Thursday, September 14, 2006

VMEbus/CPCI Enclosures withstand extreme environments

Single-slot E118 chassis enclosures provide environmental protection for 6U VMEbus or CompactPCI (CPCI) SBCs against altitude, temperature, humidity, shock, vibration, EMI/RFI, and chemical exposure. Machined from 6061-T6 aluminum, each enclosure accommodates one ANSI/IEEE 1101.2 VMEbus or ANSI/VITA 30.1 conduction-cooled card. Products come with built-in power supply, dc-dc converters, and fully isolated I/O and are protected against disruptive power conditions.

Chatsworth, CA, April 2005 - Comprehensive environmental protection for 6U VMEbus or CompactPCI single board computers is now available in the rugged, single-slot E118 chassis enclosures from Aitech Defense Systems, Inc., a world leader in the development and manufacture of board and subsystem level products for harsh environment defense, aerospace and space applications. Designed to meet the mechanical, electronic, and thermal demands of mobile military applications, these environmentally-sealed units are capable of withstanding extreme environmental conditions of altitude, temperature, humidity, shock, vibration, EMI/RFI, and chemical exposure.

The compact, lightweight enclosures, machined from 6061-T6 aluminum, are available with captive fasteners, as well as optional helical wire-rope-type shock and vibration isolators in bottom assembly or side assembly configurations. They are also available with mounting brackets for hard-mounted configurations suitable for cold-plate applications. For additional environmental protection in a variety of mobile applications, all enclosure finishes are treated for corrosion and fungus resistance.


The enclosures use a fully sealed Faraday cage and complete EMI/RFI power line filtering to protect the electronic integrity of an installed VME or CompactPCI board, and to meet the EMI/RFI emanation and susceptibility limits of MIL-STD-461. The E118 chassis feature metal-to-metal clamping with conductive surfaces and fasteners, conductive O-ring seals, and line feed-through filters on the inner surface of the I/O panel.

The built-in power supply for each enclosure is engineered to provide continuous high current, high efficiency operation even in adverse conditions. Major features include: DC-DC converters designed to operate even with irregular or noisy power sources; fully isolated inputs and outputs to eliminate the possibility of ground loops; plus additional protection against short circuits, over-voltage, reverse polarity, and other disruptive power conditions.

Each enclosure accommodates one standard ANSI/IEEE 1101.2 VMEbus or ANSI/VITA 30.1 conduction-cooled card. Heat is conducted through the CNC machined aluminum sidewalls of the unit and is radiated/convected to the surrounding air by means of external fins on the sides and top walls of the enclosure. Forced-air cooling is not required. Optional base mounting of the enclosure to a cold-plate further enhances the thermal path with external conduction cooling. The specified operating temperature range extends from -46[degrees]C to 71[degrees]C (-50[degrees]F to 160[degrees]F), at 5% to 95% relative humidity with condensation.

Mil-standard connectors, one for input power and up to four circular connectors for I/O, are all located on one side of the enclosure for easy access. A card access panel provides for easy insertion and extraction of VME cards, with an optional hinged and sealed door for convenient access to PCMCIA cards without disassembling the main chassis panels.