William Edward May John Lawrance Howard Tom S. By delaying the flow of the liquid or by making eccentric the point of action of the control, a damping factor is introduced that converts the ellipse into a spiral so that the gyrocompass eventually settles pointing true north ( see figure). Either will convert the path traced by the axis into an ellipse. The case of the gyroscope is made pendulous, or a liquid is arranged to flow from side to side. To convert it into a gyrocompass, a control must be introduced that, when the axis tilts, will operate to precess (turn) it toward the meridian.
#Magnetic gyroscope free
The axis of a free gyroscope will describe a circle around the pole of the heavens. The direction a gyrocompass points is independent of the magnetic field of the Earth and depends upon the properties of the gyroscope and upon the rotation of the Earth. The relatively slow drift of the directional gyroscope from its heading may be corrected manually from time to time when the airplane is in level and straight flight. By itself, neither is satisfactory as a directional reference, but a combination of the directional gyroscope with a magnetic compass gives the pilot complete and stable directional information. The utility of this instrument may appear to be very limited, but it happens to complement the magnetic compass very well. The gyroscope maintains a specific directional line in space with a possible error caused by drift of two or three degrees in each half hour that the gyroscope is left free.
In one such arrangement, a saturable-inductor compass (so named because of its use of materials that can be readily induced to carry a maximum magnetic flow, or magnetic saturation) is mounted on a gyroscope, but this is not always convenient from the point of view of size and weight.Īnother system has a means of comparison between the gyroscope heading and that of the magnetic element. The vertical pin supporting the compass needle can be pivoted at both ends, or an inductor element can be employed. The directive element must be nonpendulous.
The errors that occur in aircraft and small, fast vessels during alterations of course or speed can be avoided by mounting the compass on a platform kept horizontal by a gyroscope.