本设计为一种温控风扇系统，具有灵敏的温度感测和显示功能，系统采用51系列单片机AT89C51 单片机作为控制平台对风扇转速进行控制。利用DS18B20数字温度传感器采集实时温度，经单片机处理后通过三极管驱动直流风扇的电机。根据采集的实时温度，实现了风扇的自起自停.可由用户设置高、低温度值，测得温度值在高低温度之间时打开风扇弱风档，当温度升高超过所设定的温度时自动切换到大风档，当温度小于所设定的温度时自动关闭风扇，控制状态随外界温度而定。(This design is a temperature control fan system with sensitive temperature sensing and display function. The system uses 51 series single chip AT89C51 as the control platform to control the fan speed. DS18B20 digital temperature sensor is used to collect real-time temperature, and the motor of DC fan is driven by triode after being processed by MCU. According to the collected real-time temperature, the fan can start and stop automatically. The user can set the high and low temperature values. The measured temperature values between high and low temperatures can open the weak fan gear. When the temperature rises above the set temperature, the fan can be automatically switched to the big fan gear. When the temperature is lower than the set temperature, the fan can be automatically closed. The control state depends on the external temperature.)