Abstract: The present invention includes a novel audio recognition peripheral system and method. The audio recognition peripheral system comprises an audio recognition peripheral a programmable processor such as a microprocessor or microcontroller. In one embodiment, the audio recognition peripheral includes a feature extractor and vector processor. The feature extractor receives an audio signal and extracts recognition features. The extracted audio recognition features are transmitted to the programmable processor and processed in accordance with an audio recognition algorithm. During execution of the audio recognition algorithm, the programmable processor signals the audio recognition peripheral to perform vector operations. Thus, computationally intensive recognition operations are advantageously offloaded to the peripheral.

Abstract: The present invention provides a system and method for communicating data between network subsystems over optical fibers using a backchannel probe signal. In one embodiment, the present invention includes an optical network having an optical fiber coupled between first and second optical couplers residing in two different subsystems. A first processing unit is coupled to a first tap of the first optical coupler for providing an optical payload signal, and a second processing unit is coupled to a first tap of the second optical coupler for receiving the optical payload signal. A probe signal transmitter is coupled to a second tap of the second optical coupler for providing a probe signal, and a probe signal receiver coupled to a second tap of the first optical coupler for receiving the probe signal. The probe signal may be used to detect erroneous fiber connections or lossy inter-subsystem fibers.

Abstract: In accordance with the present invention a data processing circuit includes a first data path for processing first data. The first data path includes a first data storage circuit. A second data path is provided for processing second data. The second data path includes a second data storage circuit. A multiplexer having a first input coupled to the first data path and a second input coupled to the second data path receives the stored values. The multiplexer includes a select input coupled to a clock signal. A delay circuit is configured to delay storage of the second data in the second data storage circuit, wherein the first data storage circuit stores the first data in response to receiving a first timing signal, and the second data storage circuit stores the second data in response to receiving a second timing signal.

Abstract: A circuit according to the present invention includes a plurality of data registers each coupled between the output terminal and a data bus. Each data register stores successive data bits received serially from the data bus. The circuit also includes a plurality of output enable signals each coupled to a corresponding data register. Additionally, the circuit includes a mode select circuit to program the plurality of output enable signals to operate in one of a plurality of modes corresponding to a programmable latency period, wherein in a first mode the output enable signals have a first pulse width and in a second mode the output enable signals have a second pulse width greater than the first pulse width. The circuit may be included as part of a memory circuit in a memory system.

Abstract: A voltage controlled current source circuit of the present invention includes first reference current coupled to a voltage control node. A current input of a voltage controlled impedance is reproduced at the voltage control node through a current mirror as a second reference current. The voltage resulting from the action of the first and second reference currents is coupled to a voltage control input of the voltage controlled impedance. In one embodiment, a control voltage is provided to the gate of a transistor. The source of the transistor is coupled to the current input of a second voltage controlled impedance circuit to produce an output current at the drain of the transistor. The second voltage controlled impedance circuit has a voltage control input coupled to the voltage control input of the first voltage controlled impedance and to the voltage control node.

Abstract: A method of constructing a fuel cell includes a sintering technique that improves the structure and performance of the fuel cell elements. The method includes furnishing a fuel cell core comprising trilayers of anode, cathode, and interconnect layers, and trilayers of anode, cathode, and electrolyte layers. Each of the layers has a mixture of the respective anode, cathode, or interconnect ceramic material mixed with processing aid materials including a binder and a plasticizer, and, in the case of the interconnect mixture, optionally a flux. This partially fabricated fuel cell core is sintered to form a monolithic structure, the step of sintering being performed by heating the core at a heating rate of greater than about 40.degree. C. per minute to a sintering temperature of from about 1550.degree. to about 1600.degree. C., maintaining the core at the sintering temperature for a time of from about 5 to about 20 minutes, and cooling the sintered structure.

Abstract: A method for preparing an article from a powder includes the step of providing a partially consolidated mixture of a solid powder and an organic binder system. The partially consolidated mixture is contacted with a stiffening solution comprising a stiffening agent that effects at least partial cross-linking of the organic binder system, and a solvent that dissolves the stiffening agent but not the organic binder system. The binder system is thereafter removed, and the article sintered.

Abstract: A cargo drive unit which, as part of an array of several such units, it disposed in the hold of a vehicle to permit cargo to be moved within the hold. The drive unit derives power from an electric motor to first erect a drive a roller into contact with a load and then to move the load. A hysteresis coupling is disposed between the motor and the roller and functions to limit the force of the roller against the load to be driven by adjusting the excitation current thereto. The hysteresis coupling allows the roller to retract when the current to the coupling is removed and limits shock loading to drive gearing and the motor when excessive loads are applied to the roller.

Abstract: A voltage controlled current source with variable compliance produces a load current through a load impedance where the load current value is substantially independent of the value chosen for the load impedance. The value of the current is substantially proportional to the difference between a first and second input voltage, and is substantially inversely proportional to a value of resistance chosen as a sense resistance. The current source comprises two variable gain instrumentation amplifiers and a resistance means connected in series with the load impedance.

Abstract: A circuit for interfacing switches to a component which allows the positions of the switches to be determined by the component. The component includes an input port and an output port. A switch network which is a parallel combination of two or more series combinations of a resistor and a switch is connected between the input and output port. A capacitor is connected between the input port and ground. The component determines switch positions by outputting a voltage on the output port and determining the time for the capacitor to charge to a predetermined value. Since each series combination has a unique resistance, the position of the switches therein can be determined in accordance with the capacitor charging time.

Abstract: A liquid crystal display system utilizes an optical arrangement which is aligned so that ambient light from the direction of an obersver's view is channeled behind the liquid crystal display to provide back illumination therefor. An illuminator is arranged to provide supplementary illumination for the liquid crystal display as may be required. A photodetector determines when ambient light is inadequate for required display brightness and operates through appropriate control circuitry to turn the illuminator on or off as the case may be and to control the contrast of the liquid crystal display.