| The technology of power generator based on micro-scale vibration has been a hot in the world.The power generator which converts the vibrational energy into electrical energy has a long usetime theoretically. Thus,the design of this power generator not only has important theoretical significance,but also extensive application demand.In this paper, present situation and development of power generator based on micro-scale vibration were analyzed. Emphasis is laid on the mechanism,equipment and performance of electret film micro-scale vibration power generator under the micro bration environment. According to static induction and the performance of electret film in storing electrical charge,the program of power generator based on micro-scale vibration by using electret film was proposed. When electret film is connected to electrode, there will be induced charge in the electrode,and once another vibrating plate used as another electrode is put right above the film, induced charge will also be found on the plate. Thus, this two eletrodes make a capacitor. When distance of the two plates changes by the environmental vibration, the capacitance of the capacitor will change, companying with charge transfer and output voltage of the whole device can be detected. After rectifier and filter, stable DC output voltage can be obtained,and the goal of power supply is achieved. There three requirements have to be met when using this kind of power generator:(1) sustained vibration,(2)the vibration frequency only can change in a certain range,(3)the plate of the device should have even mass distribution.The output voltage of this device is influenced by the surface potential of electret, vibration frequency and amplitude of plate,and its load.In this research, electret film is(8.9mm in diameter,12.5μm in thickenss)was charged by negative corona charging method. When the vibration frequency is in the range of 20Hz and 100Hz,the AC output voltage can reach 407mV. In order to increase the output voltage,the device was made integrated, and each power unit was added with rectifier and filter for the purpose of avoiding phase influence. Comparisons were made among the values of output voltage from two units in series, five units in series and ten units in series respectively. Results showed that the largest output voltage can reach 4658mV,which was almost 12 times as much as that of the per generator unit. In order to gain much higher output current, five generator units in series were made into a set, then made the two sets to for sets in parallel. Using this integrated device, output voltage can reach to 2.0V after 20 minutes of charging for the electrolytic capacitor,and LED can be lighted. As a result, large-scale integration can improve the power of electret film micro-scale vibration power generator. In this way, the transformation from vibrational energies to electrical energies is achieved. The power generation in this method features simple structure,low cost,and is environment-friendly. Thus,it deserves high research values and wide application prospect. |
