Figure 3.1 Operating Modes - Xantrex XFR 7.5-140 Operating Manual

Local Operation
Standard Operation
Output
Voltage
V SET
O

Figure 3.1 Operating Modes

Constant Voltage Mode Operation The power supply will operate in constant
voltage mode whenever the load current I
or: I < I
L
In constant voltage mode, the power supply maintains the output voltage at the
selected value (V
Constant Current Mode Operation The power supply will operate in constant
current mode whenever the load resistance is low enough that the load current I
equal to the current limit setting I
In constant current mode, the power supply maintains the output current at the
selected value (I
Automatic Mode Crossover This feature allows the power supply to
automatically switch operating modes in response to changing load requirements. If,
for example, the power supply was operating in Constant Voltage Mode (I
and the load changed so that the load current (I
setting (I
Mode and the output voltage would vary in response to changes in load current. If
the additional load was subsequently removed so that the load current was again less
than the current limit setting, the supply would automatically return to Constant
Voltage Mode.
58
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Constant Voltage
Mode Region
Crossover Point
Constant Current
Mode Region
O
I SET
(Note: I = V / R ).
SET L SET L
) while the load current I
SET
) while the load voltage varies with the load requirements.
SET
), the power supply would automatically switch into Constant Current
SET
>
R V
L SET
I
SET
=
R V
L SET
I
SET
<
R V
L SET
I
Where:
SET
R
L
V
Output
SET
Current
I
SET
is less than the current limit setting I
L
varies with the load requirements.
L
(Note: V =I R ).
SET L SET L
) became equal to the current limit
L
Operating Manual for XFR 1.2kW Series Power Supply
= Load Resistance
= Output Voltage Setting
= Output Current Setting
,
SET
is
L
< I ),
L SET