How does the fan speed control work on the Einsy Rambo board? I want to make it work with a 2-pin 24V fan
The part cooling fan runs on 5V. I know it uses a 3 pin fan so it probably uses the tachometer.
If it just does PWM 0-100% on the +5V pin I could use a transistor to drive the 24V fan.
Any information on how the hardware around fan speed control works would be helpful.
RE:
Fan speed control is very straightforward.
Basically voltage goes out to the fan motor and a FET pulls the low end of the motor down to ground when speed is called for. Tach input closes the loop and that is straightforward.
You will need to do something to simulate the tach output.
I have never tried anything like this, but my guess is that if you take steps to be sure that the tach output back to the board is at the expected levels, yes, you could probably cobble things together to get a 24 volt fan to work, using an external transistor or something.
LOL, Disclaimer: You break it, you own the pieces! 😉
RE: How does the fan speed control work on the Einsy Rambo board? I want to make it work with a 2-pin 24V fan
That's exactly what I needed, thank you!
I was really hoping for high side PWM but I can work with this.
Hacking at my own risk of course. I wouldn't mind blowing this board and swapping for a 32bit SKR with better stepper drivers anyway.