David B Roberson

US Patent:

7971487, Jul 5, 2011

Filed:

May 2, 2008

Appl. No.:

12/114675

Inventors:

Eric T. Carlen - Roanoke VA, US
David G. Roberson - Christiansburg VA, US
Hiep T. Bui - Roanoke VA, US

Assignee:

Carlen Controls, Inc. - Roanoke VA

International Classification:

G01B 7/16

US Classification:

73760

Abstract:

A linear position transducer reliably and wirelessly tracks rapid motion. The transducer includes a scale, a control head, and a wirelessly-powered read head disposed proximate to the scale. The read head is configured to sense movement between the scale and the read head and to wirelessly communicate position data to the control head. The control head can include a wireless data receiver to receive position data from the read head, an output data driver to communicate with an external device, and a microcontroller to coordinate a data transfer between the wireless data receiver and the output data driver. In addition, the read head can include a wireless data transmitter to transmit position data to the control head, a linear position sensor to sense position along the scale, and a microcontroller to calculate a position measurement from the scale. The microcontroller in the read head can also coordinate a data transfer between the wireless data transmitter and the control head. To provide a complete wireless solution, the linear position transducer also includes a power system to wirelessly transfer energy from the control head to the read head.

US Patent:

53655508, Nov 15, 1994

Filed:

Jul 18, 1991

Appl. No.:

7/732461

Inventors:

David L. Roberson - Forest VA

Assignee:

Pulse Electronics, Inc. - Rockville MD

International Classification:

H04L 2730

US Classification:

375 1

Abstract:

A direct sequence digital spread spectrum receiver acquires and maintains synchronization in a reliable, yet simple manner, even under severe multipath and interference conditions. A sliding correlator and a voltage controlled crystal oscillator (VCXO) cooperate to acquire initial synchronization, and once synchronization is acquired, the VCXO is linearly frequency modulated (FM) for accurate tracking. The difficult problem of keeping the receiver code clock synchronized to that of the transmitter under severe multipath and interference conditions is solved by virtue of a dual switched bandwidth low pass filter section of the tracking circuit, allowing a wide bandwidth for initial acquisition and tracking but once the clocks are aligned, a narrow loop takes over that follows the transmitter closely. A commercially available intermediate frequency (IF) integrated circuit (IC) is used as an amplitude modulated (AM) detector to achieve the large dynamic range required. The IF IC has an internal received signal strength indicator (RSSI) output which is used to demodulate the amplitude variations generated by the tracking circuit.

US Patent:

43429696, Aug 3, 1982

Filed:

Oct 6, 1980

Appl. No.:

6/194681

Inventors:

Richard T. Myers - Lynchburg VA
David L. Roberson - Lynchburg VA

Assignee:

General Electric Company - Lynchburg VA

International Classification:

H01P 502
H01P 700

US Classification:

333 33

Abstract:

Impedance matching between a helical resonator of a helical resonator filter and a circuit connected thereto is accomplished by the provision of a microstrip transmission line including a microstrip stub printed on a printed circuit board, the microstrip stub being short in comparison to the wavelength at the resonant frequency of the filter whereby the microstrip stub assumes the characteristics of an inductive impedance. A first electrical end of the microstrip stub is connected to a first terminal of the helical resonator and to a first terminal of the circuit, and a second electrical end of the microstrip stub is connected to a second terminal of the helical resonator and to a second terminal of the circuit.

US Patent:

63071517, Oct 23, 2001

Filed:

Jun 2, 1999

Appl. No.:

9/324111

Inventors:

David L. Roberson - Forest VA

Assignee:

Ericsson, Inc. - Research Triangle Park NC

International Classification:

H05K 900

US Classification:

174 35R

Abstract:

A technique for reducing low frequency baseband interference noise is disclosed. The low frequency baseband interference noise typically takes the form of low frequency magnetic interference emanating from a power source providing low frequency switching currents. The power source typically has a supply current terminal and an oppositely disposed return current terminal. The technique is realized by enclosing the power source in an electrically conductive sheath, wherein the electrically conductive sheath has an input terminal disposed proximate the supply current terminal and an output terminal disposed proximate the return current terminal. The output terminal is electrically connected to the return current terminal. Also, the electrically conductive sheath has an opening proximate the supply current terminal for allowing access to the supply current terminal.