VOLUME CONTROL DEVICE SUITABLE FOR UNITERRUPTIBLE POWER SYSTEM

A volume control device suitable for an uninterruptible power system comprising a fan is provided. The volume control device comprises a user interface and a control circuit. The control circuit is electrically coupled to the fan and the user interface, and is used to receive a maximum operation volume setting value through the user interface. When the control circuit is ready to increase the rotation speed of the fan, it further determines whether the corresponding volume of the current rotation speed of the fan is less than the maximum operation volume setting value, and accordingly determines whether to adjust the rotation speed of the fan.