Nautical log with a pressure comparator - has a transmission unit which controls a servo system through a differential transformer

摘要

The nautical log includes a servomotor, a cam drum and elements for display and further transmission of new speed values to further evaluation points. It comprises an additional unit controlling the main unit in a low speed range. It has a second, sensitive pressure comparator, a second transmission unit, differential transformer, servomotor and a cam drum, a synchro in the main unit and a synchro comparator in the additional unit, an angle detector with a relay for switching over from the main to the auxiliary unit and vice versa on crossing the limit between the low and high speed ranges. There are valves between the pressure comparator in the additional unit and a pressure head.