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Ich habe vor, einen PC-Lüfter mit PWM-Eingang zur Drehzahleinstellung...
20 Sekunden googlen:
What are the electrical parameters of PWM fans?
Electrically the PWM signal is TTL/CMOS compatible where the PWM input impedance is greater than or equal to 10 Kohm. The PWM operating frequency is 25 KHz +/- 5 KHz. The maximum voltage for a low PWM signal is 0.8 Vdc and the minimum voltage for a high PWM signal is 2.0 Vdc
1 Minute googlen:
http://www.formfactors.org/developer...e_PWM_Spec.pdf