简易电子秤的系统设计

介绍了在四片应变电阻片组成的全桥电阻桥电路的基础上实现较高精度简易电子称的过程。四片常用120Ω精密铂金应变电阻片组成全桥电阻桥电路,通过调零电路、前级放大、低通滤波、后级精密放大、AD采样,实现简易电子称的基本功能。论述了实现对悬梁臂的形变检测,对微小信号实现放大。系统通过低通滤波器以及零漂移,自调零放大器实现对噪声的抑制,以及对有用信号的放大与检测。

This paper discusses the process of realizing the quite high-precision simple electronic scale on the basis of the four pieces of high strain resistance composed of full bridge electric bridge circuitResistance bridge is made up of four universal 120Ω precise resistance strain gauge.By go through zeroing circuit,pre-amplifier,lowpass circuit,post-ampiifier,AD sampling circuit,realizing the basic functionality of simple electronic scale.This paper discusses how to detect the distortion of cantilever,and how to amplify the small signal.