ITech IT-M3900D Series User Manual page 56

Power Supply Function
The heavy solid line illustrates the locus of possible operating points as a func-
tion of output. As shown by the horizontal portion of the line, the output voltage
remains regulated at its programmed setting as long as the load current remains
within the current limit setting. A CV status flag indicates that the output voltage
is being regulated and the output current is within its limit settings.
Note that when the output current reaches current limit, the unit no longer oper-
ates in constant voltage mode and the output voltage is no longer held constant.
Instead, the unit will now regulate the output current at its current limit setting.
CC Priority
In CC priority mode, the output is controlled by a constant current feedback
loop, which maintains the output current at its programmed setting. The output
current remains at its programmed setting, provided the load voltage remains
within the voltage limit setting. CC priority mode is best suited for use with bat-
teries, power supplies, large charged capacitors, and loads that are sensitive to
current overshoots.
In CC priority mode, the output current should be programmed to the desired
value. A positive voltage limit range should also be set. The voltage upper limit
should always be set to a value that is greater than the actual input voltage re-
quirement of the external load. The following figure shows the CC priority oper-
ating locus of the output.
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