Inventor · Raleigh, NC, US

Roy S. Colby

30Patents
11h-index
25Co-inventors
75Inventor score

Filing activity: Nov 19, 1993 → Mar 20, 2020

Most-cited inventions

PatentTitleAreaCited byStatus
US7183667B2 Method and apparatus for power inverter synchronization Electricity 185 Expired
US5929400A Self commissioning controller for field-oriented elevator motor/drive system Electricity 84 Expired
US5379864A Magnetic system for elevator car lateral suspension Performing Operations; Transporting 29 Expired
US6163472A Elevator DC motor drive with unity power factor, including regeneration Emerging Cross-Sectional Technologies 26 Expired
US7015597B2 Power regulator for power inverter Emerging Cross-Sectional Technologies 24 Expired
US7570074B2 Electronic overload relay for mains-fed induction motors Electricity 16 Active
US5883344A Automatic calibration of field-oriented elevator motor drive parameters using standstill motor measurements Electricity 15 Expired
US5880415A Automatic calibration of current regulator control compensation for an elevator motor drive with locked rotor Performing Operations; Transporting 14 Expired
US5814774A Elevator system having a force-estimation or position-scheduled current command controller Mechanical Engineering; Lighting; Heating 13 Expired
US7079365B2 Electrical fault detection system Electricity 13 Expired
US5909018A Automatic fine-tuning of rotor time constant and magnetizing current in field-oriented elevator motor drive Performing Operations; Transporting 12 Expired
US7769552B2 Method and apparatus for estimating induction motor rotor temperature Electricity 11 Active
US5880416A Automatic calibration of motor speed loop gain for an elevator motor control Performing Operations; Transporting 10 Expired
US8102140B2 Method and apparatus for estimating induction motor electrical parameters Electricity 10 Active
US6452360B1 Auto tuning and parameter identification of a control circuit Electricity 9 Expired
US8800309B2 Method of automatically detecting an anomalous condition relative to a nominal operating condition in a vapor compression system Mechanical Engineering; Lighting; Heating 9 Active
US7680234B2 Method and apparatus for signal phase locking Electricity 8 Active
US5821656A Magnetic bearing with reduced control-flux-induced rotor loss Mechanical Engineering; Lighting; Heating 7 Expired
US8035322B2 Methods and apparatuses for estimating transient slip Physics 6 Active
US8373379B2 Methods and devices for estimation of induction motor inductance parameters Electricity 5 Active
US7766231B2 Devices and methods for determining the amount of individual usage of a shared commodity Emerging Cross-Sectional Technologies 3 Active
US11128253B1 Rotor resistance based motor thermal protection Electricity 3 Active
US7112898B2 Real-time digital voltage sag compensator Electricity 2 Expired
US8131482B2 Methods and apparatus for estimating rotor slots Physics 2 Active
US5896954A Automatic fine tuning of rotor time constant in field-oriented elevator motor drive Performing Operations; Transporting 2 Expired

Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.