| 摘要 |
PURPOSE:To make it possible to place an electric part near to an ultrasonic motor and cool an inside of electric equipment with low power consumption, by providing a driving circuit on a board for supplying the ultrasonic motor with an electric signal to rotate a fan-shaped rotor thereof. CONSTITUTION:An ultrasonic motor as a cooling unit is made up of an oscillator 1 having a plurality of electrodes, a first rotor 2, and a second rotor 3. A voltage of sine wave signal or cosine wave signal is applied to each electrode so that the oscillator 1 is expanded or shrunk by distortion in accordance with the frequency of the signals. Then, the first and second rotors 2 and 3 are rotated when the oscillator 1 is fitted to the first and second rotors 2 and 3 through the expanding or shrinking operation. The ultrasonic motor is mounted on a board 6, and air pipe holes 5A to 5C are also formed on the board. Consequently, the heat from an electric part is diffused on the board by rotating the fan-shaped rotor 2. |
