05481167 is referenced by 17 patents and cites 5 patents.

A circuit and method for detecting when the back emf of a motor coil passes a predetermined level includes circuitry for providing a voltage proportional to the back emf of the motor coil, and circuitry for providing a voltage proportional to a reference potential. A first bias voltage is added to the voltage proportional to the back emf to produce a first added voltage, and a second bias voltage is added to the reference potential when the back emf of the motor coil is expected to change in a predetermined direction to produce a second added voltage. A comparator produces an output change when the first added voltage becomes larger than the second added voltage at the predetermined level.

Title
Amplifier and method for detecting the bemf of a coil of a polyphase sensorless DC motor
Application Number
843564
Publication Number
5481167
Application Date
May 2, 1994
Publication Date
January 2, 1996
Inventor
Francesco Carobolante
Scottsdale
AZ, US
Mark E Rohrbaugh
Portola Valley
CA, US
Agent
Lisa K Jorgenson
Rodney M Anderson
Richard A Bachand
Assignee
SGS Thomson Microelectronics
TX, US
IPC
H02K 23/00
View Original Source