Control Circuit and Fan Comprising the Same

Abstract

A control circuit and a fan comprising the same are provided. The fan comprises a plurality of windings. The control circuit comprises a temperature sensing module and an adjusting module. The temperature sensing module is configured to sense an environmental temperature to generate a temperature signal. The adjusting module is coupled to the windings and is configured to change a connection between the windings in response to the temperature signal to adjust an impedance value of the fan, wherein the fan is a fan, the adjusting module adjusts the impedance value of the fan in response to the temperature signal to change a rotational speed of the fan.

1 . A control circuit applied in a fan, the fan comprising a plurality of windings, the control circuit comprising:
 a temperature sensing module configured to sense an environment temperature to generate a temperature signal; and   an adjusting module, being coupled to the windings and configured to change connection between the windings in response to the temperature signal to adjust an impedance value of the fan;   wherein a rotational speed of the fan is changed according to the impedance value.   
   
   
       2 . The control circuit as claimed in  claim 1 , wherein the connection between the windings is one of series connection, parallel connection, and a combination thereof. 
   
   
       3 . The control circuit as claimed in  claim 1 , wherein the windings comprises a first winding and a second winding, the fan further comprises a switch element, the adjusting module outputs an adjustment signal in response to the temperature signal to turn on the switch element, and the first winding and the second winding are coupled in series via the switch element to adjust the impedance value of the fan. 
   
   
       4 . The control circuit as claimed in  claim 1 , wherein the windings comprises a first winding and a second winding, the fan further comprises a first switch element and a second switch element, the adjusting module outputs an adjustment signal in response to the temperature signal to turn on the first switch element and the second switch element, and the first winding and the second winding are coupled in parallel via the first switch element and the second switch element to adjust the impedance value of the fan. 
   
   
       5 . The control circuit as claimed in  claim 4 , wherein one of the switch elements is a metal-oxide-semiconductor field-effect transistor (MOSFET). 
   
   
       6 . The control circuit as claimed in  claim 1 , wherein the adjusting module changes the rotational speed of the fan through the pulse width modulation (PWM). 
   
   
       7 . A fan, comprising:
 a plurality of windings; and   a control circuit, comprising:
 a temperature sensing module configured to sense an environment temperature to generate a temperature signal; and 
 a adjusting module, being coupled to the windings and configured to change connection between the windings in response to the temperature signal to adjust an impedance value of the fan; 
   wherein a rotational speed of the fan is changed according to the impedance value.   
   
   
       8 . The fan as claimed in  claim 7 , wherein the connection between the windings is one of series connection, parallel connection, and the combination thereof. 
   
   
       9 . The fan as claimed in  claim 7 , wherein the windings comprises a first winding and a second winding, the fan further comprises a switch element, the adjusting module outputs an adjustment signal in response to the temperature signal to turn on the switch element, and the first winding and the second winding are coupled in series via the switch element to adjust the impedance value of the fan. 
   
   
       10 . The fan as claimed in  claim 7 , wherein the windings comprises a first winding and a second winding, the fan further comprises a first switch element and a second switch element, the adjusting module outputs an adjustment signal in response to the temperature signal to turn on the first switch element and the second switch element, and the first winding and the second winding are coupled in parallel via the first switch element and the second switch element to adjust the impedance value of the fan. 
   
   
       11 . The fan as claimed in  claim 10 , wherein one of the switch elements is a metal-oxide-semiconductor field-effect transistor. 
   
   
       12 . The fan as claimed in  claim 7 , wherein the adjusting module changes the rotational speed of the fan through the pulse width modulation.