User manual
GMC-I Messtechnik GmbH 57
5.10 Varying the Internal Output Resistance Value
Functions
In the voltage regulating mode, internal output resistance has a
value of close to 0 .
The internal output resistance value can be increased for certain
applications, for example simulation of long output cables or
weak automotive batteries. The selected (open-circuit) output
voltage is reduced in proportion to increasing load (Figure 5.10a).
Figure 5.10a Output Voltage Relative to Load
Standardization
The standard characteristic curve shown in Figure 5.10b is valid
for all KONSTANTER models.
Quick and easy determination indicating which output resistance
R
i
correlates to any given control resistance R
ext
is made possible
with the curve.
R
i
= R
imax
display value
80 V models:
52 V models:
Figure 5.10b Standardized Curve for Determining Internal Output
Resistance for a Specified Control Resistance
Connection
Connect the analog interface as shown in Figure 5.10c.
The following relationship between internal resistance R
i
and
control resistance R
ext
applies with this wiring configuration:
80 V models:
52 V models:
Example: U
nom
= 80 V, I
nom
= 25 A, R
i
is 0.5
===> R
ext
= 186.108 k
Figure 5.10c Wiring for Varying Internal Resistance
Table o f R
imax
Values for All KONSTANTER Models
Unom
Inom
U/V
I / A
Iset
Uset
0
R
L
R
L
R
i
m
a
x
R
e
x
t
=
0
R
i
m
i
n
R
e
x
t
R
e
x
t
R
imax
= 1.281
U
nom
I
nom
R
imax
25.68 k
R
ext
+25.68 k
R
i
=
;
R
imax
= 1.251
U
nom
I
nom
R
imax
24.82 k
R
ext
+24.82 k
R
i
=
;
R
i
/ R
imax
0.8
0.6
0.4
0.2
R
ext
0 20406080 100
[k]
1
Device Type R
imax
()
62 N 52 RU 25 P 2.602
62 N 52 RU 50 P 1.301
64 N 52 RU 100 P 0.651
64 N 52 RU 150 P 0.434
62 N 80 RU 12.5 P 8.198
62 N 80 RU 25 P 4.099
64 N 80 RU 50 P 2.05
64 N 80 RU 75 P 1.366
U
nom
I
nom
33.12 k
R
i
R
ext
=
– 25.86 k
U
nom
I
nom
31.04 k
R
i
R
ext
=
– 24.82 k
Analog Interface
+15 V
AGND
TRIGGER +
TRIGGER
Uset +
Uset GND
M/S Uset +
Settings:
Load
SSP KONSTANTER
SENSE
+SENSE
U-MONITOR
Iset +
Iset GND
+OUT
I-MONITOR
–OUT
R
ext