Resonant Electro-Mechanical Coupling – A Possible Renewable Energy Source
Abstract
This paper looks at a simple Electro-Mechanical System that is tuned to resonate with both mechanical and electrical resonance. The intention is to couple the system resonance such that the amplitude of the output voltage is increased. The basic setup consists of a forced Mass-Spring System consisting of a speaker driving a mass attached to a tension-spring. The mass is a Neodymium cylindrical magnet. The vertically driven system couples to a magnet coil which sits over the magnet. Thus, by induction a voltage is generated within the coil. The coil is connected in series with a set of electrolytic capacitors. The resulting Resistor-Capacitor-Inductor (RCL) circuit is so designed as to resonate. The idea behind this coupling is to increase the output voltage of the circuit, thereby creating a voltage supply that could be boosted via transformer action, if necessary. Noting that the resulting circuit provides a source of single-phase electricity, such a setup could be used to charge small electronic devices like cellphones and mobile earphone sets. Mechanical resonance is indicated by the erratic vibration of the speaker, spring and magnet system. Knowing the magnet mass and measured resonant frequency the approximate spring constant can be calculated. The resonant frequency is then used as the driving frequency for the electrical circuit consisting of the RCL components. Noting the electric circuit resonance frequency, the approximate capacitance needed can be calculated using the driving frequency and the inductance of the said magnet coil. Using the circuit capacitance and appropriate circuit resistance, the maximised quality factor is sought, therefore the objective of the electric circuit design is to maximise the output voltage. The power generated by the device was found to be less than ~1 W. This system can be optimized to deliver maximum power output at the required resonant frequency, by greatly increasing the coil turns, using closer tolerances between the moving magnet and the wound coil and/or using materials that would ensure added magnetic coupling. Such a system can be used as a possible source of renewable energy especially on reciprocating engines, where exciting forces are available.
Article Views and Downloands Counter
References
Caldwell, N. B. (2016). Exploiting the principal parametric resonance of an RLC “Circuit for vibratory energy harvesting”. Clemson University Maters Thesis. All Theses. 3041. https://tigerprints.clemson.edu/all_theses/3041.
Chiu, M. C., Chang, Y. C., Yeh, Y. J. & Chung, C. H., (2016). Numerical assessment of a one-mass spring-based electromagnetic energy harvester on a vibrating object, Archives of Acoustics, Vol. 41, No. 1, pp. 119–131 (2016). DOI:10.1515/aoa-2016-0012
French, A. P. (1996). Vibrations and waves. The M.I.T. Introductory Physics Series. Chapman & Hall. London.
Georgia State University (GSU). (2023). Resonance and series resonance. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/serres.html.
Gieras, J. F., Oh, J. H., & Huzmezan, M. (2008). Electromechanical portable energy harvesting device: Analysis and experimental tests. Elektrotechnika 13, 17-36.
Griffiths, D. J. (1999). Introduction to Electrodynamics. 3rd Edition. Prentice Hall, New Jersey.
Halliday, A. H., Resnick, A. H. & Walker, A. H. (2003). Fundamentals of Physics, Volume 2 Extended. Enhanced Problems Version, 6th Edition. McGraw-Hill, London.
Hasan, M. H., Alsaleem, F. M., Jaber, N., Hafiz, M. A. A, & Younis, M. I. (2018). Simultaneous mechanical and electrical resonance drive for large signal amplification of micro-sensors. AIP Advances,015312https://dio.org/10.1063/1. 5018321.
Hayt, W.H. and Kemmerly, J.E. (1978). Engineering circuit analysis. 3rd Edition. McGraw- Hill International Book Company.
Hossein, P., M. & Morris, E.J. (2006). Electrodynamics of a magnet moving through a conducting Pipe. arXiv:physics/0406085 [physics.class-ph], . Can. J. Phys. 84, 253 https://doi.org/10.48550/arXiv.physics/0406085
Inman, D. J. (2001). Engineering vibration. 2nd Edition. Prentice Hall, Inc. New Jersey.
Kraftmakher, Y. (2000). Eddy currents: Contactless measurement of electrical resistivity. Am. J. Phys. 68 (4), April 2000.
Meirovitch, L. (1986). Elements of vibration analysis. 2nd Edition. McGraw-Hill Book Company. New York.
Mohanty, A., Parida, S., Behera, R. K., & Roy, T. (2019). Vibration energy harvesting: A review, Journal of Advanced Dielectrics, Vol. 9, No. 4 (2019). DOI 10.1142S2010135X19300019.
Muscat, A., Bhattacharya, S. & Zhou, Y. (2022). Electromagnetic vibrational energy harvesters: A review, Sensors, 22, 5555. https//doi.org/10.3390/s22155555.
Nasar, S. A. (1981). Schaum’s outline of electric machines and electromechanics. Theory and Problems. McGraw-Hill, New York.
Tesla Research. (2023). Inventions and Experiments of Nikola Tesla.https://teslaresearch. Jimdofree.com/oscilators/mechanical-oscilator/.
Timoshenko, S. P., Young, D. H. & Weaver, W. (1974). Vibration Problems in Engineering. 4th Edition. John Wiley & Sons. New York.
University of Alberta. (2023). Forced vibrations of damped single-degree of freedom systems. https://engcourses-uofa.ca/books/vibrations-and-sound/forced-vibrations-of-damped-single-degree-of-freedom-systems/base-excitation-in-a- damped-system/.
Copyright (c) 2024 Africa Journal of Technical and Vocational Education and Training
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Copyright Notice Copyright of published articles is held by AfriTVET. No limitation will be placed on the personal freedom of authors to copy or to use in subsequent work, material contained in their papers. Please contact the Publisher for clarification if you are unsure of the use of copyright material. Apart from fair dealing for the purposes of research and private study, or criticism and or review, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the Publishers.
