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International Journal of Distributed Sensor Networks
Volume 2012 (2012), Article ID 603709, 6 pages
http://dx.doi.org/10.1155/2012/603709
Research Article

An Energy Supply System for Wireless Sensor Network Nodes

1School of Electronic Information Engineering, Henan University of Science and Technology, Room 48, Xiyuan Road, Jianxi District, Luoyang 471003, China
2Henan Key Laboratory for Machinery Design and Transmission System, Henan University of Science and Technology, Luoyang 471003, China

Received 26 November 2011; Revised 25 March 2012; Accepted 25 March 2012

Academic Editor: Sabah Mohammed

Copyright © 2012 Guoqiang Zheng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The power source is a critical obstacle for wireless sensor network nodes. In order to prolong the lifetime of wireless sensor networks, this paper presents an energy supply system that uses a specially designed broadband piezoelectric energy harvesting technology for sustaining the operation of wireless sensor network nodes. The proposed energy supply circuit can apply an optimal control voltage to the piezoelectric element to ensure impedance matching between the vibration source and the energy supply system in nonresonance frequencies. As compared to the conventional piezoelectric energy harvesting circuit, it is shown that the efficiency has been increased 4 times. In this work, the overall system structure, the function modules design, and the performance testing analysis are illuminated in detail. Experimental results reveal that this energy supply system can significantly improve power within the wide bands by the active piezoelectric energy harvesting technology and enable wireless sensor network nodes to operate normally.