Hello all!
I'm building a custom toolchanger with e3d toolhead and toolplates, and I was having problems with fans not reacting to PWM or being very whinny/loud/weak as soon as I PWM'd them, so I'm designing a very simple circuit with an low pass configured opamp and a transistor that should give a nice and stable analog voltage from the PWM signal from the duet.
Since I'm lowpass filtering in small signal, no inductors are needed, just a couple of resistors and capacitors, EMI should not be a problem, and the pcb should be very small.
My aim is just to use an all 24V system, but it would be rather easy to make the circuit voltage-agnostic so you could be able to mix and match fan voltages in the future.
Is anyone interested in such a circuit? I'm thinking about having some pcb boards manufactured, and since most services are about 20 pieces minimum order, I will have plenty of them...
Any thoughts?
Also posted this in duet forums (hope it does not break any rule...)
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forum.duet3d.com]