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Rugged Environment
AC-DC Converters >100 Watt
T Series
Edition 4/4.99
23/33
MELCHER
The Power Partners.
Storing the System Good Signal
For battery back-up systems located in inaccessible areas
it could be of interest to know, whether there has been a
Power Fail (interruption of the mains). To obtain this infor-
mation Sys Out should be connected to Sys In with a reset
button connected to Vo–. In this way a system failure like an
interruption of the mains will be stored at Sys Out until the
reset button is pressed.
Low Battery Discharge Protection
Since all monitoring functions are powered by the output of
the T unit or the battery in the case of a mains failure, Power
Down can be used to monitor the status of the battery and
to disconnect the load or part of it via the inhibit of the CQ
units when the battery voltage drops below the threshold
level of the Power Down. This prevents further discharge of
the battery. See also:
Power Down.
+
–
+
–
CQ
P
N
P
N
Sys Out
Sys In
T
1740-7DZ
+
–
Vo+
Vo–
Fuse
Vo+
Stored
Sys Out
Reset
R
+
–
HC–
HC+
06084
Temp. sensor
Fig. 44
Storing the System Good signal
Fig. 43
Disconnecting the loads at low battery voltage in case of
mains failure
Fig. 45
UPS uninteruptable power supply system
T
1740-7DZ
CQ
T
1740-7DZ
System
Controller
48 Vnom Power Bus (SELV)
(50.5...56.5 V DC)
Back-up
battery
48 V
12 V, 16 A
(8 A*)
24 V, 8 A
(4 A*)
+5.1 V, 64 A (48 A*)
Power down
DC bus good
Output good
N P
+
–
* For redundancy,
decoupling at the
CQ-outputs with
diodes is required.
Fuse
06085
Temp. sensor
+
–
Out OK–
Out OK+
+
–
CQ
+
–
Out OK–
Out OK+
+
–
CQ
+
–
Out OK–
Out OK+
+
–
CQ
P
N
P
N
Sys Out
Sys In
D
T
1740-7DZ
+ –
i
Vo+
Vo–
D set
Fuse
43.2 k
R
ext
+
R
Vo+
HC+
HC–
–
06083
Temp. sensor