4 DIY Power Electronics Projects You Should Build – SG3525 Inverters & NCP1653 PFC Circuits

For the past few years, I've been designing and building power electronics circuits as both a hobby and a learning experience. In this project, I'd like to share four of my favorite designs that have been thoroughly tested and successfully operated.

The collection includes two inverter designs based on the SG3525 controller and two Power Factor Correction (PFC) circuits based on the NCP1653. Together, they cover everything from a compact portable inverter to a high-power 2.5 kilowatt PFC converter.

All of the PCB boards shown in this project were manufactured by JLCPCB.

Components

1. PCB boards
2. SG3525 PWM controller
3. NCP1653 PFC controller
4. IRF3205 or IRFZ44 MOSFETs
5. Ferrite transformers
6. Ferrite cores for custom inductors
7. Electrolytic capacitors
8. Fast recovery diodes
9. Power resistors
10. Connectors and terminal blocks
11. Miscellaneous resistors and capacitors

Tools

1. Soldering station
2. Digital multimeter
3. Oscilloscope
4. Adjustable DC power supply
5. Electronic load (optional)
6. Screwdrivers
7. Wire cutters
8. Solder wire
9. Flux

PCB Files

1. Gerber files all file here

The second project is a 2.5 kilowatt inverter using two transformers for higher output power.

2.5 kilowatt Inverter using two transformers, featuring soft start/soft shutdown, input overvoltage and undervoltage protection, and over-temperature protection. https://youtu.be/5jBU-Qym6rI?si=FU2wY7mgjQC_HeRG

The circuit is also based on the SG3525 controller but includes many protection features normally found in commercial products.

Features

1. Soft start / soft shutdown
2. Input overvoltage protection
3. Input undervoltage protection
4. Over-temperature protection
5. Dual-transformer design
6. H-Bridge PWM output stage

Thanks to the dual-transformer architecture, the inverter can drive demanding loads such as:

1. Fans
2. Electric motors
3. Power tools
4. Household appliances

while maintaining stable output performance.

The first project is a compact 100 watt mini inverter based on the SG3525 PWM controller.

100 watt Mini Inverter (12 volt DC to 220 volt AC) based on the SG3525 controller. https://youtu.be/BUm8OjSv6gU?si=xw4JN8I7jk_cvEp7

Features

1. Input: 12 volt DC
2. Output: 220 volt AC
3. Adjustable output voltage
4. Switching frequency: 34 kilohertz
5. MOSFETs: IRF3205 or IRFZ44
6. Compact PCB
7. Easy to build

Although small, this inverter is capable of powering:

1. Phone chargers
2. LED lighting
3. Small electronic devices
4. Portable equipment

Its simple design makes it an excellent project for beginners who want to learn inverter design.

The final project is a high-power 2.5 kilowatt PFC converter.

This design is also based on the NCP1653, but uses a totem-pole MOSFET driver to achieve much higher output power.

2.5 kilowatt PFC Boost Converter using the NCP1653 with a totem-pole MOSFET driver for high efficiency and high output power. https://youtu.be/sIVP9Rl0CZU?si=bvysZCHyQeg9GJdM

Features

1. Output power up to 2.5 kilowatts
2. 15–24 volt auxiliary power supply
3. Dedicated control power board
4. High-efficiency custom inductors
5. Excellent regulation
6. High reliability

To handle the higher power, two ferrite cores are stacked together to build the custom boost inductor, allowing the converter to operate efficiently while delivering its full rated power.

The third project is a 700 watt Power Factor Correction (PFC) circuit using the NCP1653 controller.

The circuit accepts an AC input from:

85 volt AC to 250 volt AC

and produces a regulated:

380 volt DC

output.

700 watt PFC Boost Converter based on the NCP1653, operating from 85 to 250 volt AC with a stable high-voltage DC output. https://youtu.be/Ixpg7F2atSc?si=B7U-TReAjal706gi

Advantages

1. High power factor
2. Stable output voltage
3. Improved power supply efficiency
4. Easy-to-find components
5. Built-in 15 volt power supply
6. Custom-wound inductor

This project is ideal for learning how active PFC works in modern switch-mode power supplies.

All of the PCB boards shown in this project were manufactured by JLCPCB.

After uploading my Gerber files, the boards arrived in about one week. The PCB quality was excellent, with accurate drilling, clean solder masks, and high-quality silkscreen printing.

I've shared the Gerber files, so you can order the same PCB boards and build these projects yourself.

These four projects cover a wide range of power electronics topics—from a simple 100 watt mini inverter to a 2.5 kilowatt inverter and two high-performance PFC converters.

I hope these designs help you learn more about inverter technology, active PFC circuits, PCB design, and high-power electronics.

If you decide to build one of these projects, I'd love to hear about your results. Feel free to leave a comment, share your experience, or suggest ideas for future projects.

Thank you for reading, and happy building!