When discussing the speed of the coal mine fan, it can usually be regarded as a DC speed regulating motor, and its speed is mainly changed by adjustable resistance. As long as the controllable rectifier acts on both ends of the motor, the speed of the fan can be controlled.

However, we sometimes encounter problems with unstable wind speed in use. Once such problems occur, it will greatly affect its operation and use. First of all, we must understand the reasons for the unstable wind speed of the coal mine to solve the problem correctly.

1. Due to the four rectification diode of the coal mine fan, there are some problems, which affects the function of the entire device.

2. The carbon powder or carbon brushing of the motor rotor and the directioner is not equal. At this moment, you can first check the adjustable resistance of the fan. If the resistance changes with adjustment, this is very good.

3. The problem may be the crystal tube, such as disconnection, poor touch, short circuit, and unable to touch. In addition, if the barrier resistance is poor, it will also affect the stability of the speed of the coal mine fan.