Northern Telecom Limited

Nortel Networks Corporation

John S Moss

Clifford D Read

Pak-Jong Chu

Roman Katchmar

Michal Stefan Tencer

Hugh M Collins

Hasler R Hayes

Geoffrey A Collar

John B Drayton

David J Pell

Tristano F Nicoletta

Michael Reginald Bishop

John Hanmer Watkins

Richard P Hughes

Trevor George Zapach

Paul Douglas McDonald

Anthony J Langenberg

Rodney David Pike

Sei S Hoe

Kevin L Dalgleish

Vincent E Somoza

Gregory R Reinhart

William L Craig

Brian E Voss

Electronic equipment having a temperature control air flow passage. A length of filter material has a length portion extending across the upstream end of the flow passage, the filter material being movable longitudinally to replace the clogged length portion with unused filter material. A filter advancement device is operable by a control device actuated when an undesirably low fluid flow rate is achieved through the length portion so as to effect filter replacement. Roller devices give up unused filter material and take up used material. A stepper motor may be used to advance filter material for replacement purposes. The control device is preferably operated upon drop in rotational speed of a fan located immediately downstream of the filter length portion, the speed drop being caused by drag as the filter becomes clogged. Alternatively, the control device comprises a switch which is operated as the filter length portion flexes it becomes clogged, or temperature sensors located at chosen sites.

Flow rate control of temperature control fluids

The present invention relates to two modules containing electronic equipment, one relatively small, and one relatively large, that will be physically connected and used for extended operation in an environment where the ambient atmosphere contains moisture filled air or some other specified environmental contaminant. An absorber such as desiccant of a prescribed amount is contained within at least the relatively large module to control the absolute humidity and/or environmental contaminants within each module during extended operation in the ambient environment. Permeable wall portions are placed in the region between the relatively small module and the relative large module to allow for moisture and/or other specified environmental contaminants to pass from the relatively small module to the relatively large module. As such, the lifespan of the small module can be extended.

Enhanced humidity control for small modules

The invention relates to a passive liquid immersion cooling apparatus for electronic systems operating in thermally uncontrolled environments. The apparatus comprises an external shell, defining a chamber with a plurality of heat dissipating components disposed within the chamber and surrounded by the shell. The components are immersed into a low boiling point dielectric liquid partially filling the chamber. The shell has two portions, an upper portion of the shell adjacent the area above the liquid level which forms a vapor space, and a lower portion of the shell adjacent the liquid. The shell has an external heat transfer structure providing more efficient heat transfer from the upper part of the shell, for example, in the form of external fins extending outward from the shell, and an internal heat transfer structure in the form of internal fins extending inward from the shell and into the chamber. Preferably, the external fins extend along the upper portion of the shell only. The external heat transfer structure provides effective thermal management of the electronic components within the apparatus over a wide outdoor temperature range. Additionally, a cylindrical design of the apparatus provides more reliable sealing and better pressure containment of the apparatus and may include a solar shield. An assembly of cooling apparatus employing the liquid immersion cooling apparatus and additionally comprising a conduction cooling apparatus, a forced convection cooling apparatus, and a solar shield is also disclosed.

Liquid immersion cooling apparatus for electronic systems operating in

An outdoor wireless base station having a housing and a circuit pack extending upwards in the housing with electronic components extending into a forward air flow passage. The forward air flow passage is interconnected for air circulation with a rearward air flow passage and a heat conductive rear wall of the housing partly defines the rearward flow passage. Air in the forward air flow passage flows upwards and into the rearward air flow passage for heat removal through the rear wall. The cooling air flows downwards in the rearward air flow passage to return to the bottom of the forward air flow passage.

Wireless base station-having cooling passages

Electronic unit of printed circuit board with electronic components on one side and its other side in heat conducting contact with a heat sink enables the electronic components to be sealed from ambient atmosphere and thus unpackaged chips may be used. The units are mountable in a support frame with air cooling passages of the heat sinks extending vertically for convected cooling air. In each unit, a resistor network may extend into a cavity formed in a heat exchange rib and an electronic chip, perhaps unpackaged in the sealed environment, may be in heat conductive relationship with the heat sink.

Electronic unit

Electronic module of printed circuit board with electronic components on one side and its other side in heat conducting contact with a heat sink enables the electronic components to be sealed from ambient atmosphere and thus unpackaged chips may be used. The modules are mountable in a support frame with air cooling passages of the heat sinks extending vertically for convected cooling air. In each module, a resistor network may extend into a cavity formed in a heat exchange rib and an electronic chip, perhaps unpackaged in the sealed environment, may be in heat conductive relationship with the heat sink.

Electronic module

A telephone hook switch uses an elastomeric member as the contact making member. A hook switch has a pivotally mounted actuating member having two levers extending in opposite directions, one on each side of the pivot axis. One lever is moved by the positioning, and removal, of a handset, the actuating member being biased to a particular pivotal direction. The other lever presses on a deformable projection in the elastomeric member. Depression of the projection causes an electrically conducting layer to move into contact with contact areas of a switch position on a printed circuit board.

Telephone hook switch with elastomeric contact member

A circuit pattern on a circuit board, as used in telecommunications systems and other electrical apparatus, often has contact positions for switches, such as pushbutton switches, and for other purposes. The normal copper circuit pattern is covered at the contact positions to give improved contact conditions. Carbon ink has been proposed by obtaining the necessary high level of alignment of carbon ink with the copper pattern at contact positions is difficult as such contact positions have very close members. The invention proposes contact positions having closely spaced inter-digital contact members, in which the circuit pattern extends to and stops at the peripheral region of a contact position, the contact members being of carbon ink and overlapping conductors of the circuit pattern at the peripheral region.

Circuit board with contact positions, as used for telecommunications

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Ottawa, Canada

John S Moss