Latest products and information available at www.sealite.com
22
SL-75
3–5NM+ Solar Marine Lantern
The lanterns are available with optional GPS
fi
tted and provide the user with the ability to install
independently operating lanterns that all
fl
ash in synchronisation.
No additional power supplies, aerials or control systems are required, and with its microprocessor-
based system, the GPS option is speci
fi
cally designed to provide maximum reliability and performance
over a wide range of environmental conditions.
Operating Principle
Each light operates independently and requires no operator intervention. A minimum of 4 satellites
need to be in view for the built-in GPS receiver to collect time data. At dusk, the light sensor will turn
the light on. If time data is available the light will come on synchronised to every other light with the
same selected
fl
ash code.
Synchronisation is achieved using an internal algorithm based on the highly accurate time base and
time data received from the satellites. The satellite data is provided from a number of earth stations
using atomic clocks as the time base. Continuous self-checking ensures that the light will continue to
run in synchronisation.
Light Activation
At power-up the microprocessor checks that the internal GPS module is programmed correctly and is
able to provide valid time base and time data.
Once outside with a clear view of the sky, valid data should become available within 20 minutes.
Daylight Operation
During daylight hours the microprocessor is in idle mode to reduce power consumption. Time data
continues to be updated once per second. The microprocessor will automatically exit the idle mode as
soon as dark conditions are detected.
Dark Operation
When dark conditions are detected the light:
•
Checks for valid time data and is turned on after a delay based on the current time and the length
of the selected
fl
ash code;
•
If valid time data is not detected the light will turn on after approximately 10 seconds. This light will
not be synchronised.
•
If the light turns on unsynchronised it will continually check for valid time data. Once valid data is
found the light will automatically synchronise.
Note
: Lights will not synchronise if different
fl
ash codes are selected.
Optional GPS Synchronisation
