作者：刘博隽¹, 孙彪², 张甫², 唐求², 张建文³

作者单位：1. 湖南师范大学物理与信息科学学院, 湖南 长沙 410006;
2. 湖南大学电气与信息工程学院, 湖南 长沙 410082;
3. 国网新疆电力公司电力科学研究院, 新疆 乌鲁木齐 830011

关键词：程控精密恒流源;单T选频网络;改进型Howland电流泵;生物电阻抗谱

摘要：

针对生物电阻抗谱测量需求，设计一款频率可程控调节的精密恒流源，给出频率可调程控精密恒流源的构成框图，并详细介绍基于单T选频网络的信号源电路设计和基于改进型Howland电流泵的电压电流转换电路设计。仿真实验表明：程控精密恒流源在200~500 kHz频率范围、10 ~1 k的负载范围下的电流波动在1.63%以内。电路频率调节便捷、输出阻抗高、负载能力强、输出电流稳定，已应用于肉类水分快速测定仪和注水肉快速测量仪。

Design of programmable constant current source with adjustable frequency

LIU Bojun¹, SUN Biao², ZHANG Fu², TANG Qiu², ZHANG Jianwen³

1. College of Physics and Information Science, Hu'nan Normal University, Changsha 410006, China;
2. College of Electrical and Information Engineering, Hu'nan University, Changsha 410082, China;
3. State Grid Electric Power Research Institute of Xinjiang Electric Power Company, Urumqi 830011, China

Abstract: Aiming at the demand of bioelectrical impedance spectroscopy, a precision constant current source with programmable frequency adjustment was designed, and the block diagram of this constant current source was given. The design of signal source circuit based on single T frequency selective network and the design of voltage-to-current (VTC) converter circuit based on improved Howland current pump were both introduced in detail in this paper. According to the simulation results, the current fluctuation of the programmable precision constant current source in the frequency range of 200-500 kHz and the load range of 10 Ω-1 kΩ is less than 1.63%. With the convenience of frequency adjustment, the high output impedance, the strong load capacity and the stable output current, this circuit has been applied to rapid meat moisture analyzer and rapid water-injected meat measurement instrument.

Keywords: programmable constant current source;single T frequency selective network;improved Howland current pump;bioelectrical impedance spectroscopy

2018, 44(8): 91-96  收稿日期: 2017-09-10;收到修改稿日期: 2017-11-15

基金项目: 

作者简介: 刘博隽(1996-),男,湖南怀化市人,专业方向为物理学

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