Patent ID: 8061152

Claim:
A wind speed detecting circuit for detecting a wind speed of an airflow passing through a dust-proof element of an electronic device, said wind speed detecting circuit comprising: a heating unit; a first temperature sensor for detecting a first temperature of an internal portion of said electronic device, thereby generating a first detecting signal; a second temperature sensor connected with said heating unit for detecting a second temperature of said heating unit, thereby generating a second detecting signal; a control unit connected with said first temperature sensor and said second temperature sensor for generating a modulation signal according to said first detecting signal and said second detecting signal; and a driving unit connected with said heating unit and said control unit for generating a driving signal to control operations of said heating unit in response to said modulation signal, so that a temperature difference between said first temperature and said second temperature is maintained constant, wherein a specified relation between said wind speed and said modulation signal facilitates discriminating whether said dust-proof element needs to be replaced.