K Series
AC-DC Converters >100 Watt
Rugged Environment
Edition 4/4.99
22/28
MELCHER
The Power Partners.
E Inrush Current Limitation
The converters may be supplemented by an electronic cir-
cuit (option E, replacing the standard built-in NTC) to
achieve an enhanced inrush current limiting function.
Table 17: Inrush current characteristics with option E
Characteristics
LK
Unit
Ui = 230 V AC
typ
max
Iinr p
Peak inrush current
–
21.7
A
tinr
Inrush current duration
35
50
ms
Input
Filter
Control
Converter
FET
Ci
RI
RS
Rectifier
PFC
-
Control
1
1001
Fig. 32
Inrush current with option E, Ui = 230 V AC, Po = Po nom
Precaution:
Subsequent switch-on cycles at start-up are limited to
max. 10 cycles during the rst 20 seconds (cold unit) and
at continuing on/off (
TC =95
°C) max. 1 cycle every
8 sec.
Vo+
Vo–
Vo+
Vo–
Load
Vo+
Vo–
11003
Input
Filter
Control
Converter
FET
Ci
RI
RS
Rectifier
PFC
-
Control
1
1001
Fig. 31
Option E block diagram
Fig. 33
An example of poor wiring for connection in parallel
Description of Options
Table 16: Survey of options
Option
Function of Option
Characteristics
-9
Extended operational ambient temperature range
TA = –40...71°C
E
Electronic inrush current limitation circuitry
Active inrush current limitation
P 1
Potentiometer for fine adjustment of output voltage
Adjustment range +10/–60% of
Uo nom excludes R input
D 2
Input and/or output undervoltage monitoring circuitry
Safe data signal output (Versions D0...DD)
V 2 3
Input (and output) undervoltage monitoring circuitry
ACFAIL signal according to VME specs (Versions V0, V2, V3)
T
Current sharing
Interconnect T-pins if paralleling outputs (5 units max.)
B1, B2
Cooling plate
Replaces standard heat sink, allowing direct chassis-mounting
1 Option R excludes option P and vice versa
2 Option D excludes Option V and vice versa
3 Only available if main output voltage Uo1 = 5.1
-9 Extended Temperature Range
Option -9 extends the operational ambient temperature
range from –25...71
°C (standard) to –40...71°C. The power
supplies provide full nominal output power with free air con-
vection cooling. Option -9 excludes inrush current limitation
by NTC.
P Potentiometer
The potentiometer provides an output voltage adjustment
Uo nom and is accessible through a
hole in the front cover. This feature enables compensation
for voltage drops across the connector and wiring. Option P
is not recommended if units are connected in parallel.
Option P excludes the R-function. With double output units
both outputs are affected by the potentiometer setting (dou-
bling the voltage setting if the outputs are in series).
If the output voltages are increased above
Uo nom via R-in-
put control, option P setting, remote sensing or option T, the
output current(s) should be reduced accordingly so that
Po nom is not exceeded.
T Current Sharing
This option ensures that the output currents are approxi-
mately shared between all paralleled modules and in-
creases system reliability. To use this facility, simply inter-
connect the T pins of all modules and make sure, that
pins 14, the S– pins (K 4000) or the Vo1– pins (K 5000) are
also connected together. The load leads should have equal
length and cross section to ensure equal voltage drops. Not
more than 5 units should be connected in parallel. If output
voltage adjustment is requested we strongly recommend to
use the R-input instead of option P, as with option P the re-
quired setting accuracy is difcult to achieve. The output
voltages must be individually set prior to paralleling to
within a tolerance of 1...2% or the R pins should be con-
nected together.