Campbell Scientific DCP100 GOES Data Collection Platform - Manual (Page 12)

DCP100 DATA COLLECTION PLATFORM
4
5. POWER SUPPLIES
5.1 12 AND 24 AHR SEALED RECHARGEABLE
BATTERIES
Typically, the system is powered with a 12 Volt,
12 AHr sealed rechargeable battery that
connects to a charging regulator and a solar
panel. The 12 AHr battery lasts 15 to 20 days
per charge. A 24 AHr sealed rechargeable
battery which lasts 30 to 40 days is available.
NOTE: This assumes the data are
transmitted for 30 seconds at 3 hour
intervals. The datalogger's scan rate is 1
second, and the sensors have negligible
power consumption.
A discharged 12 AHr battery is recharged by a
10 watt solar panel in 2 to 3 days when there
are a 1000 watts per square meter of
illumination and the solar panel temperature is
25
°
C. A 20 watt solar panel is available. The
minimum daily battery voltage should be
monitored with datalogger program Instruction
10, and output as a part of the user’s data
stream.
5.2 AC POWER AND DEEP-CYCLE
RECHARGEABLE BATTERIES
Although either the 12 or 24 AHr battery is
sufficient for most systems, applications with
high current drain sensors or peripherals (e.g.,
SDM devices) might require AC power or a
user-supplied deep-cycle rechargeable battery
that is trickle-charged with a 20 Watt solar
panel. Campbell Scientific's power supply
brochure and application note provide
information about determining your system's
power requirements.
5.3 DATALOGGER'S BATTERIES
The transmitter's power consumption is too high
for alkaline batteries. The 21XL's rechargeable
batteries do not source sufficient current for the
transmitter. Although the PS12LA 7 AHr battery
can power the transmitter, the battery only lasts
3 to 7 days per charge. One option is to have
the datalogger's batteries power the datalogger
and sensors, while the transmitter uses a 12
AHr battery, a 24 AHr battery, or a deep-cycle
battery.
NOTE: The datalogger's batteries should
be removed when not in use.
Rechargeable batteries should be trickle
charged with either Solar or AC power
through a charging regulator.
6. INSTALLATION
6.1 WIRING
The DCP100 hardware (excluding the battery
and solar panel) and the datalogger are
premounted and prewired. The enclosure's
ground lug must be connected to an
appropriate earth ground (see Table 6.1-1).
6.2 BATTERY
Before installing the battery, turn OFF the
charging regulator’s (CH12R) power switch. To
install the battery, remove the battery bracket
from the DCP100 and insert the battery facing
outward into the bracket. When inserting the 24
AHr battery into its bracket, the battery’s power
connections (posts) go on the top side where a
section of the bracket has been cut away.
Reattach the bracket to the DCP100’s
enclosure, and connect the battery cable (see
Table 6.1-1). The antenna must be connected
to the transmitter before turning on the
CH12R's power switch.
6.3 ANTENNA
You mount the antenna to a tripod, tower, or
vertical 1.5" OD pipe (see Figures 6.3-1 through
6.3-3). The antenna is then oriented towards
the satellite by using a computer program (see
Appendix C). This program prompts you for the
satellite's longitude (provided by NESDIS) and
the antenna's longitude, latitude, and height. It
then calculates the antenna's elevation and
azimuth (see Figure 6.3-4). You must also
account for local magnetic declination (see
Appendix G).
After the antenna is properly oriented, insert the
antenna cable into the enclosure's largest
compression fitting and connect the cable to the
transmitter.
CAUTION: The antenna must be connected
before transmission or the transmitter will be
damaged.