Standard fan PWM frequency

Hello everyone,

I have been looking on google for a while, what PWM frequency does the part fan run at? But I cant find answer. I am designing a closed loop speed control circuit, The circuit needs a steady input voltage, so the op-amp can do its thing. So I am adding a low pass filter before the circuit. It would be nice to know the PWM frequency so I dont have to hunt and peck to find the values for the filter.

Thanks

I think that that depends on the timers on the board:
[www.arduino.cc]
(I guess that Marlin uses the built-in Pwm function of Arduino)

Another guess would be that a Signal based on a 20ms Cycle, wich would be normally used to control brushless motors is used.

I also found this:
[www.google.ch]

See Point 2.1.4

Edited 1 time(s). Last edit at 08/20/2017 11:32AM by PantherPlayz.