Fan speed control system

Abstract

A fan speed control system. A temperature and humidity sensing unit detects environmental temperature and humidity and outputs a corresponding electrical signal. A micro-control unit receives and processes the electrical signal to obtain a digital signal, and sends the digital signal to the fan motor circuit to control fan speed accordingly.

1 . A fan speed control system, comprising: 
 a fan motor circuit;    a temperature sensing element detecting environmental temperature and sending a corresponding first electrical signal;    a humidity sensing element detecting environmental humidity and sending a corresponding second electrical signal; and    a micro-control unit receiving and processing the first and second electrical signals to obtain a digital signal, and sending the digital signal to the fan motor circuit to control fan speed.    
   
   
       2 . The fan speed control system as claimed in  claim 1 , further comprising a speed sensing unit detecting the fan speed and sending a corresponding third electrical signal to the micro-control unit.  
   
   
       3 . The fan speed control system as claimed in  claim 1 , wherein the humidity sensing element comprises a humidity-sensitive resistor.  
   
   
       4 . The fan speed control system as claimed in  claim 1 , wherein the temperature sensing element comprises a heat-sensitive resistor.  
   
   
       5 . The fan speed control system as claimed in  claim 1 , wherein the digital signal comprises a pulse width modulation (PWM) signal.  
   
   
       6 . A fan speed control system, comprising: 
 a fan motor circuit;    a temperature and humidity sensing unit detecting environmental temperature and humidity and sending a corresponding first electrical signal; and    a micro-control unit receiving and processing the first electrical signal to obtain a digital signal, and sending the digital signal to the fan motor circuit to control fan speed.    
   
   
       7 . The fan speed control system as claimed in  claim 6 , further comprising a speed sensing unit detecting the fan speed and sending a corresponding second electrical signal to the micro-control unit.  
   
   
       8 . The fan speed control system as claimed in  claim 6 , wherein the temperature and humidity sensing unit comprises a heat-sensitive element, a humidity-sensitive element, and a plurality of resistors.  
   
   
       9 . The fan speed control system as claimed in  claim 8 , wherein the heat-sensitive element and the humidity-sensitive element both comprise resistors.  
   
   
       10 . The fan speed control system as claimed in  claim 6 , wherein the digital signal comprises a pulse width modulation (PWM) signal.