© EPS Stromversorgung in 2022, this information is subject to change without notice
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30000800_manual_psb_10000_4u_30kw_en_04
The same occurs with a positive load step, i.e. low load to high load. There the output collapses for a moment. The amplitude
of the overshoot resp. collapse depends on the device model, the currently adjusted output voltage and the capacity on the
DC output and can thus not be stated with a specific value.
Depictions:
Example for a neg. load step: the DC output will rise above
the adjusted value for a short time. t = transient time to settle
the output voltage.
Example for a pos. load step: the DC output will collapse
below the adjusted value for a short time. t = transient time
to settle the output voltage.
3.3.1.2
Minimum input voltage for maximum current (sink mode)
Due to technical reasons, all models in this series have a minimum
internal resistance that requires to provide a specific minimum input
voltage (U
MIN
) in order for the device to be able to sink its rated current
(I
MAX
).
This minimum input voltage varies from model to model and can eas-
ily be determined. If less voltage than U
MIN
is supplied, the load propor-
tionally draws less current, which can be calculated easily.
See principle view to the right.
I(A)
U(V)
I
Umin
Imax
3.3.2
Current regulation / constant current / current limiting
Current regulation is also known as current limiting or constant current mode (
CC
).
The current in the DC terminal of the device is held constant once the output current (source mode) to the load resp. the cur-
rent consumed from the load (sink mode) reaches the adjusted limit. Then the device automatically switches to CC. In source
mode, the current flowing from the power supply is only determined by the output voltage and the load’s true resistance. As
long as the output current is lower than the adjusted current limit, the device will be either in constant voltage or constant
power mode. If, however, the power consumption reaches the set maximum power value, the device will switch automatically
to power limiting and set voltage and current according to P = U * I.
While the DC power stage is switched on and constant current mode is active, the condition “CC mode active” will be indicat-
ed on the graphics display by the abbreviation
CC
and this message will be passed as a signal to the analog interface, as well
stored as status which can also be read as via digital interface.
3.3.2.1
Voltage overshootings
In certain situations it’s possible that the device generates a voltage overshooting. Such situations are when the device is
in CC, with the actual voltage being unregulated, and either a jump in the current set value is initiated which could bring the
device out of CC or when the load is suddenly cut from the power supply by an external means. Peak and duration of the
overshooting aren’t exactly defined, but as rule of thumb it shouldn’t exceed a peak of 1-2% of the rated voltage (on top of
the voltage setting), while the duration mainly depends on the charging state of the capacities on the DC output and also the
capacity value.
