Specifications

6-1
Section 6. CR1000 Power Supply
Reliable power is the foundation of a reliable data acquisition system. When
designing a power supply, consideration should be made regarding worst-case
power requirements and environmental extremes.
Excessive switching noise or AC ripple present on a DC power supply can
increase measurement noise. Noise sources include power transformers,
regulators, and grid or mains power inclusively. Using high quality power
regulators reduces noise due to power regulation. Utilizing 50 or 60 Hz
integration times for voltage measurements (see Section 4) improves rejection
of power supply induced noise. The CRBasic standard deviation instruction,
SDEV() can be used to evaluate measurement noise.
Contact Campbell Scientific if assistance in selecting a power supply is needed,
particularly with applications in extreme environments.
6.1 Power Requirement
The CR1000 operates from a DC power supply with voltage ranging from 9.6
to 16 V. It is internally protected against accidental polarity reversal. A
transient voltage suppressor (TVS) diode on the 12 V power input terminal
provides transient protection by clamping voltages in the range of 19 to 21 V.
Sustained input voltages in excess of 19 V can damage the TVS diode.
The 12V and SW12 terminals on the wiring panel are not
regulated by the CR1000; they obtain power directly from
the POWER IN terminal. When using the CR1000 wiring
panel to source power to other 12 V devices, be sure the
power supply regulates the voltage within the range
acceptable to the connected device.
6.2 Calculating Power Consumption
Read more! Section 3.3 Specifications -- System Power Requirements
System operating time for batteries can be determined by dividing the battery
capacity (ampere-hours) by the average system current drain (amperes). The
CR1000 typically draws 0.5 mA in the sleep state (with display off), 0.6 mA
with a 1 Hz sample rate, and >10 mA with a 100 Hz sample rate.
6.3 Campbell Scientific Power Supplies
Campbell Scientific carries several power supplies including alkaline and solar
options. Complete power supply information is available in manual or
brochure form at www.campbellsci.com.
6.4 Battery Connection
When connecting external power to the CR1000, remove the green POWER IN
connector from the CR1000 front panel. Insert the positive 12 V lead into the
terminal marked “12V”. Insert the ground lead in the terminal marked “G”
CAUTION