Argantix KDC 100-100, User Manual

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User Manual
KDC Series II DC Power Supplies 51
4.4 Programming output transient lists
The output transient system allows sequences of programmed voltage and or current changes to
be executed in a time controlled manner. Changes can be either step changes (maximum slew
rate) or ramps (specified slew rates). Keep in mind however that the output will follow the
programmed changes as fast as the DC module can follow the controller signal. This is often a
function of the load. For example, stepping to a higher output voltage with no load connected will
invariably result in a faster slew rate on the output than under full load conditions. This is due to
the need to charge up the output storage capacitors. Under no load conditions, more current is
available to so than under full load conditions. Conversely, down programming will be
considerable faster under full load conditions than it is under no load conditions as the load will
enable the output storage capacitors to discharge faster. Note that a special bleeder circuit is
provided in the KDC Series to help pull down the output voltage under no or light load conditions
to accomplish faster slew down rates.
The section provides some examples of programming output changes (transients). Transients are
defined as a series of numbered steps in a list. The list is executed sequentially. Each step has a
number of fields that can be set by the user:
Voltage, Voltage slew rate, Current, current slew rate, Dwell time, Trigger out.
The voltage and current settings are the same as one would do form the setup screen using the
knobs. At each step, the output will be set to the specified voltage and/or current. The rate of
change is determined by the slew rate set. If the voltage is changed from 10 Vdc to 20 Vdc and
the V slew is set to 100 V/sec, the voltage will ramp from 10 to 20 Vdc in 100 msec. ( [20 - 10] /
100 = 0.1 sec). The dwell time is the time the output will remain at this setting. In this example, it
should be set long enough to reach the final programmed value of 20 Vdc, e.g. it should be at
least 0.1 sec. If not, the voltage will never reach the final value of 20 Vdc before the next step in
the transient list is executed. The dwell time may be set longer than 0.1 sec in this example. If for
example the dwell time is set to 1.0 sec, the voltage will ramp from 10 Vdc to 20 Vdc over a 0.1
sec period and then remain at 20 Vdc for 0.9 sec.
Once the dwell time set for a step in the list expires, the next step is entered (if available, if not,
execution stops and the output remains at the final values set in the last step of the list.)
Note that while there are parameters for both voltage and current level and slew rates, there is
only one dwell time, which applies to each step in the transient list.
The following sample illustrates the use of transient system to program controlled output changes.