Development of step-up transformer for low current and low power sound energy harvesting system

摘要

In this paper, an enhanced low power (2.29 mW) and low current (0.588 mA) step-up transformer energy harvester circuit for powering low consumption electrical devices were designed and verified. The objective of this research is to presents a novel method for battery-less circuit start-up from ultra-low voltage energy harvesting sources. The approach proposed for the first time by using a transformer and bridge rectifier as the key component for the step-up harvesting device. The proposed transformer circuit is first modeled and then experimentally verified with a sound energy harvesting system. Based on several experiments carried out in laboratory and results presented show that the proposed step-up transformer topology begins to operate at 3.89 V and achieves a 5.0 V output voltage at low frequency that is 68 Hz. This work transformer design construction needs no inductive component, not have SMT microelectronics technology. It is also have benefits of simple and achieves self-starting operation with a smaller input voltage, simple circuits and save cost. The measured results agree well or comparable with the theoretical results. From the result, it shows that the vibration of sound energy generates from speaker strike impact produce mechanical energy convert into electrical energy. The PZT-5A harvest energy effectively through transformer and provide energy to utilize low power devices such as wireless sensor network or ultra-low power sensor.