How Are Each Of The Five Wires in The Cooling Fan Defined?

Our common cooling fan has two lines, namely the red and black power lines, the red line is positive, and the black line is negative, collectively known as red positive and black negative. However, as users' requirements for cooling fans increase, cooling fans are constantly upgraded and upgraded to three or four lines. Let's first discuss the role of the third line of the cooling fan.
The third and fourth lines are the functional signal lines of the cooling fan, with one being the RD alarm signal and the other being the FG speed measurement signal. The RD alarm function is a rotation detection function, which outputs a low level signal pin when the cooling fan is running and a high level signal when the rotor is blocked; FG speed measurement signal This is a open collector output linked to a "pull-up" resistor and the input power voltage of a compatible reading device. This output provides a square wave signal that is a frequency generator or output tachometer.
There are also PWM speed control signals and temperature control signals. When the temperature control function signal is applied, the fan speed is controlled by temperature when the cooling fan is running, and different temperatures can correspond to different speeds; The PWM speed regulation function can use frequency and high and low voltage levels to control the fan speed. In this function, the frequency can be adjusted from -, the high voltage range can be adjusted from 3V to, and the low voltage range is less than or equal to 0.8V. The fan speed can be linearly controlled by adjusting the "duty cycle" until the maximum fan speed is reached.