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Title: Improvement of force factor of magnetostrictive vibration power generator for high efficiency

Abstract

We develop high power magnetostrictive vibration power generator for battery-free wireless electronics. The generator is based on a cantilever of parallel beam structure consisting of coil-wound Galfenol and stainless plates with permanent magnet for bias. Oscillating force exerted on the tip bends the cantilever in vibration yields stress variation of Galfenol plate, which causes flux variation and generates voltage on coil due to the law of induction. This generator has advantages over conventional, such as piezoelectric or moving magnet types, in the point of high efficiency, highly robust, and low electrical impedance. Our concern is the improvement of energy conversion efficiency dependent on the dimension. Especially, force factor, the conversion ratio of the electromotive force (voltage) on the tip velocity in vibration, has an important role in energy conversion process. First, the theoretical value of the force factor is formulated and then the validity was verified by experiments, where we compare four types of prototype with parameters of the dimension using 7.0 × 1.5 × 50 mm beams of Galfenol with 1606-turn wound coil. In addition, the energy conversion efficiency of the prototypes depending on load resistance was measured. The most efficient prototype exhibits the maximum instantaneous power of 0.73 W and energy ofmore » 4.7 mJ at a free vibration of frequency of 202 Hz in the case of applied force is 25 N. Further, it was found that energy conversion efficiency depends not only on the force factor but also on the damping (mechanical loss) of the vibration.« less

Authors:
; ;  [1]
  1. Kanazawa University, Kakuma-machi, Kanazawa-city, Ishikawa 920-1164 (Japan)
Publication Date:
OSTI Identifier:
22409958
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COMPARATIVE EVALUATIONS; CONVERSION RATIO; DAMPING; ELECTRIC POTENTIAL; ELECTROMOTIVE FORCE; ENERGY CONVERSION; IMPEDANCE; INDUCTION; MAGNETOSTRICTION; PERMANENT MAGNETS; PIEZOELECTRICITY; PLATES; STAINLESS STEELS; STRESSES; VARIATIONS

Citation Formats

Kita, Shota, E-mail: happiest3.7@gmail.com, Ueno, Toshiyuki, and Yamada, Sotoshi. Improvement of force factor of magnetostrictive vibration power generator for high efficiency. United States: N. p., 2015. Web. doi:10.1063/1.4907237.
Kita, Shota, E-mail: happiest3.7@gmail.com, Ueno, Toshiyuki, & Yamada, Sotoshi. Improvement of force factor of magnetostrictive vibration power generator for high efficiency. United States. doi:10.1063/1.4907237.
Kita, Shota, E-mail: happiest3.7@gmail.com, Ueno, Toshiyuki, and Yamada, Sotoshi. Thu . "Improvement of force factor of magnetostrictive vibration power generator for high efficiency". United States. doi:10.1063/1.4907237.
@article{osti_22409958,
title = {Improvement of force factor of magnetostrictive vibration power generator for high efficiency},
author = {Kita, Shota, E-mail: happiest3.7@gmail.com and Ueno, Toshiyuki and Yamada, Sotoshi},
abstractNote = {We develop high power magnetostrictive vibration power generator for battery-free wireless electronics. The generator is based on a cantilever of parallel beam structure consisting of coil-wound Galfenol and stainless plates with permanent magnet for bias. Oscillating force exerted on the tip bends the cantilever in vibration yields stress variation of Galfenol plate, which causes flux variation and generates voltage on coil due to the law of induction. This generator has advantages over conventional, such as piezoelectric or moving magnet types, in the point of high efficiency, highly robust, and low electrical impedance. Our concern is the improvement of energy conversion efficiency dependent on the dimension. Especially, force factor, the conversion ratio of the electromotive force (voltage) on the tip velocity in vibration, has an important role in energy conversion process. First, the theoretical value of the force factor is formulated and then the validity was verified by experiments, where we compare four types of prototype with parameters of the dimension using 7.0 × 1.5 × 50 mm beams of Galfenol with 1606-turn wound coil. In addition, the energy conversion efficiency of the prototypes depending on load resistance was measured. The most efficient prototype exhibits the maximum instantaneous power of 0.73 W and energy of 4.7 mJ at a free vibration of frequency of 202 Hz in the case of applied force is 25 N. Further, it was found that energy conversion efficiency depends not only on the force factor but also on the damping (mechanical loss) of the vibration.},
doi = {10.1063/1.4907237},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 17,
volume = 117,
place = {United States},
year = {2015},
month = {5}
}