Inventor
JOHNSTON DAVID F
US31 patents
⚠️ This page may combine multiple inventors who share the name “JOHNSTON DAVID F”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.
VOICE SIGNAL TECHNOLOGIES INC
7 patentsUS7526431B2Apr 28, 2009
Speech recognition using ambiguous or phone key spelling and/or filtering
VOICE SIGNAL TECHNOLOGIES INC66 citations97
US7313526B2Dec 25, 2007
Speech recognition using selectable recognition modes
VOICE SIGNAL TECHNOLOGIES INC68 citations96
US7225130B2May 29, 2007
Methods, systems, and programming for performing speech recognition
VOICE SIGNAL TECHNOLOGIES INC99 citations96
US7809574B2Oct 5, 2010
Word recognition using choice lists
VOICE SIGNAL TECHNOLOGIES INC38 citations92
US7716058B2May 11, 2010
Speech recognition using automatic recognition turn off
VOICE SIGNAL TECHNOLOGIES INC20 citations92
US7577569B2Aug 18, 2009
Combined speech recognition and text-to-speech generation
VOICE SIGNAL TECHNOLOGIES INC41 citations91
US7634403B2Dec 15, 2009
Word recognition using word transformation commands
VOICE SIGNAL TECHNOLOGIES INC18 citations84
BHA GROUP HOLDINGS INC
6 patentsUS6839251B2Jan 4, 2005
Apparatus and method for filtering voltage for an electrostatic precipitator
BHA GROUP HOLDINGS INC17 citations89
US6611440B1Aug 26, 2003
Apparatus and method for filtering voltage for an electrostatic precipitator
BHA GROUP HOLDINGS INC39 citations89
US6540812B2Apr 1, 2003
Method and system for improved rapper control
BHA GROUP HOLDINGS INC32 citations88
US5950441ASep 14, 1999
Method and apparatus for controlling an evaporative gas conditioning system
BHA GROUP HOLDINGS INC18 citations88
US6628568B1Sep 30, 2003
System and method for verification of acoustic horn performance
BHA GROUP HOLDINGS INC10 citations72
US5890369AApr 6, 1999
Method for controlling an evaporative gas conditioning system
BHA GROUP HOLDINGS INC4 citations58
JOHNSTON DAVID F
4 patentsUS4605424AAug 12, 1986
Method and apparatus for controlling power to an electronic precipitator
JOHNSTON DAVID F21 citations81
US4483073ANov 20, 1984
Hi jump step saver standard
JOHNSTON DAVID F4 citations62
US4470595ASep 11, 1984
Hi-jack
JOHNSTON DAVID F2 citations62
US4468024AAug 28, 1984
Vaulting pole end plug
JOHNSTON DAVID F1 citations51
NASA
3 patentsBHA GROUP INC
3 patentsUS5068811ANov 26, 1991
Electrical control system for electrostatic precipitator
BHA GROUP INC53 citations91
US5173867ADec 22, 1992
Multiple rapper control for electrostatic precipitator
BHA GROUP INC23 citations88
US5705923AJan 6, 1998
Variable inductance current limiting reactor control system for electrostatic precipitator
BHA GROUP INC14 citations68