X-Load - Elgar SmartWave SW5250A Operation Manual

General Description SW 5250A•SW 3500A•SW 1750A
The SmartWave allows you to select boost On or Off. In some applications, the
transient response time associated with the boost function is unacceptable, but tight
RMS regulation is still required. Boost should be turned off in such cases. An example
is when a sequence is programmed with various sags and surges which must have
sharp transitions from one RMS voltage to another.
The SmartWave defaults to Boost Off in Sequence mode if the sequence "End Mode" is
selected to be "Program Menu," the system boost control should be set off to prevent a
"tail" from occurring during the transition out of the sequence mode (due to the servo
tracking to a new steady state condition). See the System menu, Section 3.3.7.
1.12.3

X-Load

The bane of all closed loop amplifiers is loop stability: gain and phase margin. The
SmartWave is guaranteed to be stable for power factors from 0 leading to 0 lagging.
The most difficult load for most amplifiers, as with the SmartWave, is driving large
capacitive loads (10-10,000µF).
Though stable with its normal loop compensation, the SmartWave can provide
additional phase/gain margin with these unusual loads by selecting X-Load On. This
significantly improves the transient response of the amplifier.
X-Load should only be used for reactive loads, and with programmed frequencies of
less than 1000 Hz.
1-14 Operation Manual