石英晶片参数测量的物理实验教学系统

石英晶片是最重要的电子元件,其物理参数的测量直接影响电子产品的质量。本文考虑实际气隙的影响,建立了石英晶片的等效电路模型;推导了气隙对测量误差影响公式,作为误差的主要补偿依据;设计物理参数测量的π型网络,使用直接数字频率合成器作为激励信号源,通过测量石英晶片在π网络中的电流响应,获得其谐振频率、相对活力、杂波系数等多种物理参数。采用ISA总线接口作为上位机与控制器的通信接口,采用微控制器AT89C52作为控制单元,利用多线程技术在VisualC++平台上开发了上位机软件来进行数据处理和逻辑控制。经实际运行表明,该系统测量精度和功能等系统指标达到同类系统标准,已作为电子学科的实验教学系统。

A Physics Experiment Teaching System for Quartz Crystal Parameter Measurements

Quartz Crystal(QC) is the foremost electronic component,the physical parameter measurement of which has a direct influence on the quality of electronic products.An equivalent circuit model of quartz crystal is established by taking into account the impact of the actual air gap;the formula is derived from the effect of the air gap on the measurement error,which can become the major error compensation basis;and then the physics experiment system for the whole quartz crystal(QC) parameter measurements is developed using the π network.A direct digital synthesizer is acted as the stimulate source,and micro-controller AT89C52 is used as the controll unit.The physical parameters such as the resonate frequency,the relative activity,the spurious coefficient are obtained by the current response measurement of QC in the π network.The ISA bus interface is acted as the communication interface of PC and controller,and data processing and logic control are implemented by the PC software which uses multi-process techniques in the platform of Visual C++.The practical results show it possesses the same precision and performance as the same type of systems,and it has been used as the experimental teaching system of Electronics.