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© 2006, Elektro-Automatik GmbH & Co. KG
Irrtümer und Änderungen vorbehalten
EN
Instruction Manual
EL 3000 A Series
Date: 05-30-2017
6.7.2 Level B
When switching to „Level B“ with the selector
Level
Control(3)
, the set values of Level B become active. This
mode works the same way as
Level A
.
In
Level B
mode, the load can be switched to remote
control from a PC and via the interface, in order to control
and monitor it like during manual operation.
When changing to remote control the currently selected
Level Control
setting is retained and can then be
changed by a command, except with GPIB interface
IF-G1.
6.7.3 Level A/B (pulsed operation)
This mode combines two set values A and B with two
seperately adjustable pulse widths for A and B. The
electronic load generates automatic set value leaps be-
tween A and B with those values. The rise/fall time is also
adjustable. This pulsed operation is only applied to the
set value which belongs to the selected MODE, means
in CV the voltage is affected etc. The other set values
remain constant. Also see figures 11 and 12.
The pulse width of A is dedicated to the set value of A etc.
The sum of the pulse widths results in a period
t
, which
represent a certain frequency
f=1/t
. The pulse widths are
adjustable from 50µs...100s which results in a period
of 100µs...200s, which corresponds to a frequency of
10kHz...0.005Hz.
Note:
Alarms like OVP or PF (power fail) (see section 6.1,
item „Alarm management“) which switch off the input also
stop the pulsed operation. It can be resumed as soon as
all alarms are gone and have been acknowledged.
External trigger
The external switchover between A and B, realised with
the trigger input (analogue interface), is only available
in Level A/B mode. The trigger input has to be activated
in the setup menu with the option
Trigger mode
(see
. The default setting is
internal
.
By setting it to
external
the switchover between A and B
can only be done via the trigger input.
Handling the device
The adjusted rise/fall time is still effective here, but the
pulse widths are now determined by the trigger signal,
which is fed into the trigger input. The trigger signal
must be square wave, for levels see „8. The analogue
interface“.
As long as external trigger is active the pulse times of A
and B are not indicated in the display and are also not
adjustable anymore. The display also indicates the status
with „
Ext. trigger
“.
The rotary knob
Selection(5)
is used to select the set
values for A and B, as well as both pulse times, and
Set-
ting(6)
is used to change them. The display shows the
letters
A
and
B
to indicate the assignment. When navi-
gating between the set values, an arrow (->) is placed in
front of the currently selected one. A rise/fall time for the
pulsed operation is also adjustable. Both, rise and fall
time, are identical and can‘t be set seperately for A and
B. It is displayed as slope in the format ∆value/∆time, like
for example in figure 10 with 100A/20ms.
The
Level A/B
operation is started as soon as the load
input is set to on.
Note:
during Level A/B operation following applies: the
set value of A must always be greater than or equal to
B. Thus you can adjust A downwards only to the value
of B and B upwards only to the level of A. If it seems that
Level A is not adjustable somehow this might be caused
by Level B being the same value.
Figure 11
Figure 10. Level A/B operation with pulse width adjustment
Figure 9. Normal load operation in CP regulation mode
