MOSFET pick, 12v, 24v, control

I thought I understood enough, but apparently not enough to pick what i need!

I want to control a 12V power (fan speed) and another 24V power (LED).
So I'll be using PWM as the signal from analogWrite pin, 12 or 24V as the source.

Seems any of these would do. Did I read correctly?

How do you chose?

Any power MOSFET will do for what you need. The voltage rating is only important if you're doing high voltage stuff. As long as the current is high enough then you should be ok too

is this (below) your circuit for the fan?

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Adafruit and Sparkfun have a mosfet to be used with an Arduino:

Most power mosfets that turn on with a low VGS are probably okay. Using a 60A mosfet for a 0.1A fan is normal.

Some fans with a separate pwm-wire want a 50kHz PWM signal. Some fans are not suitable to be used with a PWM to the power wires. Do you have the details of that fan ?

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I think the diagram is correct. if M is the fan, yes. So looks like I'm fussing for nothing and they will work. I'll order a few and see the difference.

Koepel: no, the fans are not PWM themselves. They are standard 3 wire fans, 12V and 0.18A, computer fans. I'm not sure how I would use a PWM fan, I didn't look into it as I didn't have any on hand.

Will I need to do a low pass filter on the power for the fan? Or will it not matter? I didn't run tests yet.

There is no such thing as a standard computer fan.
The third wire is for the rpm output.
Some fans allow that the 12V is a PWM signal and some don't.

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