Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Wireless power transfer wikipedia , lookup
History of electric power transmission wikipedia , lookup
Buck converter wikipedia , lookup
Voltage optimisation wikipedia , lookup
Transmission line loudspeaker wikipedia , lookup
Opto-isolator wikipedia , lookup
Mains electricity wikipedia , lookup
Power engineering wikipedia , lookup
Alternating current wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Low frequency acoustic energy harvester and the interface circuit Bin Li and Jeong Ho You Energy Harvesting Materials Lab Department of Mechanical Engineering Southern Methodist University 1 Objective: harvesting wasted acoustic energy (1)Abundant, clean and renewable (2)Intensive in urban life (2)Currently wasted (3)Low energy density Various sound sources 2 Approach Develop an acoustic energy harvester: • Low audible operating frequency(about 100~200Hz) • High efficiency Accumulated acoustic energy Quarter wavelength resonator Vibration to electricity Piezoelectric cantilevered plate AC/DC conversion External circuit 3 Multiple piezo plates placed along the resonator Total output voltage and power as a function of incident SPL The number of plates to generate the maximum voltage SPL: 100dB The summation of power: and power is limited by the interruption of air particle motion. 4 Interface AC/DC conversion circuit design Piezo plates Electric power Pe flowing into the circuit Pe=Ieq×Vp Standard circuit Time Pe=Ieq×Vp Self-powered P- SSHI circuit Time Self-powered SSHI allow more electric power flowing into the circuit and improve AC/DC conversion efficiency by switching technology. 5 Harvested powers in our acoustic energy harvester Incident SPL: 112 dB Conclusions: • Acoustic energy harvesting mechanism is developed at low operating frequency (100~200 Hz) using quarter-wavelength straight-tube resonator with multiple piezoelectric cantilever plates; • The number of plates to generate the maximum voltage and power are limited by the interruption of acoustic air particle motion caused by the presence of plates; • When the incident SPL is 112 dB, the simulated output power of the acoustic energy 6 harvester is 2.9813mW using self-powered P-SSHI circuit.