Boat travel distance measurement device - has propeller driven flywheel containing magnet operating blade switches connected to EM pulse counter driving display

摘要

The distance reading is provided in the cabin by electrical transmission from a detector which senses propeller rotations. A propeller drives the shaft of a log to drive a counter via a line assembly. A flywheel on the shaft contains a magnet which operates a flexible blade switch in a support. The switch contacts are connected by a cable to a display unit (11) containing an electromagnetic counter (12). The figures are advanced when the electrical divider circuit (13) provides pulses. The circuit provides correlation between number of turns of the propeller and distance travelled. The figures are illuminated by a lamp (16) powered from a zener diode voltage regulator (15). When it is necessary to obtain more than one signal for each revolution of the propeller, a number of magnets or switches can be added to the existing shaft.