current in order to regulate the voltage. The regulating voltage is adjustable from full scale of
the range selected to approximately zero. The constant voltage mode is used to simulate a
battery to a battery charger or for special applications, such as a shunt regulator.
CAUTION
:
Never use the constant voltage mode for testing a constant voltage source. The
regulators of the two devices will buck each other trying to gain control of the voltage,
which in turn will lead to an unstable condition causing damage to the load
CP — Constant Power Mode (Basic Mode)
In constant power mode, the Dynaload will dissipate a set wattage anywhere up to the
maximum power rating of the unit. The Dynaload will automatically adjust the current level
inversely in response to a change in voltage. The constant power mode is NOT affected by
changes of the voltage or current range.
However the XBL has a 2V minimum for CP
operation. If the input signal is less than 2.0 V the CP mode will not activate.
CAUTION: - RBL/ XBL difference-
An RBL In CP mode, If the source voltage decays to zero volts the load will
attempt to draw infinite current until current limit is reached.
Full Scale Range Switching
The XBL Series provides selection of one of three full scale input voltage ranges and one of
three full scale input current ranges. The full scale voltage and current ranges may be selected in
any combination resulting in nine operational ranges per unit. These are selectable over the bus
as ranges (1 thru 9 refers to IEEE-488 syntax section).
The selectable ranges provide increased resolution. For example: Setting 10 amps may be
difficult using the 1000 amp full scale. By selecting a lower full scale, 100 amps, the resolution
of the meters, IEEE-488 control, programming input and the current sample output are greatly
increased.
Master/Slave Parallel Operation
The synchronized paralleling function allows the user to connect two loads in parallel. One unit
is controlled through normal operation, the master. The additional unit, the slave, is connected
via a RJ 11/ RJ 12 telephone type cable and responds to the control signals sent by the master.
In all operating modes, the slave units are controlled by the master.
Operating two XBL Dynaload units in parallel requires a number of control signals to be shared
among the units. These signals are present on two RJ 11/ RJ 12 connectors on the rear of the
XBL See “Master Slave Connections”.
NOTE:
Slave mode selects the remote constant current mode of operation. The master unit
provides the appropriate control input with respect to mode and amplitude.
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