| US 7,564,163 B2 | ||
| Structural vibration damping device | ||
| Junjiro Onoda, Sagamihara (Japan); Shinsuke Takeuchi, Sagamihara (Japan); and Takuya Yabu, Sagamihara (Japan) | ||
| Assigned to Japan Aerospace Exploration Agency, Tokyo (Japan) | ||
| Filed on Jul. 14, 2006, as Appl. No. 11/486,474. | ||
| Claims priority of application No. 2005-255895 (JP), filed on Sep. 05, 2005. | ||
| Prior Publication US 2007/0052325 A1, Mar. 08, 2007 | ||
| Int. Cl. H01L 41/08 (2006.01) | ||
| U.S. Cl. 310—316.01 [310/317; 310/319; 310/321] | 15 Claims |
| 1. A structural vibration damping device comprising:
a piezoelectric element adapted to be mounted on a structure;
a shunt circuit inserted between two electrodes of said piezoelectric element; and
an electric circuit for selectively opening and closing said shunt circuit, wherein:
said electric circuit is operable, when a voltage between the electrodes of said piezoelectric element has a positive or negative
extreme value due to a vibration of said structure, to close said shunt circuit so as to allow a current to flow between the
electrodes of said piezoelectric element, and, when said current is reduced to zero, to open said shunt circuit so as to preclude
the current flow until a voltage between the electrodes of said piezoelectric element subsequently has the extreme value;
and
each of said shunt circuit and said electric circuit is designed to be operated using only a power generated by said piezoelectric
element, wherein said electric circuit includes an extreme-value detection circuit using a peak hold circuit, and a circuit
having a function of selectively opening and closing said shunt circuit in response to an output of said extreme-value detection
circuit.
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