Omega Engineering OMB-DBK-34A, User Manual

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An Introduction to Power-Related DBKs
The power-related DBK options are the DBK30A, DBK32A, DBK33, DBK34, and DBK34A. From the
standpoint of providing reliable power, these DBKs have proven convenient in laboratory, automotive, and
field applications.
Input power for these devices can come from any 10 to 20 VDC source, or from an AC source via an
appropriate AC-to-DC adapter.
A brief synopsis of the DBK power options follows. Refer to the respective document modules for complete
information.
DBK30A
module - provides power at 14 and 28 VDC with a rated capacity of 3.4 A-hr @ 14 VDC.
The DBK30A’s 28 V output will power 4 to 20 mA transducers.
The module’s rechargeable power supply can
power DBK modules in situations where AC mains are not available.
Note : Some transducers (e.g., 2-wire 4-20 mA transmitters, bridge-configured sensors, etc) require an
excitation voltage in order to work properly. The DBK30A supplies 14 and 28 VDC. Consult
transducer documentation before applying power.
DBK32A
- provides ±15 VDC @ 500 mA.
DBK33
- provides ±15 VDC @ 250 mA and +5 VDC @ 1000 mA.
The DBK32A and DBK33 power cards attach directly to the P1 analog expansion bus where they supply
power to DBK analog expansion cards. The DBK32A and the DBK33 can be powered from an included AC
adapter, an optional DBK30A battery module, or from a +10 to +20 VDC source such as a car battery.
When installed in a DBK10 three-slot expansion chassis, the DBK32A or DBK33 supplies power
to the analog DBK [that is to receive power] via a CA-37-x cable.
If used with the DBK41 ten-slot expansion enclosure, the DBK32A or DBK33 installs into one of the analog
expansion slots on the DBK41’s backplane. A power card in any DBK41slot (other than the leftmost, when
viewed from the rear) will power the other cards that are connected to the DBK41’s backplane.
CAUTION
If using a DBK32A or a DBK33 with a DaqBook/100 Series, DaqBook/200 Series, or a
DaqBoard [ISA type] device, you must entirely remove the shunt jumpers from JP1.
Failure to do so will result in damage to the 8254 timer chip. Refer to the power card
document modules and to the Daq device Hardware sections of the DaqBook/100 Series
and DaqBook/200 Series, and DaqBoard [ISA] user’s manuals for JP1 locations and
configurations.
DBK34A
module – provides 12 or 24 VDC with a 5.0 or 2.5 A-hr capacity (respectively).
The DBK34A is classified as a UPS / Battery module. The module can be used for in-vehicle testing
in scenarios where the vehicle’s electrical system does not affect acquisition device power during
starter-current surge, or power-off.
Daq Systems
967794
DBK Basics, pg. 15