Looking at a review of Noise Control's fan controller atModdin'.net I was wondering, why the 2 opto-isolators on the right of the picture? The only reason I could come up with was to restore the 2 fan speed pulses back to 12v when the fans are running at lower voltages. Is this a problem on any mobos you folk know of? Do you folk with rheostats get good speed recording at low revs? Or any other explanation.
