Smith; Dallas F. - US Patent Attorneys and Agents

Attorney: Smith; Dallas F.

Number of patents: 31
Last date: January 23, 2001

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Number	Title	Issue Date
6178178	Switching module for redundant local area network A switching module provides connection of a processor to a redundant local area network. Redundant access units switch control selects the access unit used by the processor based on the status of each local area network. In particular, two 10BaseT Etherne...	01/23/2001
6064241	Direct digital frequency synthesizer using pulse gap shifting technique A direct digital frequency synthesizer includes inputs for a reference clock signal and a control word, and an output for a synthesized clock signal. A phase accumulator coupled to the input for the control word and the reference clock signal has an outpu...	05/16/2000
6058144	Multi-GB/S data pulse receiver A data pulse receiver for detecting and amplifying substantially attenuated data pulses received at gigabit-per-second rates from a differential coupler with outputs having asymmetrical dc characteristics. The receiver, in a preferred embodiment, has grou...	05/02/2000
6040933	Method and apparatus for channel equalization in wavelength division multiplexed systems A method and apparatus for channel performance equalization in wavelength division multiplexed (WDM) systems is disclosed. Performance of the channels is estimated from optical power measurements of each signal transmitted by the channels. The measurement...	03/21/2000
5781770	Method and controller for controlling shutdown of a processing unit A processor shelf controller monitors processor shelf status. On shutdown or reset request either initiated by a central controller or the processor shelf, the processor shelf controller provides at least a first timer that allows the operating processor ...	07/14/1998
5390278	Phoneme based speech recognition A flexible vocabulary speech recognition system is provided for recognizing speech transmitted via the public switched telephone network. The flexible vocabulary recognition (FVR) system is a phoneme based system. The phonemes are modelled as hidden Marko...	02/14/1995
5382838	Digital driver with class AB output stage A low power (10 mW), high-speed (50 Mb/s) digital driver is formed from three analogue components: level shifter to limit the output swing, waveshaper to limit the slew-rate of the output transition, and a Class AB output stage to buffer the signal. The c...	01/17/1995
5376904	Directional coupler for differentially driven twisted line An interface for differentially driven twisted pair cable provides for inductive and capacitive coupling of a differential drive signal to respective conductors of the twisted pair. Two input tracks have a terminating resistor at a far end whose value equ...	12/27/1994
5365205	Backplane databus utilizing directional couplers A backplane databus and bussing method provide multidrop signal distribution using capacitive and inductive coupling of a main signal. A main signal loop on the backplane has a plurality of coupling loops coupled thereto for a respective length LC.	11/15/1994
5365510	Communications system with a single protection loop A communications system is provided having SONET communications channels extending between first and second locations. The channels include pairs of forward and reverse channels for carrying traffic in normal operation between first and second locations a...	11/15/1994
5329252	Slew-rate limited voltage controlled oscillator control voltage clamp circuit A clamp circuit for use in a phase-locked loop clock circuit, the phase-locked loop including a phase detector with inputs for reference clock signal and oscillator signal, a loop filter with an input connected to the phase detector, and a voltage-control...	07/12/1994
5315175	Quasi-differential bus A digital data bus provides common-mode noise immunity equal to approximately one-half that of a fully differentially driven and received bus. For a data bus having n data lines, n+1 lines are provided, the n+1th line being a reference voltage line. The d...	05/24/1994
5295183	Congestion control system for telecommunications A congestion control system is provided which is an enhancement of the dynamic call routing system taught by Szybicki et al. in U.S. Pat. No. 4,284,852. The congestion control system includes two parts, a restrictive control and an expansive control. The ...	03/15/1994
5283707	Inrush current limiting circuit An inrush current limiting circuit includes a power FET switch connected between power source and load and a control circuit. The power FET switch includes one or more parallel-connected power FETs, each having low individual conductive resistances. The c...	02/01/1994
5179303	Signal delay apparatus employing a phase locked loop An apparatus is provided for delaying digital data signals by fixed amounts within an integrated circuit. A delay lock loop includes an adaptive delay line, a phase detector and an integrator. The integrator provides control signals cp, cn...	01/12/1993
5163067	Method and apparatus for decoding Manchester encoded data A receiver for Manchester encoded data includes an autocalibration feedback loop that generates a timing pulse used to recover the clock and data signals. The autocalibration feedback loop includes a first digital delay line sampled by a plurality of D-ty...	11/10/1992
5146121	Signal delay apparatus employing a phase locked loop An apparatus is provided for delaying digital data signals by fixed amounts within an integrated circuit. A delay lock loop includes an adaptive delay line, a phase detector and an integrator. The integrator provides control signals cp, cn...	09/08/1992
5097509	Rejection method for speech recognition A speech recognizer, for recognizing unknown utterances in isolated-word small-vocabulary speech has improved rejection of out of vocabulary utterances. Both a usual spectral representation including a dynamic component and an equalized representation are...	03/17/1992
5077496	Logic tracking interface circuit A logic tracking interface circuit includes a signal comparator, a feedback comparator and a logic gate of the type to be driven by the interface circuit. The mean of the inverting and noninverting outputs of the signal comparator is applied as an input t...	12/31/1991
5046139	Optical receiver for subcarrier frequency division multiplexing signals The optical receiver includes a photodiode, a preamplifier and a length of transmission line. The photodiode may be connected to the preamplifier, either via the transmission line, or directly between the preamplifier and the transmission line, that is, t...	09/03/1991
5023780	Method of operating a packet switching network A method of operating a packet switching network is disclosed in which a Systems Network Architecture (SNA) computer can control a remote terminal cluster controller and terminals coupled thereto via a switched virtual circuit connection to the terminal c...	06/11/1991
5012042	Cable entry device for EMI shielded cabinets A shielded cable entry device allows direct connection to internal equipment using cables fitted with connectors at each end, while maintaining the EMI integrity of the cabinet. Two versions are disclosed. One having two body members and a securing nut. E...	04/30/1991
5006733	Filter control circuit A filter control circuit uses a compound FET as a resistance element. The compound FET includes parallel FETs having different gate widths to provide different drain-source resistance characteristics, which overlap to provide an extended operating region,...	04/09/1991
5001707	Method of providing reserved bandwidth in a dual bus system A method provides reserved bandwidth in a system having dual unidirectional and oppositely oriented buses. The method is intended to enhance the proposed standard, DQDB Metropolitan Area Network. A portion of the bandwidth shared by the stations in accord...	03/19/1991
4993064	Subscriber line interface circuit and transformer therefor northern telecom limited In a SLIC in which loop current is supplied via active circuits, feed resistances via which the active circuits are conventionally coupled to the line are constituted by bifilar resistance wire windings of a ferrite core transformer, which may include a t...	02/12/1991
4977557	Method of providing effective priority access in a dual bus system A method provides effective priority access in a system having dual unidirectional and oppositely oriented buses. The method is intended to enhance the proposed standard, DQDB Metropolitan Area Network. An effectiveness factor K is introduced to enhance t...	12/11/1990
4975910	Method of operating a packet switching network A method of operating a packet switching network is disclosed in which an X.25 terminal or computer can access the network via a public switched telephone network (PSTN) or a circuit switched public data network (CSPDN) in accordance with CCITT standard X...	12/04/1990
4965884	Data alignment method and apparatus A method and apparatus are provided for receiving parallel digital data signals and an aligned frame pulse. The frame pulse occurs at a regular interval which is a multiple of the data clock period. A multiple clock sampling scheme includes sampling the f...	10/23/1990
4950887	Optical fiber interface An optical fiber interface includes a detector assembly, which may include an integral fiber, for detecting an optical signal carried on a single fiber in an outbound direction and a piezo electric transducer or the like for providing relative movement be...	08/21/1990
4930036	Electrostatic discharge protection circuit for an integrated circuit A terminal of an integrated circuit is protected from electrostatic discharge voltages at the terminal by a protection circuit which includes a bidirectionally conductive transistor as a discharge current shunting device. A bidirectionally conductive cont...	05/29/1990
4926009	Apparatus for organizing equipment cables An apparatus, for attachment to an equipment frame, organizes the cables associated with each interface circuit card of the equipment. The apparatus includes a sheet metal panel having an upper slotted flange and a lower cable channel each extending along...	05/15/1990

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Attorney: Smith; Dallas F.