基于恒流源向电感充放电的LVDT设计

针对目前工业测试场合中所用到线性可变差动变压器(LVDT)系统结构与电路组成较复杂,且线性度与灵敏度不高等因素;设计出了一款空心LVDT,用直流恒流源作为其激励信号,由ARM单片机控制开关桥向原线圈充放电,在稳定放电期间,利用单片机的控制逻辑去捕获两个副线圈上的脉冲高度差来进行位移量的测量;最终试验数据表明,该方法所设计的空心LVDT在满量程为3 mm时,相对百分比精度可达0.3%,灵敏度为0.284字/μm,且有较高的频率响应特性,能满足一般的工业自动控制与测量需求。

Design of LVDT based on constant current source charging or discharging to inductor

Be aimed at the complex of the system structure and the circuit composition, and the low linearity and sensitivity of LVDT used in industrial testing, design a hollow LVDT, use the DC constant current as its excitation signal, and the ARM microcontroller controls the switch bridge to charge or discharge the original coil. During the stable discharge period, the microcontroller control logic is used to capture the pulse height difference between the two secondary coils to measure the displacement. The final test data show that the full scale of the hollow LVDT designed by this method is 3 mm. The relative percentage accuracy is 0.3%, the sensitivity is 0.284 words/μm, and the high frequency response characteristic, which can meet the general industrial automatic control and measurement requirements.