1. Soft start function: When supplying power to the fan, the current increases gradually from zero until the fan reaches the maximum speed and rated current. The maximum starting current is equal to the free running current, and the fan will reach the rated speed within the specified time (5 seconds for Yongyihao).
2. Self starting function: it can provide locking protection and restart the current limiting function. The self starting function is to ensure that the fan motor will restart automatically to prevent the fan blades from being blocked. When the rotor is locked, the current of the fan will be reduced to zero, and the fan will restart automatically in 5 seconds.
3. FG speed detection function: equivalent to frequency generator or output tachometer, this is the input power voltage of a collector open circuit output connected to a pull-up resistor and a compatible reading device. This output provides a square wave signal (such as TTL input computer). The maximum collector voltage may be as high as 72 V DC and the maximum collector current 10 MAA. The power supply of the reading device must have the same ground potential as the fan.
4. RD rotation detection function: this is an open collector function, which has similar hardware functions to FG. There are two cases: the signal pin outputs low level when the Class A fan is running, and high level when the fan is blocked and stops running; The signal pin of Class B fan outputs high level when it is running, and low level when the fan is blocked and stops running.
5. PWM pulse width speed regulation control function: PWM function can use frequency and high and low voltage levels to control fan speed. The fan speed can be linearly controlled by adjusting the duty cycle. PWM speed regulation is generally four wire control. At present, PWM speed regulation+RD signal function is widely used.
6. Automatic temperature control function: The speed of the fan is controlled by the temperature. Different temperatures can correspond to different speeds.
