The Design of Operational Amplifier for Low Voltage and Low Current Sound Energy Harvesting System

Malaysian Technical Universities Conference on Engineering and Technology 2017

Fang, Liew Hui^1 ; Abd Rahim, Rosemizi Bin^2 ; Isa, Muzamir^1 ; Syed Hassan, Syed Idris^1 ; Ismail, Baharuddin Bin^3

School of Electrical System Engineering, University Malaysia Perlis, Pauh Putra Campus, Perlis, Arau, Malaysia^1

School of Computer and Communication Engineering, University Malaysia Perlis, Pauh Putra Campus, Perlis, Arau, Malaysia^2

Center of Excellence for Renewable Energy (CERE), Universiti Malaysia Perlis, Pauh Putra Campus, Perlis, Arau, Malaysia^3

关键词: Alternate currents;    Direct current power;    Electrical energy;    Low-power devices;    Measured results;    Operational amplifier (op amp);    Parallel connections;    Power output efficiencies;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/318/1/012035/pdf
DOI  :  10.1088/1757-899X/318/1/012035

来源: IOP

【 摘 要 】

The objective of this paper is to design a combination of an operational amplifier (op-amp) with a rectifier used in an alternate current (ac) to direct current (dc) power conversion. The op-amp was designed to specifically work at low voltage and low current for a sound energy harvesting system. The goal of the op-amp design with adjustable gain was to control output voltage based on the objectives of the experiment conducted. The op-amp was designed for minimum power dissipation performance, with the means of increasing the output current when receiving a large amount of load. The harvesting circuits which designed further improved the power output efficiency by shortening the fully charged time needed by a supercapacitor bank. It can fulfil the long-time power demands for low power device. Typically, a small amount of energy sources were converted to electricity and stored in the supercapacitor bank, which was built by 10 pieces of capacitors with 0.22 F each, arranged in parallel connection. The highest capacitance was chosen based on the characteristic that have the longest discharging time to support the applications of a supercapacitor bank. Testing results show that the op-amp can boost the low input ac voltage (∼3.89 V) to high output dc voltage (5.0 V) with output current of 30 mA and stored the electrical energy in a big supercapacitor bank having a total of 2.2 F, effectively. The measured results agree well with the calculated results.