On August 25th,
the circuit was updated and fine-tuned, so that the distortion is close to 0 (the 20khz sine wave is only 0.001%, and the no-load is 0.000%) .
The board is already on the way, and it will be soldered in two days
. I have to wait for another one.
————————————————Split line————————————————
Use dual package transistor differential input stage and Darlington tube voltage amplification stage, Dual NMOS outputs can achieve extremely low distortion without matching components. The measured thd is only 0.005%. The output power is high and the listening experience is good.
The measured data of no-load rmaa is consistent with the multisim simulation, thd0.005%! When tested with a 4 ohm speaker, there was only a slight drop.
I found a sound card that cost more than 100 yuan and re-tested
the power amplifier. There is no potentiometer. I lowered the volume on my mobile phone and measured the sound source. The actual indicators will be better.
The square wave test showed no overshoot.
The chip components are on the front and the plug-ins are on the back. The distance between the two mos tubes is 25mm (there is a "TDA2030 heat sink 70*15*50mm" on the tb that can be adapted)
BOM download
PCB_PCB_Open Source Differential Input 1969m Power Amplifier_2022-09-23.pdf
PCB_PCB_Open Source Differential Input 1969m Power Amplifier_2022-09-23.json
PCB_Open Source Differential Input 1969m Power Amplifier_2022-09-23.pcbdoc
Gerber_PCB_Open source differential input 1969m power amplifier.zip
Schematic_Open Source Differential Input 1969m Power Amplifier_2022-09-23.pdf
SCH_Open Source Differential Input 1969m Power Amplifier_2022-09-23.json
Sheet_1_2022-09-23.schdoc
61642
Thermostatic harmonica heating plate
Introduction: Heating plate suitable for Suzuki chromatic harmonica holes
The constant temperature heating function is realized through the thermistor, delay comparator circuit and mos. The heating power of 5v power supply is about 7-8w, and the heating will automatically stop when it reaches about 60 degrees. When
using typec or other plugs for power supply,
you can use silicone glue to seal the components to improve safety (actually it is not necessary, even if there is a short circuit with a regular charger, nothing will happen).
The best thickness for the board is 1.0mm, which can be put down just right typec port, if you don’t use typec interface, 0.8mm is also available, which is more convenient to cut.
BOM download
PCB_NTC-lm321 temperature control_2022-09-23.pdf
PCB_NTC-lm321 temperature control_2022-09-23.json
NTC-lm321 temperature control_2022-09-23.pcbdoc
Gerber_NTC-lm321 temperature control_2022-09-23.zip
Schematic_Constant temperature harmonica heating plate_2022-09-23.pdf
SCH_Constant temperature harmonica heating plate_2022-09-23.json
Sheet_1 copy_2022-09-23.schdoc
61643
Multi-signal generator composed of LM324 and 74LS00
Introduction: This is the self-assessment training of the 19th Guangzhou Institute of Navigation Electronic Information for the 2019 electronic competition retest questions. Review the use of operational amplifiers, RC circuits, NAND gates, etc. from this project, which is very comprehensive.
This is the practical training of the 19th session of Electronic Information of Guangzhou University of Navigation based on the retest questions of the 2019 electronic competition. Review the use of operational amplifiers, RC circuits, NAND gates, etc. from this project, which is very comprehensive.
Multiple signal generator design.ms14
BOM download
PCB_PCB_Multiple Signal Generator_2_2022-09-23.pdf
PCB_PCB_Multiple Signal Generator_2_2022-09-23.json
PCB_Multiple Signal Generator_2_2022-09-23.pcbdoc
Gerber_PCB_Multiple signal generator_2.zip
Schematic_Multi-signal generator composed of LM324 and 74LS00_2022-09-23.pdf
SCH_Multi-signal generator composed of LM324 and 74LS00_2022-09-23.json
Sheet_1_2022-09-23.schdoc
61644
Homemade GameBoy game console
Introduction: This project is based on esplay, and some components and circuits have been modified based on the original author's work.
1. This project is based on esplay. Some components and circuits have been modified based on the original author's work, and the pcb has been redrawn.
esplay project address: https://github.com/pebri86/esplay-retro-emulation
2. The production process can be seen here Video https://www.bilibili.com/video/BV1FL41157vK
3. Precautions
① IO0 and IO2 of ESP32 should be short-circuited, which can be done with a piece of tin
② A 3 mm thick spacer should be added between the PCB and the upper acrylic cover. 2 pieces of 2 mm acrylic spacers and then polish off 1 mm. You can also use stainless steel spacers to make up to 3 mm.
③ The 6 buttons up, down, left, right, A, and B need to be added with a 1.6 mm thick PCB pad.
④The screws used are 4 M2.5*5, 4 M2.5*10 and the studs are 4 M2.5*10.
4. The finished product rendering
uses 2 mm acrylic for the shell and is fixed with M2.5 screws
5. Firmware burning address
6. TF card directory structure
Game archives need to add a data folder in the esplay directory, which contains folders with simulator names such as nes, gbc, etc.
bootloader.zip
skeleton.zip
BOM download
PCB_Button spacer_2022-09-23.pdf
PCB_Button spacer_2022-09-23.json
Button gasket_2022-09-23.pcbdoc
Gerber_Button spacer_2022-09-23.zip
PCB_PCB_2022-09-23.pdf
PCB_PCB_2022-09-23.json
PCB_2022-09-23.pcbdoc
Gerber_PCB.zip
PCB_Acrylic shell_2022-09-23.pdf
PCB_Acrylic shell_2022-09-23.json
Acrylic shell_2022-09-23.pcbdoc
Gerber_Acrylic shell_2022-09-23.zip
Schematic_Homemade GameBoy Game Console_2022-09-23.pdf
SCH_Homemade GameBoy Game Console_2022-09-23.json
Sheet_1_2022-09-23.schdoc
61645
Homemade astronaut-themed thermometer and hygrometer
Introduction: This project uses ESP32 master control and SHT31 temperature and humidity sensor.
The project introduction uses ESP32 as the main control, the sensor uses SHT31, the screen is 2.4-inch ili9341, the UI is written using lvgl, and the collected data can be uploaded through a custom protocol in json format based on TCP. The demo video https://www.bilibili.com/video/BV1mr4y1x7e1 code is in my Github repository, including the firmware code of ESP32, and the IoT cloud platform code of a custom protocol implemented by myself https://github.com/ hsinyuwang/PicoIdeal Temperature and humidity numbers in large fonts are the first two decimal places, and in small fonts are the two decimal places. Actual renderings
BOM download
PCB_Shell_2022-09-23.pdf
PCB_Shell_2022-09-23.json
Shell_2022-09-23.pcbdoc
Gerber_Shell_2022-09-23.zip
PCB_PCB_PicoIdeal_2022-09-23.pdf
PCB_PCB_PicoIdeal_2022-09-23.json
PCB_PicoIdeal_2022-09-23.pcbdoc
Gerber_PCB_PicoIdeal.zip
Schematic_Homemade astronaut theme thermometer and hygrometer_2022-09-23.pdf
SCH_Homemade astronaut theme thermometer and hygrometer_2022-09-23.json
Sheet_1_2022-09-23.schdoc
61646
Homemade linux small computer
Introduction: Allwinner V3S main control, board shape and screw holes compatible with Raspberry Pi
Introduction
The main control adopts Allwinner V3S, single-core Cortex-A7, 64MB memory
board with rj45 network port, headset, microphone, TF card slot, USB, 40pin RGB screen interface
4.3-inch 800x480 resolution screen
casing is acrylic (see design drawing Shell, the DXF file can be exported and can be customized and cut in a certain treasure), M2.5 screw fixing
demonstration video
https://www.bilibili.com/video/BV19r4y1M7cf
physical picture
BOM download
PCB_Shell_2022-09-23.pdf
PCB_Shell_2022-09-23.json
Shell_2022-09-23.pcbdoc
Gerber_Shell_2022-09-23.zip
PCB_PCB_Allwinner_V3s_2022-09-23.pdf
PCB_PCB_Allwinner_V3s_2022-09-23.json
PCB_Allwinner_V3s_2022-09-23.pcbdoc
Gerber_PCB_Allwinner_V3s.zip
Schematic_Homemade linux small computer_2022-09-23.pdf
SCH_Homemade linux small computer_2022-09-23.json
Sheet_1_2022-09-23.schdoc
61647
TPA6120 Portable Headphone Amplifier V3.0
Introduction: A portable headphone amplifier powered by USB
Version update history:
V1.0-->First version, only includes the 6120 headphone amplifier and power supply (serious problems exist)
V1.1-->Added 2706 USB interface, 1754DAC, and audio source switching circuit (still has serious problems, this The plan has been scrapped)
V3.0 (pre-release) --> Cut off the low-performance USB decoding part, optimize the circuit design, and reduce the size. It is currently being produced. I hope it will not overturn.
Introduction
This is a USB-powered Desktop headphone amp, compact in size, easy to carry and store. The headphone amplifier chip is TPA6120A2, the input buffer operational amplifier is NJM4580,
the TPS65131 is used to generate positive and negative 12V power supplies, and an 8-pin potentiometer is used for switching on and off and adjusting the volume, which can drive headphones with an impedance of 16Ω~600Ω.
V3.0 PCB design drawing, the PCB size is reduced from the previous generation’s 80*50 to 60*40 (the extra 1.6mm on each side is used to fit into the 60*19*46 casing. The
matching front and rear panels are currently being designed Center)
3D simulation diagram:
physical display part
(to be added)
BOM download
PCB_PCB_TPA6120 Portable Headphone Amplifier V3.0_2022-09-23.pdf
PCB_PCB_TPA6120 Portable Headphone Amplifier V3.0_2022-09-23.json
PCB_TPA6120 Portable Headphone Amplifier V3.0_2022-09-23.pcbdoc
Gerber_PCB_TPA6120 Portable Headphone Amplifier V3.0.zip
PCB_Potentiometer Daughter Board_2022-09-23.pdf
PCB_Potentiometer daughter board_2022-09-23.json
Potentiometer daughter board_2022-09-23.pcbdoc
Gerber_potentiometer daughter board_2022-09-23.zip
PCB_Rear Panel V3.0_2022-09-23.pdf
PCB_Rear Panel V3.0_2022-09-23.json
Rear panel V3.0_2022-09-23.pcbdoc
Gerber_Rear Panel V3.0_2022-09-23.zip
PCB_Front Panel V3.0_2022-09-23.pdf
PCB_Front Panel V3.0_2022-09-23.json
Front panel V3.0_2022-09-23.pcbdoc
Gerber_Front Panel V3.0_2022-09-23.zip
PCB_PCB_TPA6120 Portable Headphone Amplifier (Abolition)_2022-09-23.pdf
PCB_PCB_TPA6120 Portable Headphone Amplifier (Abolition)_2022-09-23.json
PCB_TPA6120 Portable Headphone Amplifier (Abolition)_2022-09-23.pcbdoc
Gerber_PCB_TPA6120 Portable Headphone Amplifier (Abandoned Case).zip
Schematic_TPA6120 Portable Headphone Amplifier V3.0_2022-09-23.pdf
SCH_TPA6120 Portable Headphone Amplifier V3.0_2022-09-23.json
TPA6120 Portable Headphone Amplifier V3.0_2022-09-23.zip
61648
CH9340 USB to serial port module
Introduction: USB to serial port module based on CH9340K
The mini version of the CH9340 USB to serial port module uses CH9340K as the conversion chip, without the need for an external crystal oscillator or driver.
The TYPE-C port is connected to the computer, and the 5-pin header leads to the +5V power supply, UART serial port (RXD/TXD), and ground (GND). The wiring sequence is as follows:
onboard RX/TX indicator light. When sending data, the red LED flashes; receiving When data is being read, the green LED flashes
onboard 0.5A self-recovery insurance. The original design used an ESD array as electrostatic protection, but it was removed from the PCB due to size restrictions: (
The PCB size is 14mm*22mm, which is better than the online solution using this chip. It should be smaller.
Because this chip uses the system’s own CDC driver, many functions cannot be used normally, but it is no problem to download the program to the microcontroller. If necessary, it is recommended to change to CH340K, VCP driver (only 4 and 5 pins). Definitions are different)
PCB size diagram:
Physical picture (there are no curved pins on hand, use straight ones instead)
Connect to the computer and send data:
When sending data, the TX light flashes.
Use STC-ISP to download a program to 89C52, and disconnect the target microcontroller first. After powering on, the pups will be born normally.
CH9340SER.EXE
BOM download
PCB_PCB_CH9340 USB to serial port_2022-09-23.pdf
PCB_PCB_CH9340 USB to serial port_2022-09-23.json
PCB_CH9340 USB to serial port_2022-09-23.pcbdoc
Gerber_PCB_CH9340 USB to serial port_2022-09-23.zip
Schematic_CH9340 USB to serial port module_2022-09-23.pdf
SCH_CH9340 USB to serial port module_2022-09-23.json
Sheet_1_2022-09-23.schdoc
61649
electronic
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IS42VS16400C1-12TI
