"24V DC Cooling Fan" governor signal line is connected to the thermistor temperature signal is generally used as a temperature sensor for temperature sampling. Changes lead to changes in temperature thermistor resistance, and therefore there is no input signal polarity. DC fan tachometer signals are generally plug output from the three leads, three leads in yellow and black, respectively + 12V power and ground, another color line is the speed signal output lines. Speed signal "24V DC Cooling Fan" output from the circuit is typically in the form of pulses, each of said fan is turned around the first wave, such signal may be provided directly to the host for display by a data bus. Temperature signal line, manual governor is actually a variable resistor, the resistance to the minimum (or a short jumper) when the minimum fan speed, maximum resistance (or unplugged jumper) AC fan at full speed operation. "24V DC Cooling Fan" random attachment has two drives, one of which can be selected according to the situation. As long as you want thermistor is placed between the CPU and the heat sink, and then pulling on the yellow jumper fan signal lines, cooling fan of the yellow video cable, connect the signal line temperature measurement is complete.