Single-wire engine indicator device

摘要

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.