29
Communication:
•
Serial (RS-232):
Available in units manufactured, or upgraded, after January 1st, 2005
•
SCSA:
AVCOM’s Graphical User Interface used for serial communications.
Accessories:
•
Battery Pack:
BP3010 additional battery pack to extend battery life (1 pack supplied, 2 max)
•
Carrying Case:
AVPAC custom CORDURA padded travel case with strap
BATTERY INFORMATION
The PSA-37XP ships with a single very-high capacity Lithium Ion battery. A single battery pack has
over 2AH of charge capacity at 10.5V to 12.6V. One additional battery can be added to increase the
capacity to 4AH total. The PSA-37XP draws about 1.3A continuous on average, so you can figure an
approximate time for operation at #AH/1.3. So for a single battery pack, you will get 2AH/1.3A =
1.5Hours. In reality there are other losses so the practical time is about 1.25 Hours.
Lithium Ion batteries while very light for their capacity have their drawbacks. For example they begin to
self-discharge at high heats which only compounds the heating issue, so the PSA -37XP will automati-
cally shut down when the temperature reaches 45C inside of the case. The heatsink of the dummy load
is close to the power supply, so if you are performing a lot of high power testing, you may find the
power on the PSA-37XP will shut off once the unit gets too hot. This is to prevent significant problems
with the batteries and the temperature circuit should not be compromised.
Lithium Ion batteries will also not deliver full current capacity at low temperatures, so depending on fea-
tures used in the PSA-37XP, it may or may not power up below –2C. If you warm the PSA-37XP inside
of a vehicle for instance, once powered up the battery will warm itself during the discharge cycle.
Adding Batteries
If you are adding another battery pack to an existing unit, discharge the existing battery fully by leaving
the PSA-37XP on until it powers itself off. Then it is safe to add the new battery pack. Otherwise the
new battery arrival will be charged too fast by the battery already in the unit and possible damage to
the battery could occur. The batteries do have a protection circuit built in to prevent damage of this na-
ture, but it is better to be safe than sorry.
Unfortunately due to the very specific application these batteries are designed for, any run -of-the-mill
lithium battery will not work in the PSA-37XP. The batteries used in this design have an unusual volt-
age per cell specification due to the extended temperature range they can operate in, as the chemical
composition was designed for military use at one time. Other lithium batteries used in the PSA -37XP
could be overcharged casing damage to the batteries and to the PSA -37XP. Please use ONLY the
specified batteries.
Using an external DC power source
Some people may wish to power the PSA-37XP using vehicle power (13.8V) or a larger capacity exter-
nal power supply. This can be done through the battery input jacks, the connector is a 3.5mm center
positive jack. Voltage range must be between 11V and 15.5V, and capable of 1.5A at 11V, and 1.1A at
15.5V. For more information call AVCOM of Virginia, Inc. 804-794-2500
