| 摘要 |
There is disclosed herein a wind direction indicator in which an improved weather vane incorporating an elongated airfoil-shaped member for providing the weather vaning is coupled to a potentiometer enclosed in a housing. The potentiometer is coupled to an indicating means that provides a visual display. Mechanically, the weather vane coupling to the potentiometer is within a cavity of the housing that is utilized also as an oil reservoir for lubricating the shaft of the weather vane and the potentiometer so that free rotation thereof may be obtained over extended periods of operation without servicing. The indicating means has two modes of operation on the display device for providing both a high scale and a low scale. That is, when the invention is utilized in boat applications for indicating the direction of the wind relative to, for example, the centerline of the boat extending from the bow to the stern when sailing off the wind the relative wind can have comparatively high-angular relationship to the centerline of the boat and consequently the display device indicates with comparatively large increments the large angular displacements. In the second mode of operation for a sailboat when running close hauled, the angle of the relative wind is comparatively more important and generally the angle will be in a range of between 20 DEG and 50 DEG from the centerline. Consequently, in the second mode of operation the 20 DEG to 50 DEG range of angles of relative wind is expanded to cover the full range of the display device for indicating such angles with comparatively small increments. Signal-damping means are also included so that short time duration wind changes will not provide excessive signal variations in the display device.
|
