saIDcCoBfs

USB 2.0 expansion dock based on SL2.1A

Overview

Update Log:
2024.3.7 -- Project Creation
2024.7.6 -- Modification Notes
Preface:
1. Average cost per docking station as low as 2 RMB
2. Maximum speed up to 24MB/s
3. All resistors and capacitors use surface mount 0603 packages (those with poor soldering skills can change to other packages)
Physical Display
Front:

Back:

Actual Performance Test:
The test involved connecting a wired mouse and a USB flash drive

. It can be seen that except for a slow initial period, the transfer speed remained around 24MB/s.
Notes
Here are some basic mistakes I made, hoping everyone can learn from them:
1. The DIN+ and DIN- network labels were reversed when drawing the schematic. The problem was that the computer displayed a warning: "Unrecognized USB device. The previous USB device connected to this computer is not working properly. Windows cannot recognize it."
2. An error in drawing the schematic caused the bypass capacitor between VCC and GND to disconnect the power supply line to VCC, resulting in no power supply to the chip. Those with a multimeter can check this. If you don't have a multimeter, and your mouse has a built-in light, you can check if it's glowing...
3. The D+ and D- data lines are a pair of differential signal lines, which can be drawn using the differential lines provided with LCSC EDA.
If you absolutely cannot draw differential lines in one step, you can first draw differential lines of unequal length, and then use the equal length adjustment function of LCSC EDA.

The green box shows the use of this function.

PDF_USB2.0 Expansion Dock Based on SL2.1A.zip

Altium_USB2.0 Dock Based on SL2.1A.zip

PADS_USB2.0 Dock Based on SL2.1A.zip

BOM_USB2.0 Dock Based on SL2.1A.xlsx

93892

ch224k Simple trick to lure 9v, 12v

Using CH224K to trick 9V and 12V power supplies

I previously made a bunch of LED lights that required a 12V power supply. Buying a 12V power supply online was quite expensive, and considering the various 12V requirements, I decided to experiment with creating my own 12V power supply.
I went through three versions based on different ideas, and actually, the first version was successful.
For instructions on the CH224K, please refer to the official documentation. The following points require special attention:
1. An LED was added to indicate the power-on status using VDD current; it's unclear if this is actually a problem.
2. The official documentation states that different resistors can induce different voltages, supporting 9, 12, 15, and 20V, but not 5V. The 20V design is quite unusual and counterintuitive. Therefore, a non-resistive MCU control mode was used to generate 5V using VDD current.
3. The inexpensive charger I bought only supports 66W and cannot induce voltages above 12V. Therefore, a higher-power charger is needed for 15V and 20V.
4. Inducing 5V, 9V, and 12V was successful.
5. A toggle switch was used. This component is somewhat expensive. Due to the CH224K's own design, if no toggle is used and the charger supports it, it defaults to inducing 20V (12V on my charger). If all toggle switches are used, it defaults to 5V.
6. This small module verified that my car charger actually supports PD output fast charging, but my phone is restricted, so it can't fast charge.

Theoretically, this small PCB should also have a DC converter, but the accessories are too expensive, so I cried. Later, I changed it to a 2P connector. A side

note: using solder paste on a Type-C connector by hand is too easy to cause sticking, wasting a board.

WeChat Image Editing_20240706111703.jpg

PDF_ch224k Simple Deception 9v, 12v.zip

Altium_ch224k Simple Deception 9v, 12v.zip

PADS_ch224k Simple Deception 9v, 12v.zip

BOM_ch224k Simple Deception 9v, 12v.xlsx

93893

GB game 32KB dual-head flashcart

GB game card 32KB no MBC required, can burn 32KB small games.

GitHub - LovelyA72/GB-Flash-Cart-32K: Easy to build open source 32KB Gameboy Flash cart Flashcart KiCAD Schematic and PCB File
https://www.bilibili.com/video/BV1GS411A7Wc/?spm_id_from=333.999.0.0&vd_source=e3522c24494f1912b21e6ce2c7f03ae2

PDF_GB Game 32KB Dual-Head Flashcart.zip

Altium_GB Game 32KB Dual-Head Flashcart.zip

PADS_GB Game 32KB Dual-Head Flashcart.zip

BOM_GB Games 32KB Dual-Head Flashcart.xlsx

93895

Light Hammer 200 Battery Protection Board

Battery protection board for the Light Hammer 200 flashlight

Introduction and production process of a 1.0mm thick
flashlight: The old man upstairs thought it was dawn. 200 yuan handmade 200 watt 27000 lumen flashlight_Bilibili_bilibili
Battery pack making tutorial: [Open source] 200 watt 30000 lumen flashlight light hammer 200 replica tutorial 1: Battery pack_Bilibili_bilibili
Light hammer 200 replica exchange group: 522608529 You can ask me questions in there if you encounter problems during the replica process.

eve25p_final.srec

Battery spot welding mold.stl

PDF_Light Hammer 200 Battery Protection Board.zip

Altium_Light Hammer 200 Battery Protection Board.zip

PADS_Light Hammer 200 Battery Protection Board.zip

BOM_Light Hammer 200 Battery Protection Board.xlsx

93896

EastMartrix Pixel Clock Master

Modified based on the open-source code of Da Congming on Bilibili.

The surface-mount resistor was changed to a 0603 package, and the photoresistor was directly soldered onto the PCB.
This controls the EastMartrix pixel screen display.

PDF_EastMartrix Pixel Clock Master Controller.zip

Altium_EastMartrix Pixel Clock Master Controller.zip

PADS_EastMartrix Pixel Clock Master Controller.zip

BOM_EastMartrix Pixel Clock Master Controller.xlsx

93897

Industrial control board PLC_V1.1

A PLC industrial control board, compatible with Mitsubishi FX2N, which can use ladder diagrams written by Mitsubishi.

The main controller is an STM32F103VET6, which has been verified to work properly after flashing custom firmware. It needs to be programmed using a flashing socket. The wiring is only connected and hasn't been optimized yet; I'll optimize it later when I have time.

PDF_Industrial Control Board PLC_V1.1.zip

Altium_Industrial Control Board PLC_V1.1.zip

PADS_Industrial Control Board PLC_V1.1.zip

BOM_Industrial Control Board PLC_V1.1.xlsx

93898

15-24V input, ±35V output power supply based on TPS40210

The SEPIC+CUK circuit based on TPS40210 can realize the step-up and step-down of positive and negative voltages and can be used as the positive and negative power supply for power amplifiers.

Circuit principles, design considerations, and software tools are explained in reference to Professor Tang's related videos: Op-amp Dual Power Supply, Open Source XL6007 SEPIC+CUK Schematic and PCB.

Test results and modification suggestions are provided directly here.
The TPS40210 is an asynchronous boost controller; appropriate switching transistors can be selected to increase output power.
The switching frequency is set to 550kHz, achieving ±35V output.

The physical diagram is shown below.

The testing method is as follows:

15V and 20V voltages were taken from the power adapter using a CH224K for testing.
The load is a BTL power amplifier circuit built with a TDA7294V.
The filter capacitor on the power amplifier board was not soldered because soldering it would cause abnormal power output. The reason is estimated to be that the output capacitor is too large, resulting in excessive current during power-on and triggering the chip's protection function (the load current is designed for 2A).

The actual output power is unclear. There was no resistor as a load, and the output volume was not turned up too high to avoid disturbing neighbors. Ripple was measured at the following four locations.

Significant differences were encountered during positive voltage measurements.
The result measured on the power board was unusual, reaching 72mV.

On the amplifier board, the ripple measured from the large capacitor pad was only around 18mV.

The negative voltage was more normal:
approximately 13mV on the power board and

approximately 20mV on the amplifier board.

Furthermore, the inductor temperature was high during operation; a larger package could be considered.

When modifying the wiring layout, care should be taken to minimize the area of the two high-frequency current loops.

PDF_Power Supply Based on TPS40210: 15-24V Input, ±35V Output.zip

Altium_TPS40210-based 15-24V input, ±35V output power supply.zip

PADS_TPS40210-based 15-24V input, ±35V output power supply.zip

BOM_Power Supply Based on TPS40210 15-24V Input, ±35V Output.xlsx

93900

TA7642 AM Receiver

Simple TA7642 AM radio powered by 1.5V

PDF_TA7642 AM Receiver.zip

Altium_TA7642 AM Receiver.zip

PADS_TA7642 AM Receiver.zip

BOM_TA7642 AM Receiver.xlsx

93903

electronic

Design Files

All reference designs on this site are sourced from major semiconductor manufacturers or collected online for learning and research. The copyright belongs to the semiconductor manufacturer or the original author. If you believe that the reference design of this site infringes upon your relevant rights and interests, please send us a rights notice. As a neutral platform service provider, we will take measures to delete the relevant content in accordance with relevant laws after receiving the relevant notice from the rights holder. Please send relevant notifications to email: bbs_service@eeworld.com.cn.

It is your responsibility to test the circuit yourself and determine its suitability for you. EEWorld will not be liable for direct, indirect, special, incidental, consequential or punitive damages arising from any cause or anything connected to any reference design used.

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Update:2026-03-26 19:29:48

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