Abstract: To provide a gyro compass for the use of a high speed ship, in a gyro compass of the type having north-seeking means which is applied to support a gyro sphere or gyro case immersed in a liquid in a tank, a substantially first-order lag filter is provided in an azimuth follow-up loop or a damping loop, the substantially first-order lag filter having a time constant T.sub.F which is approximately equal to a ratio C/k.sub.T of the viscosity torque coefficient C to the twisting torque coefficient k.sub.T of the torque produced between the tank and the gyro case. A speed error correcting means has a substantially first-order lag filter having a time constant which is approximately equal to that of the north-seeking means, and is applied to correct the output of azimuth indicator by a speed error correcting angle through the substantially first-order lag filter.

Abstract: A gyro compass having a gyro case housing therein a gyro whose spin axis is held substantially in the horizontal plane, a supporting device for supporting the gyro case with freedom of three axes and means for applying a torque proportional to an inclined angle of the gyro spin axis relative to the horizontal plane around a vertical axis of the gyro case perpendicular to the spin axis is disclosed in which there are provided a detecting device for detecting an inclination angle of the spin axis relative to said horizontal plane, torquer for applying a torque to the gyro case about its vertical axis, and an acceleration error controlling device for receiving an output signal from the detecting means and for controlling the torquer such that the torquer produces a predetermined torque to be applied to the gyro case about its vertical axis.

Abstract: A magnetic sensor including an annular iron core, an annular hollow bobbin for a primary winding which incorporates therein the annular iron core, the bobbin having a plurality of protruded portions which are arranged along a circumference of the annular bobbin with an equal distance, each of the protruded portions being extended in a direction parallel to a center axis of the annular iron core, the primary winding being wound on the annular bobbin at respective portions between adjacent protruded portions with an equal number of turns, a bobbin for a secondary winding having a positioning means for the primary winding in association with the protruded portions of the bobbin for the primary winding when the bobbins for the primary and secondary windings are assembled, the secondary winding being wound on the bobbin to form more than two pairs of winding groups.

Abstract: A vibration-type gyro apparatus is disclosed, which includes a vibration mass portion, a piezo-electric element for detecting the displacement of the apparatus and a preamplifier having an input resistance R and supplied with the output from the piezo-electric element, wherein the input resistance R is selected to have a value substantially expressed as R.apprxeq.1/C.omega. (where C is an electrostatic capacity of the piezo-electric element and .omega. is a vibration angular velocity of the mass portion) so that the gyro apparatus will be substantially free of variations due to temperature changes.

Abstract: A gyrocompass having a gyro rotor, and a device for applying to the gyro rotor about its vertical axis a torque in proportion to an inclination angle of the spin axis of the gyro rotor from a horizontal plane so as to attenuate the north-seeking action of the gyro rotor, in which the torque is controlled to be proportional to the inclination angle for its component which varies with a period same or close to that of the north-seeking action while to be approximately zero for a component of the inclination angle which does not vary.