User manual

GMC-I Messtechnik GmbH 21
5.8 Parallel Operation
The outputs of any number of KONSTANTERs can be parallel con-
nected if output current from a single KONSTANTER is insufficient for
your application.
CAUTION
If outputs with different nominal voltage values are parallel
connected, all of the outputs must be limited to the lowest
nominal voltage value within the system.
This setting is accomplished with the Ulim parameter.
5.8.1 Direct Parallel Operation
Function
• Simplest way to increase current to the consumer to a level greater
than that provided by a single KONSTANTER.
• KONSTANTERs with different nominal output voltages can be used.
However, all voltage setpoints must be limited to the same value.
• Less suitable for constant voltage operation
Wiring
Figure 5.8.1 a Wiring for Direct Parallel Operation
Procedure
• Deactivate all outputs.
• Adjust voltage setpoint values USET for all parallel connected KON-
STANTERs to approximately the same value:
Uset = USET1 = USET2 = USET3 = USETn
• Adjust current setpoint values ISET such that the desired
cumulative current setpoint value Iset is achieved:
Iset = ISET1 + ISET2 + ISET3 + ... + ISETn
• Activate the outputs.
Functional Principle
• Immediately after power-up, the KONSTANTER with the highest
voltage setting provides the consumer with load current.
• If load resistance is continuously reduced, load current is
consistently increased.
• When load current at the initially loaded output reaches the
selected setpoint value ISET, current regulating is activated for this
output.
• If load resistance is further reduced, current regulating reduces
output voltage until the voltage value for the output with the next
lowest setting has been reached.
• As of this point in time, the corresponding KONSTANTER supplies
a portion of the load current.
• This process continues until the output with the lowest voltage
setting is reached.
• This output maintains constant voltage at the consumer. If this
output is also used for current regulation, load current is held
constant as a cumulative current from all parallel connected
outputs until short-circuiting occurs.
Figure 5.8.1 b Direct parallel connection with an ideal working range for
voltage regulation at the consumer
Figure 5.8.1 c U / I Diagram for Direct Parallel Connection
Notes
• Slightly varying voltages result at the individual outputs due to
setting tolerance.
If large voltage differences prevail, an electronic sink becomes
active at the outputs with the lower voltage settings.
The sink attempts to achieve the lower voltage value - possibly
in pulsating mode.
Neither the KONSTANTER nor the consumer are damaged during
this process.
If load current measurement problems should occur as a result,
the devices should be parallel connected for master-slave
operation (see also chapter 5.8.2).
• The outputs can be activated and deactivated simultaneously by
connecting the SIG1 outputs to the TRG inputs (see also chapter
5.8.2).
SLP-KONSTANTER
SLP-KONSTANTER
SLP-KONSTANTER
Settings
USET = Uset
ISET1+2+3=Iset
OUTPUT ON/OFF
+SENSE
-OUT
-OUT
-SENSE
Analog Interface
SIG1 OUT
SIG2 OUT
TRG IN –
TRG IN +
+ 15 V
AGND
Uset -
Uset +
Iset +
U-MON
I-MON
+OUT
+OUT
Settings
USET = Uset
ISET1+2+3=Iset
OUTPUT ON/OFF
+SENSE
-OUT
-OUT
-SENSE
Analog Interface
SIG1 OUT
SIG2 OUT
TRG IN –
TRG IN +
+ 15 V
AGND
Uset -
Uset +
Iset +
U-MON
I-MON
+OUT
+OUT
Settings
USET = Uset
ISET1+2+3=Iset
OUTPUT ON/OFF
+SENSE
-OUT
-OUT
-SENSE
Analog Interface
SIG1 OUT
SIG2 OUT
TRG IN –
TRG IN +
+ 15 V
AGND
Uset -
Uset +
Iset +
U-MON
I-MON
+OUT
+OUT
Load
= Only required for sensing mode operation
Output
Output
Output
I
1
I
2
I
3
I
1
I
2
Σ I
I
1
I
2
U
3
U
3
I
1
I
2
I
3
I
out1
+I
out2
+I
3
I
3
U
3
R
L
------ I
out1
I
out2
+()–=
U
out1
U
out2
U
out3
U
A
/V
I
out1
I
out2
I
out3
I
A
/A
Ideal working range for
voltage regulation at
the consumer
R
L
R
L
Ideal working
current
regulation at
range for
I
out1
I
out2
+
U
3
R
L
------
I
out1
I
out2
I
out3
++≤<
the consumer