User manual

GMC-I Messtechnik GmbH 55
5.10 Series Connection
If output voltage from a single KONSTANTER is insufficient, or if you
want to generate a voltage, the outputs of several KONSTANTERs
can be connected in series.
Warning!
Maximum allowable cumulative voltage for series
connection is 120 V (or 240 V with grounded neutral
point).
5.10.1 Direct Series Connection
Attention!
!
If outputs with differing nominal values are series
connected, the highest selected current value is present
at all outputs in the event of short-circuit. However, the
internal reverse-voltage protection diode is only rated for
nominal current of the respective device (see reverse
voltage withstand under Technical Data). For this reason,
all current setpoints must be set to the lowest nominal
current value of all interconnected devices.
The ILIM parameter is used to select this setting.
You can also connect a diode (D
e
, Figure 5.10.1 a) in
reverse direction between the terminals of the outputs
with low nominal values. The diode must be capable of
conducting nominal current from the output with the
highest current value.
Functions
 Easiest way to supply the power consumer with more voltage
than is available from a single KONSTANTER
 Easy wiring
 Less suitable for constant current regulating mode
Connection
Figure 5.10.1 a Wiring for Direct Series Connection
Settings
 Deactivate all outputs.
 Adjust current setpoint ISET of all series connected
KONSTANTERs to approximately the same value:
Iset = ISET1 = ISET2 = ISET3 = ISETn
 Adjust voltage setpoints USET such that they add up to the
desired cumulative voltage value Uset:
Uset = USET1 + USET2 + USET3 + ... + USETn
 Activate the outputs.
Functional Principle
 The sum of all individual output voltages is made available to the
power consumer.
 If load resistance is continuously reduced, all of the outputs
deliver the same load current at first.
 When load current reaches the lowest selected current setpoint
value, current regulating is triggered at the respective output.
 If load resistance is further reduced, this output maintains
constant load current until its output voltage has dropped to 0 V.
 If even further reduction of load current occurs, the affected
output is forced by the other outputs to generate a negative
voltage.
 As of approximately 0.5 V, the internal reverse-voltage protection
diode becomes conductive.
 Load current can once again climb, until current regulation is
activated at the output with the next highest current setpoint
value.
 This procedure is continued until load current triggers current
regulating at the output with the highest current setpoint value.
 Current is held constant by this last output until short-circuiting
occurs.
Figure 5.10.1 b U/I Diagram for Direct Series Connection
Note
 The outputs can be activated and deactivated commonly by
connecting the SIG1 outputs to the TRG inputs (see also chapter
5.10.2).
Settings
USET1+2+3 = Uset
ISET = 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
Settings
USET1+2+3 = Uset
ISET = 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
USET1+2+3 = Uset
ISET = 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
USET1+2+3 = Uset
ISET = Iset
OUTPUT on/off
Settings
USET1+2+3 = Uset
ISET = Iset
OUTPUT on/off
Output
Output
Output
D
e1
D
e2
D
e3
SSP KONSTANTER SSP KONSTANTER
SSP KONSTANTER
Ideal working range
for current regulation
at the load
Ideal working range
for voltage regulation
at the load
U
out1
U
out2
U
out3
I
out1
I
out2
I
out3
R
L
R
L