The appearance of the 300W color screen version of the host.

Over-the-air (OTA) firmware upgrade

Project Brief Introduction

This power supply is small and beautiful, with a built-in high-quality high-power AC-DC switching power supply module, which can not only provide a three-way fast charging source for notebooks, mobile phones and other electronic devices, but also has an independent DC output socket, which is convenient for DC soldering stations, CNC adjustable power supplies, DC heating stations and other tools to provide stable and reliable high-power DC power supplies, which are very widely used and worth having!

Let's take a look at the beautiful pictures of the prototype first, and then read on if you like it.

Project features

This machine has a built-in standard size small volume switching power supply module, and an independent DC output socket is set up, which can provide a stable DC power supply for other electronic equipment or tools.

This machine supports USB CCA three-way fast charging output, which can provide high-power multi-protocol fast charging function for notebooks, mobile phones and other electronic devices.

There are power indicators and two fast charging indicators, which are convenient to know their working status.

Open-source protocol

CC-BY-NC-SA 4.0

When reprinting, please indicate the original author and link.

Project properties

This project is the first public and is my original project. The project has not won an award in another competition.

Project parameters

The fast charging circuit of the motherboard uses two fast charging chips, SW3538 and SW3526 of ismartware.

SW3538S is a highly integrated multi-fast charging protocol dual-port charging chip, which supports the fast charging output of any port of A+C port and supports independent current limit of dual ports. It integrates a 7A high-efficiency synchronous step-down converter, supports PPS/ PD/ QC/ AFC/ FCP/ FCP/ SCP/ PE/SFCP/TFCP/VOOC and other fast charging protocols, supports a maximum output power of 140W, integrates CC/CV mode, dual-port management logic and other functions.

Design Principles

According to his own production experience, the author has partially optimized the official circuit on the basis of not affecting all the functions of SW3538, and only uses 2 MOS tubes to complete the two-way power output of SW3538 circuit, which not only greatly reduces the area required by the circuit board, but also has higher efficiency and lower temperature rise after actual measurement. Under the condition that the motherboard does not add any auxiliary heat dissipation, it can provide a stable 100W power output, which is excellent.

The motherboard adopts a 4-layer board design, and after repeated comparison and verification, the inductor uses a high-current magnetic ring wire wound inductor, so that it has sufficient space for heat dissipation. After many adjustments and optimizations in circuit design and device selection, the highest temperature rise in the current high-current output state is not the chip, MOS tube and inductor, but the finished power module, but because the aluminum chassis used has a certain auxiliary heat dissipation effect, so in actual use, the phenomenon of overheating protection of the power supply has not been found. If you need to work at high power for a long time, you can add a cooling fan according to the requirements of the power manual.

Since SW3538 and SW3526 are both step-down chips, the input voltage needs to be higher than the output voltage, and it is recommended to use a power module with an output voltage of DC 24V.

Circuit diagram of the whole machine

3D preview

Front layout

Physical outline drawing

The picture shows that the chassis uses the 8838x130mm aluminum profile chassis sold in the JLCFA mall, with excellent workmanship and good heat dissipation, and there are coupons every month, which is recommended to buy. The internal height of the 8838*130 shell of the same model purchased online will be slightly lower, and the power module needs to be installed from the bottom to the top, and the bottom metal shell should be insulated.

Internal wiring diagram

(The two prototypes are respectively installed with the same standard installation size of Zhongyiguang 150W and Jinshengyang 225W power modules, and the current open source version has optimized the layout and wiring again, which is more beautiful and reasonable)

140W output power test

SW3538 PDO packets

SW3536 PDO packets

Ripple simple test

Others：

• The attachment provides the 2.0 and 3.0 versions of this project, including circuit schematic diagrams, PCB board files, device procurement BOM and other materials, more information please add to the group to download.
• The author's self-designed panel and backboard files are also shared in the attachment.

 After the author's test and actual use of the basic parameters, the prototype has reached the design goal in all aspects, and the use effect is very good, not only supporting more fast charging protocols, but also more stable than the gallium nitride charging head when working at high current. It costs less than 100 yuan to reproduce such a beautiful high-power desktop fast charging source, not only with multiple fast charging functions, but also with a 150W 24V DC power output, and the most important thing is that you will have a sense of accomplishment when you see it! Isn't this more fragrant than spending one or two hundred to buy a charging head?

If you like the design of this project, please bookmark this article below and like it to encourage the author to contribute more and better works to you in the future. If there are many people who like it, the author will release some works with the desktop power supply in the future, if you are interested, in order to avoid getting lost, you can follow the author.