Abstract:
A sensor for providing an indication of the movement of one component of a system with respect to another includes a plurality of discrete electrodes and a common electrode affixed to the non-moving component along the axis of movement of the moving component and a pointer affixed to the moving component also along the axis of movement. As the moving component moves, it positions the pointer at consecutive ones of the plurality of discrete electrodes forming a capacitor structure with each in succession. When interrogated, the capacitor provides a signal indicative of the position of the moving component. The sensor is useful for indicating linear movement, angular displacement and pressure, strain and temperature when adapted to structures which indicate such parameters as a function of displacement. Alternative structures include "Bar Codes" with a laser as a pointer and magnetic stripes with a magnetic read head as the pointer. The output of the sensor may be employed as a feedback signal to a position controller for, for example, a computer-driven machine tool or for a digital hydraulic control system.