AMETEK XT Series - Manual (Page 34)

Operation
Operating Modes
34 Operating Manual for XT Series Power Supply
Constant
Voltage Mode
Operation
The power supply will operate in constant voltage (CV) mode whenever the load
current I
L
is less than the current limit setting I
SET
or: I
L
< I
SET
(Note: I
L
= V
SET
/ R
L
).
In CV, the power supply maintains the output voltage at the selected value (V
SET
)
while the load current I
L
varies with the load requirements.
To use the power supply in CV mode, either set the current limit to maximum by
turning the current control to its extreme clockwise position, or take the precaution
of setting a desired maximum current, then set the voltage control to the desired
voltage.
Constant
Current Mode
Operation
The power supply will operate in constant current (CI) mode whenever the load
resistance is low enough that at V
SET
the load current would be greater than the
current limit setting I
SET
.
In CI mode, the power supply maintains the output current at the selected value (I
SET
)
while the output voltage varies with the load requirements.
To set the Current Limit, connect a shorting lead across the output terminals, turn the
voltage control a half-turn clockwise, and set the desired maximum value of current
limit by turning the current control slowly clockwise to the desired level. Then,
disconnect the shorting lead from the output terminals. The power supply will now
automatically switch into current limiting mode (current regulation) as soon as the
preset current level is reached. To operate the supply in CI mode, set the current limit
as described above, then set the voltage control fully clockwise or to the compliance
voltage of the circuit. As soon as the supply starts operating in current mode, the red
current mode LED will turn on.
Note The control circuits have been designed to allow you to set output voltage and
current up to 5% over the model-rated maximum values. The power supply will operate
within these extended ranges, but we cannot guarantee full performance to
specification.
V
SET
R
L
------------- I
SET
>