1、 自动油烟排风扇电路设计 摘 要 自动油烟排风扇的用途比较的广泛，其设计方法的应用更是五花八门，绝大 多数的抽油烟机以及室内空气自洁电路是用自动油烟排风扇来实现的。本次电路 设计的目的就是设计出随烟雾浓度自动报警并开启排风扇的自动油烟排风电路。 该电路主要包含直流电源电路（给系统各部分提供稳定可靠的直流电）信号采集 及处理电路（将空气中的有害气体浓度变化转换为其本身阻值的变化，从而利于 后面的电路处理）触发电路（继电器执行电路） 、声光报警电路（控制声音和红绿 指示灯的电路）和排气通风装置（排除油烟的装置） 。 这种类型的电路能使得排风扇加电即能进入自动监视状态，气敏传感器一旦 检测到油烟或煤
2、气时，就能使排风机自动打开，并发出报警信号；油烟或煤气排 干净时，即能自动关闭风机，停止报警。其路也可适用于温度、湿度、气体等方 面的自动控制设备。 关键词：排风扇，自动监视，气敏传感器 Automatic smoke exhaust fan circuit Abstract The use of automatic smoke exhaust fan more extensive, the application of its design is varied, the majority of range hoods and indoor air self-cleaning circuit
3、with automatic smoke exhaust fan is achieved. The purpose of this circuit is designed with the concentration of smoke alarm and open the automatic smoke exhaust fan circuit. The circuit mainly includes DC power supply circuit (to the parts of a system to provide stable and reliable DC) signal acquis
4、ition and processing circuit (the air concentration of harmful gas conversion for their own resistance to change, to help deal with the back of the circuit) trigger circuit (relay implementation of the circuit), sound and light alarm circuit (control circuit voice and red and green lights) and exhaust ventilation units (excluding smoke device). This type of circuit can make the fan in power that is able to automatically monitor the status of access, once the gas sensors to detect smoke or gas w
