Patent ID: 7291995

Claim:
An air fan rotation speed control method, comprising: setting an air fan control mode; an air fan rotation speed control system having a built-in automatic control mode to detect heat dissipation conditions of an environment in order to output a speed regulation signal to regulate the rotation speed of an air fan, and a manual control mode to execute an air fan rotation speed regulation command to regulate the rotation speed of the air fan; and selecting an air fan control mode; under the manual control mode in a condition of not executing the air fan rotation speed regulation command, the rotation speed control system controlling the air fan rotation speed through the automatic control mode; under the manual control mode in a condition of executing the air fan rotation speed regulation command, the manual control mode being enforced to be executed when the regulated rotation speed value under the air fan rotation speed regulation command is higher than the regulated rotation speed value under the automatic control mode; the regulated rotation speed value under the automatic control mode being maintained when the regulated rotation speed value under the air fan rotation speed regulation command is lower than the regulated rotation speed value under the automatic control mode.