Piezoelectric fan
AssigneeMurata Manufacturing Co., Ltd.
InventorsYasuo Yamada, Katsumi Fujimoto, Jiro Inoue
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Abstract
A piezoelectric fan includes a tuning-fork type vibrator having two sides. A first piezoelectric element is formed on each of the two sides of the vibrator. Further, an exciting electrode is formed on each of these first piezoelectric elements. Also, a feedback electrode is formed on one of the first piezoelectric elements an electrically insulated from the exciting electrode. Furthermore, a blade is attached to the tip of each of the two sides of the vibrator. Then, this piezoelectric fan is driven in a self-exciting fashion by feeding an output from the feedback electrode to the exciting electrode. Also, in this piezoelectric fan, a vibrational node is formed at nearly the middle point of the vibrator at free vibration.
Claims11
A piezoelectric fan comprising;
- a tuning-fork type vibrator having two vibrating sides which have tips,
- a first piezoelectric element formed on a face of each of said two sides,
- an exciting electrode formed on each said first piezoelectric element,
- a feedback electrode which is formed on one of said first piezoelectric elements and electrically insulated from said exciting electrode, and from which an output is fed to said exciting electrode, and
- a fan blade secured to each of the tips of said two sides.
A piezoelectric fan comprising:
- a tuning-fork type vibrator having two vibrating sides which have tips,
- a first piezoelectric element formed on a face of each of said two sides,
- an exciting electrode formed on each said first piezoelectric element,
- a feedback electrode which is formed on one of said first piezoelectric elements and electrically insulated from said exciting electrode, and from which an output is fed to said exciting electrode,
- a fan blade secured to each of the tips of said two sides,
- which further comprises a feedback loop from said feedback electrode to feed said output to said exciting electrode,
- wherein said feedback loop comprises an amplifier circuit,
- an oscillation circuit being formed with said piezoelectric element and said amplifier circuit and said output being fed to said exciting electrode from said oscillation circuit,
- which further comprises a wave shaping circuit which is inserted into said feedback loop to shape said output given to said exciting electrode into a trapezoidal wave.
Dependencies are inferred from the claim text.