ADF SERIES™ OPERATION MANUAL
SECTION 6:
Front Panel Operation
Entire Contents Copyright 2018 by Pacific Power Source, Inc. (PPS) • All Rights Reserved • No reproduction without written authorization from PPS.
ADF Series Power Source Operation Manual Page 96 of 349
6.4.10 AUTO RMS Function – Steady State
The AUTO RMS mode, if enabled, causes the AC voltage output value to be calculated as a
true RMS voltage of the waveform selected. This means the output RMS voltage will remain
at the programmed level regardless of a change in waveform shape. This may or may not be
what the user intends. For example, adding a transient spike on a sine wave as part of a user
defined waveform will cause the overall RMS value to increase so the sinewave portion of
this user defined waveform will be attenuated somewhat when used.
When AUTO RMS is disabled, RMS calculation of substituted waveforms does not occur so
the output RMS voltage may change from the set value if the waveform selected for output
is not a sine wave. This mode is preferred if switching to a user waveform that has a
different mathematical RMS value from a sine wave should NOT result in the output voltage
amplitude being adjusted to maintain the same RMS level as with a sine wave. As in the
previous example, adding a spike or a dip in part of the sinewave will not affect the output
amplitude of the sinewave portion.
Note: The setting of the AUTO RMS mode is important when CSC mode is used as CSC
mode uses the measured output RMS voltage to adjust the output to maintain
voltage regulation.
This mode can be set by sending the
[SOURce:]WAVEFORM:AUTORMS command over one of the
Digital control interfaces.
The following examples illustrate the different behaviors between AUTO RMS mode ON and OFF.
6.4.10.1 AUTO RMS ON Mode:
In the example below a, 100Vrms sine wave is swapped for a half wave rectified ac
waveform. The RMS value of this non-sinusoidal waveform is 1.414x that of a sine wave so
the peak value is increased to maintain a 100Vrms output voltage with this wave shape. Not
that there is a considerable amount of DC offset present as well due to this non-symmetrical
waveform.
To Next Page
