Hi Christian, > You ar right, but the meter should integrate, shouln?t it (the fan does > anyway) > What I can see is, when setting 0...255 in pwm2, this translates to 0..5 V > roughly linear on the meter. > 255 should mean "almost always on" and should result in something close to > 12V, isn?t it? But I can measure only 5V.... The meter is digital. The ADC has a high sample rate and integrates piecemeal. Or I could be wrong about your meter. However, you are right about needing to do more research. A cheap way to measure peak voltage is to charge a capacitor in series with a diode. It will reach peak voltage but not discharge. Then you (might) be able to measure it with your meter. > No I think there might be more secrets behind 4-pin fans than I know... > maybe these fans use TTL logic type voltages to influence electronic > communtation internally..... > We might need to reseearch in the internet her David
