Hi -
I'm curious if anyone has technical information (schematics, theory of operation, etc.) regarding the genre of DC fans that have an additional set of input contacts that allow a thermistor to be attached giving the fan a built in speed controller. I have been searching and have had no luck in how they are accomplishing this functionality. I am speculating it is quite straight forward but would like to see a schematic or a block diagram. I'm guessing these fans are not particularly popular and PWM style fans are the current 'go-to' style.
If anyone would please point me to some technical info, it would be appreciated.
Thanks
Jim