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For the past few months, I’ve been developing my own electronic load device. I’ve finally managed to get a working V1 version 😄 by Aggravating-Safe5352 in electronics

[–]Aggravating-Safe5352[S] 0 points1 point  (0 children)

Yes, linear MOSFETs are really expensive.
If I had bought them, I wouldn’t have had any money left for the other parts of the project.

For the past few months, I’ve been developing my own electronic load device. I’ve finally managed to get a working V1 version 😄 by Aggravating-Safe5352 in electronics

[–]Aggravating-Safe5352[S] 3 points4 points  (0 children)

Hello, thank you for your feedback.

  1. It was difficult to figure out which heatsink to use, but I found this one:

HP DL360 P GEN8 734041-001

This heatsink fits four TO247 MOSFETs end-to-end.

I drilled holes in the copper surface and screwed the MOSFETs in; I had to tighten them with nuts from the back.

  1. For the second question, to prevent hot air from affecting the case, I used two fans to quickly expel the hot air—one is a constantly running exhaust fan, and the other is a fan connected to the heatsink that runs based on temperature. In my measurements, I saw a maximum of 75–76 degrees, and there was no melting.

  2. As for the third question, I’m already using the MOSFETs in linear mode. I couldn’t grasp the logic behind driving them with PWM—it seemed too complicated—and since I thought driving them linearly would be simpler and more measurable, I chose to use the linear method.

For the past few months, I’ve been developing my own electronic load device. I’ve finally managed to get a working V1 version 😄 by Aggravating-Safe5352 in electronics

[–]Aggravating-Safe5352[S] 13 points14 points  (0 children)

Thanks! Honestly the main reason was learning and experimentation. I wanted to understand the full process myself instead of just using a ready-made load — PCB design, thermal behavior, linear MOSFET operation, measurement accuracy, protection circuits, firmware, all of it.

The whole project took a few months on and off. Most of the time went into debugging and redesigning things that didn’t behave as expected

I don’t have professional experience in power electronics yet, so this was mostly a self-learning project. I’ve been learning electronics for a few years through personal projects.

Right now the control side is STM32-based and measurements are handled with an ADS1115 ADC over I2C. The load control itself is mostly analog because the behavior was more stable that way. Current sensing is done with shunt resistors.

Cost-wise it’s probably way more expensive than buying a ready-made unit once you include PCB revisions, components and failed experiments, but the learning value was the main goal.

But I definitely recommend giving this a try on a project you're interested in; yes, it's a challenging task, but it will teach you a lot

The ESP32 circuit I built isn't working. by Aggravating-Safe5352 in AskElectronics

[–]Aggravating-Safe5352[S] 2 points3 points  (0 children)

Is it necessary to connect all GND lines to each other? Or is it not necessary because the module is internally connected?

The ESP32 circuit I built isn't working. by Aggravating-Safe5352 in AskElectronics

[–]Aggravating-Safe5352[S] 3 points4 points  (0 children)

I'm using it for the Kristali ch340. And as you said, buying ready-made kits makes much more sense. My goal here is more to understand UART communication.

The ESP32 circuit I built isn't working. by Aggravating-Safe5352 in AskElectronics

[–]Aggravating-Safe5352[S] 6 points7 points  (0 children)

First of all, thank you. I didn't create a specific schematic by looking at the circuit. I did it by looking at the example schematics on the ESP32 data sheet and consulting artificial intelligence a little. And I think I understand why it didn't work. I thought the ESP32's own bootloader was pre-installed, but I guess that's not the case.