Inductance Displacement Sensor Driven by Square Wave Using a New Structure of Multi-segment Coil Without Iron Core
Feng Ping · Jiliang xuebao · 2002
There are some problems in traditional differential transformer type inductance displacement sensor, such as greater inertia of the iron core, narrow linear range, complicate circuits for sine wave generating and signal picking up, etc. To improve this situation, a new inductance sensor for displacement measuring is presented. It has one measuring coil with multiple taps which is driven by square wave, and has a light metal sliding ring for detecting displacement. Unlike traditional sensors, it has no iron core to reduce the inertia. The signals from the taps of the coil are converted to a displacement sensitive signal by a simple amplifier circuit. With this converted signal, the displacement to be measured can be evaluated. Furthermore, to keep the evaluated result from temperature effect, a simple and efficient temperature compensation method is designed. The experimental result shows that the sensor's property is excellent.