# Fifth Lichuang Electronic Design Competition# Multi-linear DC regulated power supply for debugging ±5V+3.3V±20V mV level adjustable output

Note: * is required.

[Please fill in during the registration stage↓]
* 1. Self/Team Introduction
I only noticed this electronic design competition when I logged in to Jialichuang today, and saw that there were only 4 days left before the deadline. I'm also hesitant to try it again.
I am an electronics enthusiast. I started to learn electronics by myself in high school. I have been tinkering around in various ways. I have designed and produced not many but not many things.
But looking back now, it’s hard to think of a product that truly strives to be the best.

* 2. Briefly introduce the project
. The project you signed up for is a linear regulated power supply that anyone new to electronic technology can have access to.
The chips used are very common and easily procured. It is such a simple linear regulated power supply that has been made in so many versions for such a long time. I can only say that I am too busy and too impetuous.
The normal state is one project after another, lacking the continuous ability to do a very simple thing well, and the lack of continuous investment and research.
This project doesn’t look fancy or cool. Going back to the topic, let’s take a look at this very simple linear regulated power supply.

On September 20, 2020, I received the proofing PCB board this afternoon. Start welding test.


[Please fill in during the competition stage↓]
* 1. Describe the project details.

This power supply can be traced back to before 2012. Hahaha, it has been occasionally upgraded and iterated for more than 7 years. When I first came into contact with circuit design, I was lacking a power supply that could be used for testing. I hope it can help enthusiasts from various schools conduct experiments more conveniently and arouse their love for hands-on work!
When you are a student, you have to save up for a long time to buy multimeters and various components. Linear regulated power supply, after years of use and technology accumulation. Linear regulated power supplies are often used for experiments, debugging and testing.
Although there are ready-made power supplies for sale, they are often troublesome due to the insufficient number of power output channels or inconvenience to carry.
This power supply has experienced more than 7 years of technical iteration and continuous upgrading. It has been used in the technical development and testing of multiple products, and has been used in batches in many national technology competitions. Another iterative upgrade, the V5.13 version [https://www.cirmall.com/circuit/18425](https://www.cirmall.com/circuit/18425) has been open sourced in Circuit City.
This time it’s updated and designed again.

* 2. Describe the challenges faced by the project and the problems it solves
:
1. How to balance the performance and cost of linear regulated power supply?
2. When electronic engineers usually debug circuits, which type of linear regulated power supply is more commonly used?
Problem solved:
A multi-line linear regulated power supply is designed, which is suitable for common circuit debugging occasions. Positive and negative 5V, positive and negative 3.3V, positive and negative adjustable 20V output. The power of each channel is not large, roughly within 400mA.


* 3. Describe the key points involved in the hardware and software parts of the project.
Hardware: The heat sink of the previous version of the linear voltage stabilizer power supply was too small. Due to the heat dissipation power of the linear voltage regulator chip, the heat sink is increased in this version. area.
Circuit schematic:
![Picture.png] PCB LAYOUT :
![Picture.png] ![Picture.png]
![Picture.png]



* 4. Project material list display

| | | | | | |
| --- | --- | --- | --- | --- | --- |
| Comment | LibRef | Designator | Footprint | Quantity
|
| C8,C12,C16 | 35V2200UF | 4 | | | |
| 2 | 100V104J | CBB in-line ceramic capacitor | C3,
| | | | | 3 | 50V2200UF 16X25 | High frequency direct plug electrolytic
capacitor | C11, | | |
| C18 | 50V2200UF | 2 | C15 | CAPPR4-5x11mm | 2 | | | | | 5 | 10V2200UF volume 10X20 | High frequency in-line electrolytic capacitor | C1 , | | D1, | | | | D2, D7, D8, D14, D18, D20 | SMA(DO214-AC) | 7 | | | | | 7 | DB207S | DB207S Chip Rectifier Bridge | D3, | DB207S | 2 | | | | 8 | 0805 LED | 0805 LED | LED9, | | | | LED10, LED11, LED15, LED16 | LED0805_G | 5 | | | | | 9 | 5.08mm 3P terminal block | H3*1 | P1, | | | | P3, P4, P10 | H3*1D_4.6mm | 4 | | | | | 10 | 5.08mm 2P ​​terminal block | H2*1 | P2, | | | | P5 | | | | | 11 | 2.54mm double row connector | H3*2 | P7, | | | | P8 | H3*2_1 | 2 | | | | 12 | 2.54mm double row connector | H2*2 | P9 | H2*2 | 1 | | 13 | 0805 12K | RES1 | R1, | | |


















| R4, R8, R9 | R0805 | 4 | | | |
| 14 | 0805 5K | RES1 | R2, | | |
| R3, R5 | R0805 | 3 | | |
| | R6, | | |
| R7 | AXIAL-0.4 | 2 | | |
| 16 | Potentiometer 3590S-2-502 | Multi-turn potentiometer | RW1 ,
|
17 | Potentiometer knob | | | | 2 |
| 18 | AMS1117-3.3 | LDO chip | U1 | SOT-223 | 1 |
| 19 | L7805CV | 7805 chip ST imported brand new original | U2 | TO-220AB-LAY | 1 |
| 20 | L7905CV | 7905 chip ST imported new and original | U3 | TO-220AB-LAY | 1 |
| 21 | LM317T | LM317 chip ST imported new and original | U4 | TO-220AB-LAY | 1 |
| 22 | LM337T | LM337 chip imported brand new and original | U5 | TO-220AB-LAY | 1 |
| 23 | Copper pillar | Copper pillar | Fixed hole 1, fixed hole 2, fixed hole 3, fixed hole 4 | Fixed hole 1 | 4
| Copper pillar screws | Copper pillar screws | | | 4 |
| 25 | Customized black aluminum heat sink | Heat sink | | | 1 |
| 26 | Heat sink screws | Heat sink screws | | | 4 |
| 27 | TO-220 insulation Cap | TO-220 Insulating Cap | | | 4 |
| 28 | Thermal Insulation Sheet | Insulating Silicone Sheet | | | 4 |
| 29 | Power Board PCB Board | V5.15 |
| 3.2_7_6 | Fixed heat sink and PCB board | | | 4 |
| 31 | M3 double-pass hexagonal copper column M3*20 | Fixed heat sink and insulation board | | | 4 |
| 32 | Customized acrylic board or insulation board | 3mm thick ,           see           the customized


drawings | | .png] Jialichuang's PCB proofing speed is quite fast, and PCB proofing is done twice a month. I wasn't sure whether to publish it or not, but now that it's here I'll give it a try. ![WeChat screenshot_20200921000254.png] ![WeChat screenshot_20200921000328.png] Soldered circuit board, I am a player who is not good at soldering circuit boards. Hahaha~ ![WeChat Picture_20200920235919.jpg] ![WeChat Picture_20200920235950.jpg] * 6. Demonstrate your project and record it as a video for upload           6.1, Video Upload Contest official website           6.2, Station B video title and link The fifth session Lichuang Electronic Design Competition# Multi-line linear DC regulated power supply for debugging ±5V+3.3V±20V mV level adjustable output [https://www.bilibili.com/video/BV1Ya4y1j7TS/](https://www. bilibili.com/video/BV1Ya4y1j7TS/) Notes: ①: Video requirements: Please shoot horizontally, with a resolution of no less than 1280×720, format Mp4/Mov, and the size of a single video is limited to 100M; ②: Video upload: please synchronize Upload to the official website of the competition and Station B ([www.bilibili.com](www.bilibili.com)). The top 10 most popular projects at Station B will receive cash rewards of 1,000-5,000 yuan. Other uploaded projects will receive a 100-yuan Lichuang Mall no-threshold coupon. ; ③: Video title: The 5th Lichuang Electronic Design Competition: {Project Name}-{Video Module Name}; For example, the 5th Lichuang Electronic Design Competition: "Autonomous Driving" Project - Team Introduction. * 7. Whether it is released to the public for the first time.           7.1. Whether the project has been published or won an award before. Please indicate that this version of the project is released for the first time.           7.2. If the project is optimized on the original basis, please explain that the optimized part is replaced with a large heat sink, the circuit layout is optimized, and the interface of the expandable part is added. * 8. Open source documents * 9. References Click the link for more details: [https://www.szlcsc.com/go/dsxq](https://www.szlcsc.com/go/dsxq)