Patent ID: 7974093

Claim:
A passively cooled modular electronic system comprising: an open-frame chassis having a bottom opening and a top opening permitting ambient air flow there through; a plurality of modules, each module enclosing electrical components and having a heat sink area, the electrical components in each of the modules being in thermal contact with the heat sink area of the module; a plurality of chassis electrical connections on the open frame chassis for removably electrically connecting the plurality of modules to the open frame chassis; a support for holding each module at the inserted position where each module is in electrical contact with one of the plurality of electrical connections and where the heat sink area of each module is aligned with the bottom opening and the top opening; wherein ambient air is permitted to flow from the bottom opening across the heat sink areas of each of the modules and out the top opening to passively cool the electrical components in each of the modules; wherein the plurality of modules are selected from two or more types of modules, each type of module having different electrical components enclosed therein and a different module electrical connection for connecting that type of module to a corresponding type of chassis electrical connection; and wherein the open frame chassis comprises key pins associated with each type of chassis electrical connection, the key pins having an orientation on the open frame chassis unique to each type of chassis electrical connection, the key pins mating with corresponding key holes in the type of module which corresponds to that type of chassis electrical connection.