Abstract: A marine propulsion device including a drive unit which is adapted to be mounted on a boat and which includes a propeller shaft, an internal combustion engine being drivingly connected to the propeller shaft and including an alternator generating first and second alternating current voltages, and a circuit for receiving the first and second alternating current voltages and for generating, in response to the first and second alternating current voltages, first and second direct current voltages for providing electrical power to the internal combustion engine.

Abstract: An indicator of operating conditions in an internal combustion marine engine displays information about a plurality of engine conditions in response to signals communicated from a remote location over a single wire. Different engines troubles are identified by rectangular voltage wave forms of different duty cycles on the single wire. A logic circuit detects a particular duty cycle and actuates an alarm in response to the detected signal. It is thus possible to alert an operator at a remote location to conditions such as low oil pressure, zero oil pressure or overtemperature by use of a single wire connected to the engine.