Hey everyone! I'm in search of a really small PWM speed controller that can work with a 3.7V lithium battery. Ideally, it needs to be no larger than 18mm square. I've been having a tough time finding one that fits the bill and might even consider building my own if I have to. If you have any suggestions or links to suitable products, I'd really appreciate it! Thanks a lot!
4 Answers
So, I’m working on a project with a mini matchbox RC car. It originally has just one speed—fast. I’m planning to use the battery and motors from it in an IKEA toy train I 3D printed, but I need a speed controller that fits within the cavity, which is about 18mm wide. That's why I'm here!
You could use any small surface mount microcontroller, though it might seem a bit overkill just for PWM. They’re really cheap, though! Also, consider using the tiniest size of this chip: https://www.ti.com/lit/ds/symlink/mspm0c1104.pdf?ts=1760093836272&ref_url=https%3A%2F%2Fwww.ti.com%2Fproduct%2FMSPM0C1104. Just keep in mind that you’ll need a motor driver to actually run the motors—if you just need one direction, a small MOSFET with an integrated flyback diode will work fine, assuming it can handle your current needs.
Could be a little unclear without more details. You can use a 555 timer for PWM control, but I’d need to know what input and output you’re working with, the current requirements, and what you’re actually driving (like a motor) to give better advice.
I found something that might work! Check this link:
https://www.aliexpress.us/item/3256806011094123.html. You might have to trim the ends a bit to get it to fit your space, though!
Thanks for the link! The size looks perfect, but I don’t see a knob or screw for speed adjustment. Any ideas on how I could control the speed with this?
Just remember, the key to good design is often to choose the PWM board first and then build your project around it!