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Inventor

David F. Johnston

Inventor
Poquoson, VA, US

Overview

36→
Patents
1984–2013
Patent span
Performing operations
Primary field (CPC B)

Patents· 36 as inventor

Public. Assignee & technology derived from the patent record. Each patent links to its LexDana page.

B03Cprimary
B03CMagnetic or electrostatic separation of solid materials from solid materials or fluids28%
G10LSpeech analysis techniques or speech synthesis13%
Y10STechnical subjects covered by former uspc cross-reference art collections [xracs] and digests13%
H02MApparatus for conversion between ac and ac, between ac and dc, or between dc and dc, and for use with mains or similar power supply systems5%
A63BApparatus for physical training, gymnastics, swimming, climbing, or fencing3%
B01DSeparation3%
B05BSpraying apparatus3%
F23JRemoval or treatment of combustion products or combustion residues3%
F28CHeat-exchange apparatus, not provided for in another subclass, in which the heat-exchange media come into direct contact without chemical interaction3%
G01NInvestigating or analysing materials by determining their chemical or physical properties3%
PatentTitleYear
8,409,327'Control of grounded surface geometry in electrostatically enhanced fabric filters'20138,404,020'Systems and methods for monitoring a rapping process'20138,356,588'System and method for controlling combustion'20138,007,566'Electrostatic precipitator having a spark current limiting resistors and method for limiting sparking'20118,000,102'Apparatus and arrangement for housing voltage conditioning and filtering circuitry components for an electrostatic precipitator'20117,837,749'System and method for monitoring impact machinery'20107,809,574'Word recognition using choice lists'20107,716,058'Speech recognition using automatic recognition turn off'20107,704,302'Electrostatic precipitator having a spark current limiting resistors and method for limiting sparking'20107,655,068'Method and systems to facilitate improving electrostatic precipitator performance'20107,634,403'Word recognition using word transformation commands'20097,577,569'Combined speech recognition and text-to-speech generation'20097,562,556'Cleaning system and method for continuous emissions monitoring equipment'20097,526,431'Speech recognition using ambiguous or phone key spelling and/or filtering'20097,505,911'Combined speech recognition and sound recording'20097,452,403'System and method for applying partial discharge analysis for electrostatic precipitator'20087,313,526'Speech recognition using selectable recognition modes'20077,225,130'Methods, systems, and programming for performing speech recognition'20076,839,251'Apparatus and method for filtering voltage for an electrostatic precipitator'20056,628,568'System and method for verification of acoustic horn performance'20036,611,440'Apparatus and method for filtering voltage for an electrostatic precipitator'20036,540,812'Method and system for improved rapper control'20035,950,441'Method and apparatus for controlling an evaporative gas conditioning system'19995,890,369'Method for controlling an evaporative gas conditioning system'19995,705,923'Variable inductance current limiting reactor control system for electrostatic precipitator'19985,515,262'Variable inductance current limiting reactor'19965,374,809'Induction heating coupler and annealer'19945,173,867'Multiple rapper control for electrostatic precipitator'19925,068,811'Electrical control system for electrostatic precipitator'19914,891,591'Nonintrusive method and apparatus for monitoring the cure of polymeric materials'19904,860,149'Electronic precipitator control'19894,605,424'Method and apparatus for controlling power to an electronic precipitator'19864,521,659'Induction heating gun'19854,483,073'Hi jump step saver standard'19844,470,595'Hi-jack'19844,468,024'Vaulting pole end plug'1984

Career & activity timeline

Assembled from patent assignee/location history and declaration credentials.

1984–2013Patents assigned to JOHNSTON DAVID F (7)· patent assignee history
1984Based in Riyadh, SA· patent location history
1985–1990Based in Hampton, VA, US· patent location history
1991–1998Patents assigned to BHA GROUP INC (4)· patent assignee history
1994–2005Based in Yorktown, VA, US· patent location history
1999–2005Patents assigned to BHA GROUP HOLDINGS INC (6)· patent assignee history
2007–2010Patents assigned to VOICE SIGNAL TECHNOLOGIES INC (7)· patent assignee history
2007–2010Based in Arlington, MA, US· patent location history
2008–2013Patents assigned to GEN ELECTRIC (7)· patent assignee history
2008–2013Based in Poquoson, VA, US· patent location history

Inventor activity

Assignee and location history derived from the patent record.

Assignees
AssigneePatentsSpan
GEN ELECTRIC72008–2013
JOHNSTON DAVID Fself71984–2013
VOICE SIGNAL TECHNOLOGIES INC72007–2010
BHA GROUP HOLDINGS INC61999–2005
BHA GROUP INC41991–1998
Locations
LocationPatentsSpan
Poquoson, Virginia, US102008–2013
Yorktown, Virginia, US91994–2005
Arlington, Massachusetts, US82007–2010
Hampton, Virginia, US41985–1990
Riyadh, SA31984