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Cassette Style
DC-DC Converters
Q Series
Edition 5/5.2000
17/25
Sense Lines
Important: Sense lines must always be connected!
Incorrectly connected sense lines may activate the over-
voltage limitation, i.e. shutting down the output.
This feature enables compensation of voltage drop at out-
put 1 across the connector contacts and the load lines in-
cluding the diode in true redundant wired-OR system
configurations. In case the sense lines are connected at the
load rather than directly at the connector, the user must
ensure that
Uo P min (between Vo1+ and Vo1–) is not
exceeded. For output voltages
Uo > Uo tr max, the minimum
input voltage according to:
Electrical Input Data increases
proportionally to
Uo/Uo tr max.
Applying generously dimensioned cross-section load leads
avoids troublesome voltage drop. To minimize noise pick-
up, wire sense lines parallel or twisted. For unsymmetrical
loads it is recommended to connect the sense lines directly
at the female connector.
Fig. 24
Sense lines connection for redundant (n + 1) or parallel
operation using wired-OR diodes
Load
Vo2+
Vo1–
Vo2–
S–
S+
Vo1+
T
Vi–
Vi+
i
Vo2+
Vo1–
Vo2–
S–
S+
Vo1+
T
Vi–
Vi+
i
Double
output
Double
output
06097
load
Vo1+
Vo2–
Vo1–
S–
S+
Vo2+
Double
output
Vi–
Vi+
i
Out OK –
Out OK+
Vi–
Vi+
i
Out OK –
Out OK+
+
i
+
–
Vo1+
Vo2–
Vo1–
S–
S+
Vo2+
Double
output
R p
06114
T
Fig. 25
Parallel connection of several modules with series con-
nection of outputs
To ensure correct operation, both sense lines must be con-
nected to their respective power output potential. With dou-
ble output units the sense lines must be connected to out-
put 1 only. Caution should be exercised when outputs are
series-connected as the compensated voltage is effectively
doubled (refer to:
Electrical Output Data). The voltage dif-
ference between any sense line and its respective power
output pin (as measured on the connector) should not ex-
ceed the following values at nominal output voltage.
Table 11: Voltage compensation allowed using sense lines
Output
Total voltage difference between sense
voltage
lines and their respective outputs
5.1 V
<0.5 V
12, 15, 24 V
<1.0 V