Abstract: A referencing scheme provides a thermal interface between a heat sink and chips within a MultiChip Module (MCM). The referencing scheme comprises a heat sink with a support ring that penetrates a trough formed within a substrate of the MCM. A thermal transfer medium positioned between the heat sink and the chips forms a thermal interface having a low thermal resistance. This cools the chips and ensures reliable operation of the MCM. The trough is filled with a curable adhesive, securing the heat sink to the substrate of the MCM.
Abstract: A low cost shielded transducer cable provides electrical connection between an ultrasound transducer and a display processor. A wound transducer cable is constructed in a first embodiment using two layers of stripline assemblies helically wound in opposite directions around a flexible core. The layers of stripline assemblies are covered with a single metal braid and then coated with insulation. In a second embodiment a stripline transducer cable is formed from a stack of parallel stripline assemblies that may be coextruded with an insulating jacket. In a third embodiment a ribbon transducer cable is formed from a stacked arrangement of parallel ribbon cables and conducting shields that may be extruded in an insulating material.
Type:
Grant
Filed:
March 31, 1995
Date of Patent:
September 3, 1996
Assignee:
Hewlett-Packard Company
Inventors:
Paul Cartier, Wojtek Sudol, Gregory G. Vogel
Abstract: A method and apparatus for correcting flow and pressure sensor drift in a gas chromatograph. At a convenient time when the chromatograph is not being used for analysis, the input valves controlling the input into the chromatograph are shut, reducing internal flow to zero. The indicated rate of flow is then measured using the flow sensor. If the value measured by the flow sensor during this test is different than the originally calibrated offset by some predetermined amount, then the newly measured value replaces the stored offset value. In a chromatograph where some minimum internal gas or liquid flow is necessary to prevent contamination of the instrument, a three-way valve can direct liquid or gas flow away from the flow sensor during this calibration run without eliminating internal flow through the chromatograph. To calibrate the pressure sensor, the pressure sensor is vented to ambient air pressure and its reading at that pressure is then used as an offset during later sample analysis.
Abstract: An I/O circuit that provides bidirectional signal access to an integrated circuit (IC) core has voltage transformation capability to manage different voltage requirements. Although the I/O circuit and the core are fabricated from the same IC process, the I/O circuit can operate at non-process constrained voltages. The I/O circuit provides an output signal at the necessary voltage level to drive a component in the discrete environment while limiting the voltage supplied to the IC core to the maximum device voltage defined by the selected process.