KEPCO BOP 1KW-MG Operator Manual, Firmware Ver.4.12 and higher - Manual (Page 107)

BOP HIPWR 031014
3-41
input signal exceeds the limit value (either ±10V if the software limit is set to nominal, or a lesser
voltage for a user-determined software limit) clipping of the output voltage or current to the limit
will occur.
NOTE: If the system limits have been modified (PAR. 3.3.4), the output of the power supply will
never exceed the modified system limits. E.g, for a BOP 36-28MG, if the system volt-
age limit is modified to ±18V, applying a positive analog voltage to pin 11 that starts at
zero and rises to +10V causes the output to rise from zero and reach +18V when the
external reference reaches +5V. The output stays at +18V while the reference
increases from +5V to +10V since the system voltage limits for this example are ±18V.
3.4.3.2 VARIABLE GAIN USING EXTERNAL REFERENCE LEVEL
The BOP can function as a variable gain power amplifier similar to the fixed (inherent or nomi-
nal) gain amplifier as described in PAR. 3.4.3.1. The user can determine a new (lower) full scale
output value for the ±10V reference level (applied at pin 11, referenced to pin 10, of the Analog
I/O port) by configuring the Reference input as follows:
1. From the power-up screen press
$
and highlight Reference Input. Press
!
, highlight
ExtlRefLvl and press
$
. Then press
%
to apply the changes (without saving for power-up)
and exit.
2. To return to digital or local control, from the power-up screen, press
$
, then highlight Ref-
erence Input and press
!
. Highlight Internal and press
$
to save. Then press
%
to
apply the changes (without saving for power-up) and exit.
NOTE: Each time the Reference Input setting is changed, the unit generates an internal *RST
reset command (see PAR. A.11) which requires the BOP output and/or protection limits
to be reprogrammed.
For an external reference of ±10V, the nominal voltage gain (G
NOM-V
) of a BOP 36-28MG is
36/10 = 3.6. If the new full scale voltage for 10V is set to 29V, the voltage gain is changed from
3.6 to 29/10 = 2.9. The gain can be changed from the front panel, but the output is controlled by
the external reference signal and can not be changed from the front panel.
New Gain = New Full scale set at front panel / External reference that produces Full scale out-
put. This means that the External reference voltage, from +10V to –10V, can control the full
scale output voltage from +29V to –29V. The gain range is between zero and the nominal gain
of each model.
Once the feature is configured, the new full scale value is entered by changing the active setting
value of the main channel. This determines the full scale output to be produced by a 10V exter-
nal reference.
The gain in voltage mode is G
V
= V
SET
/10 where V
SET
is the desired full scale voltage (in Volts)
entered at the front panel.
The gain in current mode is G
A
= I
SET
/10 where I
SET
is the desired full scale current (in
Amperes) entered at the front panel.
NOTE: If the system limits have been modified (PAR. 3.3.4), the output of the power supply will
never exceed the modified system limits.