Inrush Current Control Technology Boosts Power Converter Reliability

Special Feature
baseplate without deratings. The 100-watt
model CN100A24-12, for example, delivers
8.4 amps at 12 VDC with a conversion
efficiency of 88% at full load. These quarter-brick
modules measure 1.45 x 2.28
inches and are only 0.50-inch high.
Meeting SWaP Requirements
Size, weight and power concerns
have become almost equally as impor-
[ 14 ] COTS Journal November 2011
tant as ruggedness in many military applications.
Serving those needs, Martek
Power has made significant additions
to its Powertron JL Series (Figure 3) of
open-frame DC/DC converters. They
are conduction-cooled units developed
by Martek in response to an increase
in applications where the power supply
is mounted inside a sealed enclosure.
Originally designed for onboard pas-
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senger information systems, JL DC/DC
converters are rated up to 50W and offer
full EN50155 compliance as well as the
ability to accept the wide range of typical
railway input voltages. Outputs can be
specified between 5 and 110 VDC, and
the units have a footprint of just 135 x 85
mm including the mounting plate. With
efficiencies approaching 90 percent,
the conduction-cooled versions help to
minimize any temperature rise within
the host equipment. All converters in
the JL Series are designed for continuous
operation at ambient temperatures of up
to 75°C without de-rating.
AC/DC Supplies and UPSs
Closer to the installation side of
military systems, new solutions in AC/
DC and UPS product areas continue to
advance. With its latest AC/DC solution,
RECOM has released a new range of
isolated AC/DC power supply modules
with very low standby input currents,
ideally suited for low-power applications
or standby power supplies. The RAC01
and RAC02 offer 1W or 2W of output
power from a universal input voltage of
90-265 VAC and yet draw only 30 mW
in standby. The RAC03 offers a higher
output power of 3W yet draws only 80
mW when unloaded. Unlike other lowpower
AC/DC modules, the RAC01,
RAC02 and RAC03 offer high-efficiency,
well regulated, short-circuit protected
DC outputs with 3.3, 5, 9, 12, 15 or 24V
voltage options and a line and load regulation
of typically ±2%. The conversion
efficiency is up to 78%, which enables
RECOM to guarantee an operating temperature
range of -25° to +85°C for the
one watt part, reducing to +80°C for the
two and three watt converters.
Moving ahead in the uninterruptible
power supply game, SynQor recently announced
a line of Military-Grade Uninterruptible
Power Supply units that are
designed for the extreme environmental
and demanding electrical conditions of
Military/Aerospace applications. Syn-
Qor’s UPS incorporates field-proven high
efficiency designs and rugged packaging
technologies. This UPS will accept a wide
range of input voltage and frequency values
while delivering a well-conditioned