ฝัง
- เผยแพร่เมื่อ 29 พ.ค. 2024
- 5A Digital Adjustable DC Load Circuit
======================================
Article:
======================================
Altium Designer + Legal License (Free): www.altium.com/yt/myvanitar
======================================
Altium 365: www.altium.com/altium-365
======================================
OctoPart: octopart.com
======================================
Other Videos: bit.ly/2N9OlPa
======================================
A DC load is an essential testing tool for any electronic enthusiast, especially for testing and repairing power supplies. An adjustable DC load can limit the current at any desired level, which makes it suitable to perform various tests because some problems of the feedback loop are only detectable by variable load tests. Also for any SMPS repair attempt, the output should be tested against some loads, not just voltage stability, because the problem might lie within the current sensing on the primary side (a common problem of Flyback SMPSs).
This article introduces a digital DC load with a 1.54-inch OLED display to read the load's voltage, current, and power simultaneously. An accurate Texas Instrument zero-drift INA219 current sensing chip reads the voltage and current values and sends the data through an I2C bus to the ATMega328 microcontroller. The microcontroller makes the calculations and displays the values on an SSD1309 128*64 1.54-inch OLED display. The interface between the MCU and display is HW SPI. A zero-drift rail-to-rail input-output Opamp such as the GS8552-SR and some passive components enhance the stability of the CC circuit. The reference voltage of the Opamp has been stabilized using a TL431 shunt regulator.
The schematic and PCB have been designed using Altium Designer 24 and the Gerber files are provided to download from the Altium-365 cloud space. You can power the board using your mobile phone USB Type-C charger; no external power supply is necessary. - วิทยาศาสตร์และเทคโนโลยี
![ช่วยพาฉันผ่านเวลา - วสันต์17 [Official MV]](http://i.ytimg.com/vi/HFnntWoqc54/mqdefault.jpg)
5A Adjustable Digital DC Load Circuit
سلام. هم میهن محترم خیلی ممنون از بایت به اشتراک گذاری این مدار خیلی مفید و کاربردی... اما لطفا" به فکر ما هم باش و نقشه شماتیک، فیبر مدار و برنامه پروژه را در جایی خارج از آلتییوم دیزاینر هم آپلود کن تا هم میهنان هم بتونند استفاده کنند...
Let me reply in English. Just follow the link in the description and activate your free legal license. if you did not upgrade, it doesn't matter, you can download projects from Altium-365. I'll put a link to the article later on where you can find the 365 link as well
Thank you for sharing this 😊
My pleasure 😊
Sweet
Nice my friend
Thank you 👍
@@MyVanitar 🙋♂️🙋♂️👍👍👍
Wwonderfull design thanks for showing the same ! - but the article link looks like missing in the video description can you please look into that.
Thank you. I will provide the article link as soon as it gets published. by the way, watch the video completely till I put that link because you get values from both.
Thank you. I will provide the article link as soon as it gets published. by the way, watch the video completely till I put that link because you get values from both.
@@MyVanitar Thankyou for the reply, sure watched it fully , thankyou for your wonderful explanation of the design as well in the video .
Where is the link to the Altium-365 cloud where you shared this project ?
for this project, the link is inside the article which I'll put the link to the article later on, however, from now on (whatever is published after this), the link to the Altium-365 project will be provided directly in the video description.
Traces for voltage drop sensing on shunt resistors network is far from best practices. You included a noticeable part of copper traces as path for current. It will cause less stable real current when the device is heating. It's not an issue for a hobby project, but you learn here people to do things properly, right? So, that's why I'm pointing this here for you.
I did not get what you meant, what's the problem with this layout?! when the copper is enough, it won't heat noticeably. open a channel and show your professional projects and do things properly!
@@MyVanitar I was talking about PCB traces layout. Traces where you sense voltage drop on shunt resistors. I'll be happy to continue discussion after you have a look on some doc. Please search for AD's document optimize-high-current-sensing-accuracy.pdf and have a look.
That's much more close look how to properly do tracing, while on your PCB it's far from proper approach.
Do not get me wrong, I'm watching your channel not to make critics. I've just spot this and want to pay attention.
Will be happy to continue discussion.
@@MyVanitar I have to repeat a lost comment. I was talking about PCB traces layout. Traces where you sense voltage drop on shunt resistors. I'll be happy to continue discussion after you have a look on some doc. Please search for AD's document optimize-high-current-sensing-accuracy PDF and have a look.
That's much more close look how to properly do tracing, while on your PCB it's far from proper approach.
Do not get me wrong, I'm watching your channel not to make critics. I've just spot this and want to pay attention.
Will be happy to continue discussion.
The "maximum" power dissipation on the shunt is around 1.25W. the shunt is rated at 6W. can be increased to 8W. Resistors on the source pin of the Mosfet are rated at 12W and can be increased to 16W. maximum power dissipation on those 4 resistors 6W but they won't affect the current reading. This can be even improved if the value is decreased but the user would miss low current adjustments. Load ground and input ground are also common. current sensing is the high side method. if you mean the traces from the shunt to the chip, they are short and identical
@@MyVanitar I'm sorry, but you are still wrong and/or do not understand what I mean. Did you found the pdf I mentioned? Read it please!
Your math about shunts wattage does not eliminate the fact that traces for main current sensing shunt (R9 || R10) are placed in a way that violate well known, proper tracing. Those sensing traces literally should go under shunts and have to be connected to internal side of pads where they soldered.
Not like you have right now on one side which we see, it's even on some distance from soldering pads!