Sound to electric energy generating device

This paper presents the potential of an electromagnetic transducer device in a form of audio speaker that is used to capture sound waves to be converted into electricity. It is an interesting concept but less explored by researchers. The objective of the study is to measure the potential of electromagnetic transducer as a way to generate electricity. It deals with the creation of electricity through movement and magnetism. Sound waves can induce movement on the surface which in turn moves the transducer thus creating electricity. The source of sound was coming from an 8-inch subwoofer speaker with a frequency of 80 Hz that was held constant throughout the experiment. Furthermore, using simple linear regression analysis, the study showed that for every linear increase of sound intensity level and distance of the source, there is an exponential increase and an exponential decrease in the voltage root mean square (RMS) respectively. The functionality assessment of the device was statistically analyzed using completely randomized design. It was found that the energy level significantly increased as the sound intensity level increases given a fixed distance of 15 mm from the source. The device could generate enough energy to power small electronics such as light emitting diodes (LED), transistor and resistor.

Tuning of a shunted electromagnetic vibration absorber based on the maximisation of the electrical power dissipated

This paper investigates a local tuning approach for a shunted electromagnetic vibration absorber, which is based on the maximisation of the electrical power dissipated by the coil and shunt components. The study considers a simplified problem with a single-degree-of-freedom mechanical hosting system, which is excited by a white noise stochastic force. The hosting system is equipped with a coil-magnet seismic transducer, which is connected to a resistive-inductive shunt. The study examines the effectiveness of the shunted electromagnetic vibration absorber with respect to the following cost functions. Firstly, the reference cost function, which is based on the minimisation of the time-averaged kinetic energy of the hosting system. Secondly, the local cost functions, which are based on: the maximisation of the time-averaged vibration power absorbed by the shunted electromagnetic vibration absorber; the maximisation of the time-averaged mechanical power dissipated by the electromagnetic transducer and the maximisation of the time-averaged electrical power dissipated by the coil and the shunt. The study shows that, provided the transducer is lightly damped, the local cost function based on the maximisation of the electrical power dissipated by the coil and the shunt gives the same optimal tuning parameters than the reference cost function. Therefore, provided the electromagnetic transducer is properly designed, the shunt can be suitably tuned by maximising the time-averaged electrical power dissipated by the coil and shunt. This is a rather appealing practical solution since it can be implemented locally without the need of measuring the response of the hosting system and also it can be implemented in the shunt circuit without the need of extra sensors.

Hardware-in-the-loop Testing of an Electromagnetic Transducer with a Tuned Inerter for Vibratory Energy Harvesting

This paper assesses the vibratory energy harvesting performance of a tuned inertial mass electromagnetic transducer (TIMET) through hardware-in-the-loop (HIL) testing under random vibration. The TIMET has been developed by adding a tuning spring and an extra rotational inertial mass to a conventional electromagnetic transducer (ET) with a motor. The authors have already shown that the energy harvesting efficiency of the TIMET can be increased by taking advantage of the mechanical resonance effect of the rotational inertial mass due to the tuning spring through numerical simulation studies. In addition, further improvement in power generation of the TIMET can be achieved theoretically by controlling the current to the motor based on the appropriately developed algorithms. In this paper, the superiority of the TIMET over the ET under random disturbances when the current to the motor is controlled by the algorithms proposed for the ET in the literature is experimentally verified. Moreover, the accuracy of the numerical simulation using the developed device models is validated by comparing with the test results.

AN AUTONOMOUS LOW-FREQUENCY BROADBAND HYDROACOUSTIC EMITTING STATION

Разработана и изготовлена автономная низкочастотная широкополосная гидроакустическая излучающая станция с электромагнитным преобразователем, развивающая акустическое давление до 2400 Па (188 дБ), приведенное к расстоянию 1 метра от оси излучателя, в диапазоне частот 420–520 Гц (по уровню −3 дБ) и глубиной погружения до 500 м. Примененные технические решения позволяют использовать станцию для широкого круга океанологических исследований, а также при построении систем навигации подводных аппаратов и передачи данных по гидроакустическому каналу. An autonomous low-frequency broadband hydroacoustic emitting station with electromagnetic transducer has been developed and manufactured, for developing acoustic pressure up to 2400 Pa (188 dB) measured a distance of 1 meter from the axis of the emitter in the frequency range 420–520 Hz (at −3 dB level) and immersion depth up to 500 m. The applied technical solutions allow to use the station for a wide range of oceanographic studies, as well as when construction of navigation systems for underwater vehicles and data transmission on the hydroacoustic channel.

Experimental characterization and performance improvement evaluation of an electromagnetic transducer utilizing a tuned inerter

This research reports on the experimental verification of an enhanced energy conversion device utilizing a tuned inerter called a tuned inertial mass electromagnetic transducer (TIMET). The TIMET consists of a motor, a rotational mass, and a tuning spring. The motor and the rotational mass are connected to a ball screw and the tuning spring interfaced to the ball screw is connected to the vibrating structure. Thus, vibration energy of the structure is absorbed as electrical energy by the motor. Moreover, the amplified inertial mass can be realized by rotating relatively small physical masses. Therefore, by designing the tuning spring stiffness and the inertial mass appropriately, the motor can rotate more effectively due to the resonance effect, leading to more effective energy generation. The authors designed a prototype of the TIMET and conducted tests to validate the effectiveness of the tuned inerter for electromagnetic transducers. Through excitation tests, the property of the hysteresis loops produced by the TIMET is investigated. Then a reliable analytical model is developed employing a curve fitting technique to simulate the behavior of the TIMET and to assess the power generation accurately. In addition, numerical simulation studies on a structure subjected to a seismic loading employing the developed model are conducted to show the advantages of the TIMET over a traditional electromagnetic transducer in both vibration suppression capability and energy harvesting efficiency.