Campbell Scientific CR3000 Micrologger - Manual (Page 88)

Section 7. Installation
88
Figure 31: Sealed rechargeable battery wiring
7.4.3.2.3 Low Profile (No Battery) Base
A CR3000 with the low-profile base (see the appendix Battery Bases
(p. 567)
) will
not have an internal power supply. In this configuration, power is supplied to the
CR3000 by attaching an external 12-Vdc power source to the POWER IN
connector on the lower left of the CR3000 face. The appendix Power Supplies
(p.
566)
lists power supplies available from Campbell Scientific for use with a low
profile base. See the section External Batteries
(p. 83),
for instructions on
connecting external power supplies to the CR3000.
7.4.4 Vehicle Power Connections
If a CR3000 is powered by a motor-vehicle power supply, a second power supply
may be needed. When starting the motor of the vehicle, battery voltage often
drops below 9.6 Vdc. This causes the CR3000 to stop measurements until the
voltage again equals or exceeds 9.6 Vdc. A second supply can be provided to
prevent measurement lapses during vehicle starting. The figure Connecting
CR3000 to Vehicle Power Supply
(p. 89)
illustrates how a second power supply
should be connected to the CR3000. The diode OR connection causes the supply
with the largest voltage to power the CR3000 and prevents the second backup
supply from attempting to power the vehicle.