David A Schmidt

Address:

3328 NW Thurman St, Portland, OR 97210

VIN:

1FT8W3DT6CEA29274

Make:

FORD

Model:

F-350 SUPER DUTY

Year:

2012

US Patent:

7920990, Apr 5, 2011

Filed:

Jul 16, 2008

Appl. No.:

12/174588

Inventors:

Richard B. Nicholls - Portland OR, US
Walter R. Strand - Portland OR, US
Lynne A. Fitzsimmons - Portland OR, US
David W. Schmidt - Portland OR, US
Ronald J. Larrick - Beaverton OR, US

Assignee:

Tektronix, Inc. - Beaverton OR

International Classification:

G01R 23/00
G06F 17/00

US Classification:

702190, 702 68, 702 73, 702 76, 324 7619

Abstract:

Apparatus and methods are provided to allow multiple, possibly overlapping, regions of interest within a frequency spectrum to be defined, and managed. Each of these regions of interest may be selected for further testing or identification. Unselected regions are allowed to collapse into narrow bars so as not to interfere with the selected region. Multiple rows are provided to allow for the definition and selection of overlapping regions of interest. Furthermore, in some embodiments aid is provided for identifying the signal type by providing a list of signal type candidates based upon such parameters as region of interest bandwidth, region of interest center frequency and geographic location.

US Patent:

59398876, Aug 17, 1999

Filed:

Sep 5, 1997

Appl. No.:

8/924753

Inventors:

David W. Schmidt - Portland OR
Gerald S. Harris - Portland OR

Assignee:

Tektronix, Inc. - Wilsonville OR

International Classification:

G01R 2726
H04B 1700

US Classification:

324628

Abstract:

A method for measuring interference in a cable transmission system includes the step of establishing a spectrum frequency measurement window having start and stop frequencies and an amplitude threshold. Data is acquired over the window representative of the spectral energy of the cable transmission system within the window and the data is compared against the threshold value. If the data falls below the threshold value, indicating the absence of a carrier signal within the window, a display is generated characterizing the interference over the window. Additional measurement windows may be established having different start and stop frequencies and thresholds for measuring different portions of the cable transmission system frequency spectrum.

US Patent:

20210109156, Apr 15, 2021

Filed:

Mar 31, 2020

Appl. No.:

16/835450

Inventors:

- Pullman WA, US
David E. Whitehead - Pullman WA, US
Tony J. Lee - Henderson NV, US
David J. Casebolt - Moscow ID, US
Krishnanjan Gubba Ravikumar - Pullman WA, US
David Schmidt - Athens GA, US
Austin Edward Wade - Moscow ID, US

Assignee:

Schweitzer Engineering Laboratories, Inc. - Pullman WA

International Classification:

G01R 31/327
H01H 47/00
H02H 1/00

Abstract:

Systems and methods for testing a protection relay, such as a primary bus protection relay, may include a testing device for providing current signals imitating current on both sides of a bus to the primary bus protection relay. The signals may be provided using signals corresponding with a signal format from merging units or other monitoring devices. The testing device may be configured to receive communications from the primary bus protection relay for evaluation of the operation of the primary bus protection relay.