Gary built a Navigation Light Controller that has the following
- Provide an interface to the user for control, display, and alarms.
- Provide an automatic mode that chooses masthead tricolor if the engine
is off, or deck level navigation lights and steaming light when the engine
- Provide manual selection of anchor light, deck level navigation lights
and steaming light, deck level navigation lights only, or masthead tricolor.
- Turn on instrument lights whenever any navigation lights are on.
- Provide manual control of the masthead emergency strobe and the foredeck
- Continuously monitor the current being drawn by those lights that
are on. Sound an alarm if that current falls below a minimum value.
i.e. indicate burnt-out bulbs or failed connections.
- Pass a small current through the circuits of those lights that are
off. Sound an alarm if that current does not flow, indicating a fault
in the circuit.
- Display the status of the exterior lights on an interior mimic panel.
- In automatic or anchor mode, turn off navigation or anchor lights
when dawn arrives.
- Provide engine and daylight status to an attached computer.
- Accept commands from an attached computer.
These functions are accomplished by the use of a small microprocessor (a
PIC 12C509, labeled 9/19 in the picture below). Input and output to the
processor is via a set of shift register chips.
There is a set of manual switches inside the DC panel that parallel
the controller and can be connected in place of the controller as a backup.
There is also a substitute controller board that excludes the microprocessor
and implements only basic control of the navigation lights.