光幕靶用大动态范围信号处理电路设计

Design of large dynamic range signal processing circuit for light screen target

摘要:

为提高光幕靶测速精度和弹径适应范围，设计了一种光幕靶用自动调节增益的对数放大电路，扩大信号处理电路的测试动态范围。论文分析矩形探测光幕和扇形探测光幕两类典型光幕靶式光幕工作原理，分析弹丸过幕信号幅值与弹丸直径和过幕位置之间的关系。依据对数放大电路特性设计了基于TL441芯片的电压型对数放大电路和LOG112芯片的电流型对数放大电路，对设计的电路进行对数放大特性和动态范围进行测试。试验结果表明，设计的信号处理电路的输入输出信号幅值具有对数特性，其动态范围可达31dB，提高了光幕靶的测试动态范围，满足各口径弹丸的速度测量。

Abstract:

In order to improve the accuracy of speed measurement and the adaptive range of projectile diameter, a logarithmic amplifying circuit with automatic gain adjustment is designed to expand the dynamic range of signal processing circuit.This paper analyzes the working principle of two kinds of typical light curtain: rectangular light curtain and fan-shaped light curtain, and analyzes the relationship between the signal amplitude of projectile passing through the curtain, the diameter and position of projectile passing through the curtain. According to the characteristics of the logarithmic amplifying circuit, the voltage-type logarithmic amplifier circuit based on TL441 and the current-type logarithmic amplifier circuit based on LOG112 are designed.The logarithmic amplification characteristic and dynamic range of the designed circuit are tested.The test results show that the input and output signal amplitude of the designed signal processing circuit has logarithmic characteristics, and its dynamic range can reach 31dB, which improves the dynamic range of the light curtain target test, and meets the speed measurement of various caliber projectiles