【作者】 高宗海； 王月娥； 李大成； 马科研；

【Author】 GAO Zong-hai, WANG Yue-e, LI Da-cheng, MA Ke-yan (Modern Science and Sensor Research Laboratory; Xi’an University of Technology)

【机构】 西安理工大学现代科学仪器与传感器研究室；

【摘要】 采用取样电阻将交流微电流转换成微伏级的电压,通过电路调制为10KHz的信号,将电压进行放大．实验中用CA3140组成具有带通滤波放大功能的电路,对微伏级的电压信号进行放大,此带通滤波放大电路的中心频率是10KHz．放大后通过相敏检波电路和低通滤波器去掉载波信号得到放大后的被测信号, 其中相敏检波电路的频率和载波的频率—致．整个电路系统精度能达到1．6％．更多还原

【Abstract】 A new measurement method of micro-AC is presented in the paper. BPF (band- pass filter ) and demodulator is designed to magnify the AC . The voltage signal is modulated to 10KHz and magnified 160000 times through BPF in the circuit The demodulator is carried out through RC circuit, the charge and discharge time of which is controlled by analog switch. Through experiments, the measurement precision reach to 1.6% FS and the data measured show that the design is feasible更多还原