公开(公告)号：US5099386A

公开(公告)日：1992-03-24

申请号：US698867

申请日：1991-05-13

申请人： Brian P. Stokes ,  Pierre Brosens ,  Stephen O'Dea ,  Albert K. Bukys ,  Steven M. Burgarella ,  Jean I. Montagu

发明人： Brian P. Stokes ,  Pierre Brosens ,  Stephen O'Dea ,  Albert K. Bukys ,  Steven M. Burgarella ,  Jean I. Montagu

IPC分类号： G01R27/26 ,  H01G5/013 ,  H01G5/06

CPC分类号： H01G5/0138

摘要： A variable-capacitance transducer detects the angular position of a rotatable member. The transducer includes a first capacitance plate having a plurality of electrically conductive capacitance electrodes, a second capacitance plate spaced therefrom, and a dielectric element located between the plates. At least two of the electrodes are interconnected by a conductive trace. The dielectric element or one of the plates is fixedly mounted on the rotatable member. The electrodes on the first capacitance plate, in conjunction with the second capacitance plate, form a plurality of capacitances that vary as the angular position of the rotatable member changes. A conductive guard partially envelopes the conductive trace and a conductive guard partially envelopes the electrodes on the first capacitive plate. A spacer defines the distance between the capacitance plates and has a coefficient of thermal expansion and dimensions that cause the distance between the capacitance plates to vary by an amount calculated to compensate for changes in plate area with temperature. The transducer includes a parasitic capacitor plate having a position that is adjustable to compensate for parasitic capacitance. An electromagnetic shield is constructed and positioned, with respect to a driver that controls the rotatable member, such that the shield tends to prevent electromagnetic radiation from the driver from affecting the capacitances between the capacitance plates.

摘要翻译： 可变电容换能器检测可旋转构件的角位置。 换能器包括具有多个导电电容电极的第一电容板，与其间隔开的第二电容板和位于板之间的介电元件。 至少两个电极通过导电迹线相互连接。 电介质元件或其中一个板固定地安装在可旋转构件上。 第一电容板上的电极与第二电容板一起形成随着可旋转构件的角位置变化而变化的多个电容。 导电保护件部分地包封导电迹线，并且导电保护部分地包围第一电容板上的电极。 间隔件限定了电容板之间的距离，并且具有导致电容板之间的距离变化的量的热膨胀系数和尺寸，以补偿板面积随温度的变化。 换能器包括一个寄生电容器板，其具有可调节的位置以补偿寄生电容。 相对于控制可旋转构件的驱动器构造和定位电磁屏蔽，使得屏蔽件倾向于防止来自驱动器的电磁辐射影响电容板之间的电容。