply (OSLPS)

The OSLPS is a high-current (up to 10 A), programmable bench supply with dual outputs, CC/CV modes, and a built-in microcontroller offering remote control over USB. Its firmware, written in C, can be recompiled to add features like data logging to a PC. The design files are on GitHub and the project has spawned many derivative versions with different voltage ranges.

Riden RD6006 – Digital Power Supply with Open-Source Roots

While the Riden RD6006 is available as a commercial module, its firmware and protocol are open source, allowing extensive customization. This is a 60 V, 6 A programmable DC-DC converter with a color screen, rotary encoder, and USB/serial control. Hobbyists have reverse-engineered the command set and created custom Python scripts for automated testing or battery charging. The EEVblog thread contains extensive mods and community support.

DPS Series by DROK

The DPS series (e.g., DPS5005, DPS5020) are high-power buck converter modules that support CV/CC modes and can be controlled via I2C. Though not fully open hardware, their open communication protocol and popularity have led to many third-party front-end boards, case designs, and firmware forks that create fully open-source bench supplies.

Impact on the DIY Community

The availability of open-source power supply designs has fundamentally democratized electronics development. Previously, building a reliable programmable bench supply required deep expertise and costly components. Today, a hobbyist with basic soldering skills can assemble a 30 V, 5 A supply for under $50. This accessibility has several profound effects:

  • Lowered barrier to entry – Students and makers can experiment with power electronics without significant financial risk, encouraging more people to pursue STEM careers.
  • Accelerated innovation – When designs are open, incremental improvements spread quickly. A new heat-sink arrangement or better filter design in one project can be integrated into dozens of others within weeks.
  • Education and knowledge transfer – Open schematics serve as real-world learning material. Universities and online courses now use these designs as lab exercises for courses on power electronics and embedded systems.
  • Commercial spin-offs – Several small businesses have emerged selling kits, pre-assembled boards, or enclosures based on open-source power supply projects. This demonstrates that open-source can sustain commercial ecosystems while keeping the core design free.

The community also benefits from the transparency of safety features. With open designs, users can simulate or analyze the circuit to ensure it meets their specific safety requirements—something not possible with proprietary equipment. This has led to higher overall design quality as manufacturers incorporate community feedback into revisions.

Getting Started with Open-Source Power Supplies

If you are ready to dive in, follow these practical steps to build your first open-source power supply.

1. Define Your Requirements

Determine the voltage and current range you need. A general-purpose bench supply often ranges from 0–30 V and 0–5 A. If you work mainly with digital logic, a 5 V / 3 A USB supply might suffice. For battery charging, consider designs with programmable current limits and termination algorithms.

2. Choose a Project

Browse repositories on Hackaday.io or GitHub using keywords like “open source bench power supply” or “DIY lab supply.” Look for designs that have good documentation, a bill of materials with distributor links, and an active community. The Open Source Lab Power Supply and DIY USB Power Supply are excellent starting points.

3. Gather Tools and Components

Essential tools: soldering station with adjustable temperature, multimeter (preferably with capacitance and frequency measurement), oscilloscope (helpful but not mandatory for simpler linear designs), and PCB etching or ordering service (e.g., JLCPCB). Many projects include Gerber files that you can submit directly to a board house. Purchase components from reputable distributors to avoid counterfeit parts, especially for power transistors and ICs.

4. Assemble and Test

Start with the power supply’s low-voltage section (control electronics) before connecting high-power circuits. Use a dummy load (e.g., a high-wattage resistor) to test the output under load. Check for ripple and noise with an oscilloscope. Refer to the project’s troubleshooting guide for common issues like oscillations due to poor layout.

5. Contribute Back

Once your supply is working, consider sharing your build photos, modifications, or bug fixes on the project’s forum or repository. Even minor improvements—like adding a fuse holder or labeling connectors—help others. Open source thrives on contributions, no matter how small.

Future Outlook

The trend toward open-source power supplies is accelerating. With the rise of digital control and cheap microcontrollers, we are seeing hybrid designs that combine analog regulation with firmware-defined features like over-the-air updates, data logging, and Wi-Fi connectivity. Projects like the DPPM (Digital Power Panel Meter) and SmartPower aim to create fully open-source, IoT-enabled lab supplies. As the ecosystem matures, expect even higher integration, lower costs, and stronger safety certifications—all while keeping the design files public and modifiable.

Whether you are a beginner building your first bench supply or an experienced engineer creating a production-ready module, the open-source movement offers a wealth of resources. By adopting these designs, you not only save time and money but also join a global community dedicated to making powerful electronic tools accessible to all.