本文介绍了一种基于AT89C52单片机的智能电风扇调速器的设计，该设计主要硬件部分包括AT89C52单片机，温度传感器ds18b20，数模转换DAC0809电路，电机驱动和数码管显示电路，系统可以实现手动调速和自动调速两种模式的切换，在自动工作模式下，系统能够能够根据环境温度实现自动调速；可以通过定时切换键和定时设置键实现系统工作定时，使得在用户需求的定时时间到后系统自动停止工作-This paper describes an approach based on AT89C52 intelligent fan speed controller design, the design of the main hardware includes AT89C52 microcontroller, temperature sensor ds18b20, DAC0809 digital-analog conversion circuit, motor drive and digital display circuit, the system can be achieved manually adjust switching speed and automatic speed modes, in automatic mode, the system can automatically adjust speeds according to the ambient temperature to achieve　may switch key by key timing and timing settings to achieve the system work regularly, so that the user needs regular time to after the system automatically stops working really