| 摘要 |
<p>An electrical digital compass for use in a vehicle which includes sensing means (13) for sensing a magnetic field and means (35) for displaying the vehicle's orientation. A compensation and variation correction control, driven by a microprocessor (75), is also included. This acts by correcting the displayed orientation to allow for local magnetic variation and other constant factors such as the distortion of the signal caused by the vehicle itself. The relevant correction factors are stored in the microprocessor by the use of a calibration button (42) when the vehicle is placed first facing due North and then due West. A temperature sensor (90) and display (37) may also be provided.</p> |
