I have a 91mm fan "9232-12HBTL" made by Datech. It has a sensor output. My question is: how do I use it? How's the information outputted? Pulses? Voltage?
typicall it is a ttl level 0-5V square wave that is usually either 2 or four pulses
per revolution. It is a pretty easy signal to deal with as it can be read by most
general purpose microcontrollers.
I commented about one of these at some point (but I cant find the post).
The few that I have are all open collector outputs. So you must use a
pull-up resistor on the sensor output. Mine did have hall effect sensors
inside them.