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35
Instruction Manual
EL 9000 A Series
EN
Date: 11-16-2011
A changeover to regulation mode
CR can reset the set
values of resistance, current and power to their nominal
values, if the parameter
Keep set values
has been set
to
no
in the setup. If set to
yes
, the least adjusted set
values are kept. Also see „7.1. The setup menu“.
6.7 Usage of Level A and Level B
Introduction
The terms Level A and Level B stand for two different
The terms Level A and Level B stand for two different
sets of set values which can be switched over in order
to generate a value step. This is either done manually
with the selector
Level Control (3) or externally via the
analogue interface with the trigger input (only in
A/B
mode) or automatically (in
A/B mode).
Each of them,
A and B, has five set values dedicated to
the four regulation modes. That means, that the set value
of current is dedicated to constant current mode etc. In
CP mode you can, for example, adjust two set values for
power, switch between them and generate power steps.
When using the A/B mode (see 6.7.3), this switchover
happens automatically, in combination with the adjustable
pulse widths (i.e. pulse times) of A and B. This generates
a square wave shaped set value, whose high level is
represented by the A value and whose low level by the
B value and whose period time (and thus frequency) by
the sum of the variable pulse widths of A and B. These
also determine the so-called duty cycle. An example:
A = 10ms, B = 90ms, this results in a period time of 100ms
(= 10Hz) with 10% duty cycle.
6.7.1 Level A
When switching to „Level A“ with the selector
Level
Control(3), the set values of Level A become active.
This is only possible, if the status is not
Remote mode
or
External mode
. After switching to
Level A mode the
display shows
Level A.
An arrow (->) is placed next to
the set value which is dedicated to the currently chosen
regulation mode, in order to be instantly adjustable.
The set value(s) can be selected with
Selection(5) and
changed with
Setting(6). Which set values are selectable
depends on the regulation mode. In constant current
mode these are, for example, the current and the power,
because the set value for resistance is only available in
resistance mode and the voltage value must be set to zero
in constant current mode. See figure 9 on the next page.
The set values of this mode are kept unchanged until
The set values of this mode are kept unchanged until
they are adjusted again, even if the load is switched to
Level B, A/B or Battery test. This does not apply if the
parameter
Keep set values
has been set to
no
(see
„7.1. The setup menu“). Then the set values are reset to
default values, depending on the preselected mode (also
Level A 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 selec-
When changing to remote control the currently selec-
ted
Level Control setting is retained and can then be
changed by a command, except with GPIB interface
IF-G1.
Handling the device
A changeover to regulation mode
CV can reset the set
values of voltage, power and current to their nominal
values, if the parameter
Keep set values
has been set
to
no
in the setup. If set to
yes
, the least adjusted set
values are kept. Also see „7.1. The setup menu“.
Note: the CV regulation can not be used in combination
Note: the CV regulation can not be used in combination
with the battery test mode. Selecting it for battery test will
indicate an error message on the display.
Note: the voltage set value, which is assigned to the
Note: the voltage set value, which is assigned to the
regulation mode CV, must be set to 0 in any other regu-
lation mode. That‘s why it is not accessible in the manual
operation in the CC, CP or CR modes.
During
During
remote control the voltage set value can be sent
to the device, but will be ignored and an access error will
be reported by the communication.
During
During
external control (analogue interface) there is an
exception: the voltage set value must be given and can
be used as desired, but should be set to 0V if normal CC,
CP or CR operation is required.
CP
means constant power. Here are the set values of
power and current adjustable. In this mode the device
withdraws as much current as neccessary from the
feeding source in order to consume the adjusted power,
dependant on the input voltage (P = U * I). In case the
input voltage is so low that the withdrawn current exceeds
the nominal current of the device, the adjusted power can
not be achieved. Simultaneously, the current limitation
becomes active.
A changeover to regulation mode
A changeover to regulation mode
CP can reset the set
value of current to its nominal value and the set value of
power to 0, if the parameter
Keep set values
has been
set to
no
in the setup. If set to
yes
, the least adjusted set
values are kept. Also see „7.1. The setup menu“.
CR
means constant resistance. The device features
two resistance ranges. For values refer to the technical
specifications section.
The CR regulation mode is only active as long the switch
The CR regulation mode is only active as long the switch
Mode(2) is set to one of the two resistance ranges. Both
ranges act the same way, they only differ in the higher
resolution and accuracy of the lower resistance range.
In this mode, the set values of resistance, current and
power are adjustable.
This regulation mode loads the feeding voltage or current
This regulation mode loads the feeding voltage or current
source so much that the adjusted resistance results from
the relation of input voltage to input current (R= U / I). In
case the input voltage is so high that the input current ex-
ceeds the nominal current value, the adjusted resistance
can not be achieved.
Simultaneously, the current limitation becomes active. If
Simultaneously, the current limitation becomes active. If
the product of input voltage and input current, i.e. the po-
wer, exceeds the nominal power of the device, the power
limitation becomes active. Then the adjusted resistance
can also not be achieved.