Sentek RT6, Hardware Manual

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SENTEK
Page 24
Power sources
Ni-Cad charger
Power modes
The following power sources can be applied to the
Main Board :

Solar panel which is rated at 10 watts at 12 volts

External DC supply which can range from 16 to
24 volts DC capable of supplying 1.5 amps. This
can be from available DC supply or via two 12
volt car batteries (in series to give 24 volts)

External AC supply which can range from 12 to
16 volts AC. This can be from available low
voltage AC supply or via a 240 volt AC plug
pack which delivers 16 volts AC at 1.5 amps.
The data logger board is fitted with a Ni-Cad battery
which is also charged by the solar panel (or external
power supply) or the SLA battery. This battery
protects the contents of the data memory and
time/date clock if the logger is removed to download
data in the office. Once removed from the logging
facility the data is secure for approximately 2 days.
Connecting the logger to an "Office Download
Cable" which is connected to power will charge this
battery, thus prolonging the time the logger can be
removed from the logging facility.
There are 3 power modes:
1.
No logger connected. With the battery cable
plugged into the main board and without the
logger plugged in, the battery charging circuit is
active and is ready to receive charge from the
external supply. This is done so that the battery
can continue being charged while the logger has
been removed from the logging facility for
downloading.
2. Logger present. When the logger is connected to
the unit then power is applied only to the
circuitry that runs continuously. This is done to
minimize power drain.
3. Sampling Sensors. During sampling of data from
the sensors, only the circuitry that is required is
powered. This is under control of the logger and
is done also to minimize power requirements of
the system.