基于 51 单片机的金属探测器摘 要本文着重介绍了一种基于 AT89S52 单片机控制的智能型金属探测器的硬件组成、软件设计、工作原理及主要功能。该金属探测器以 AT89S52 单片机为核心，采纳线性霍尔元件 UGN3503 作为传感器，来感应金属涡流效应引起的通电线圈磁场的变化，并将磁场变化转化为电压的变化，单片机测得电压值，并与设定的电压基准值相比较后，决定是否探测到金属。系统软件采纳汇编语言编写。在软件设计中，采纳了数字滤波技术消除干扰，提高了探测器的抗干扰能力，确保了系统的准确性。此外，文中还对影响金属探测器的灵敏度与稳定性的因素进行了探讨，认为仪器的工作频率、检测线圈的尺寸及匝数等是影响灵敏度的主要因素;而应用现场的环境温度、湿度及线圈的制作工艺和供电电源的稳定程度是仪器稳定性的影响因素。关键词：单片机，金属探测器，线性霍尔元件，电磁感应，灵敏度ABSTRCT This paper describes the composition of hardware and software,working principles and the functions of an intelligent metal detector which mainly consists of AT89S52 Single-Chip Microcomputer and linear Hall-Effect Sensor. The equipment adopts UGN3503U linear hall-effect sensor as probe to detect the magnetic field change of the centre of a search coil resulted from eddy current effect and turn this magnetic field change into voltage change.The Single-Chip Microcomputer measures the peak value of voltage and compares it with reference voltage.Then determine whether detect metel or not.In case of detection of a metallic mass,the Metal Detector porvides an acoustical and optical alarm.The systems software adopts the assmbler language to be written.Inside the software,the digital filter technology is utilized to eliminate the jamming.So the stability of system and measuring veracity are improved.The effect of all factors on sensitivity and stability of Metel Detetor are discussed in this paper.It is concluded that the operating frequency,the size of the search coil and turns ...
