Appeal No. 95-5121
Application 08/018,575
1. Apparatus for commutation of a brushless motor
having encoder means comprising a plurality of Hall-effect
sensors operative for providing commutation information to a
motor controller, the apparatus comprising an output drive
section which includes three high-side power P-channel FETs and
three low-side power N-channel FETs connected to determined
stator windings of the brushless motor; a low-side pre-drive
circuit operative to selectively turn on each of the low-side
FETs and a high-side pre-drive circuit operative to selectively
turn on each of the high-side FETs; a commutation decode logic
circuit; an oscillator connected to the commutation decode logic
circuit for providing a clock signal thereto; and, said
commutation decode logic circuit being connected to the Hall-
effect sensors to receive the commutation position information
from the Hall-effect sensors and being connected to the high-side
and low-side pre-drive circuits for providing selection signals
for selecting the appropriate power FETs for commutating the
motor, the apparatus also including an overcurrent detection and
current limiting circuit connected to the low-side power FETs to
monitor current through the motor.
The Examiner’s Answer cites the following prior art:
Melocik et al. (Melocik) 4,514,665 Apr. 30, 1985
Reinhardt et al. (Reinhardt) 4,724,347 Feb. 9, 1988
Volz et al. (Volz) 4,843,288 Jun. 27, 1989
Gerschner et al. (Gerschner) 4,982,143 Jan. 1, 1991
Yaguchi 5,051,672 Sep. 24, 1991
Sei et al. (Sei) 5,216,293 Jun. 1, 1993
Le 5,258,696 Nov. 2, 1993
OPINION
Claims 1, 4, 5, 7, 8, 11, 12 and 14 stand rejected
under 35 U.S.C. § 103 as unpatentable over Le in view of Volz,
Reinhardt, Sei, Melocik, and Yaguchi. Claims 6 and 13 stand
rejected under 35 U.S.C. § 103 as unpatentable over Le in view of
Volz, Reinhardt, Sei, Melocik, Yaguchi and Gerschner.
2
Page: Previous 1 2 3 4 5 Next
Last modified: November 3, 2007