| 摘要 |
PURPOSE:To enable the expansion of the maximum detectable azimuth, by providing a plurality of vibrators vertical to the azimuth to be detected and another vibrator on the horizontal line containing the midpoints between the centers of the vibrators. CONSTITUTION:The top surfaces 6a-6c of vibrators 1a-1c having sensor bodies 8a-8c are arranged within the same plane in such a manner that the vibrators 1b and 1c are set vertical to the azimuth to be detected while the vibrator 1a is set so as to position the center (a) thereof on the horizontal line containing midpoints 0 between the centers (b) and (c) of the vibrators 1b and 1c. Outputs of the vibrators 1a and 1c are fed to amplifiers 2a-2c and a 1/2 phase generation circuit 3 generates a voltage according to the phase on the azimuth to be detected according to outputs of the amplifiers 2b and 2c. The resulting voltage and the output voltage of the amplifier 2a are subjected to a comparison processing with an azimuth detection circuit 4. In this case, the circuit 4 detects with three gates at what range the phase difference exists in the half cycle of the output of the amplifier 2a depending on to which ON period the rising position of the output voltage of the circuit 3 belongs at the gates to detect the lag or advance of the phase. |
