Appeal No. 1998-1231 Page 9
Application No. 08/729,835
detector 11 determines that the door is moving and supplies
direction signal R to put the door position counter 23 in a
countdown mode. Responsively, counter 23 counts down the
pulses to obtain the current position of the door. When the
current position of the door coincides with a predetermined
deceleration point, a low speed command signal L is sent to
the speed control 9. This causes motor M and door 5 to
decelerate to a low speed. When the door reaches a fully open
position, the door pulse interval monitor 29 detects a
decreased interval between the pulses due to decreased door
speed, and signals state sequencer 24 to generate a stop
command ST to speed control 9, stopping the motor M. Yoshida
further discloses (Figure 2 and col. 2, lines 53-58) that
“tacho generator 7” is coupled to a rotational axis of the
motor M and generates a voltage that will increase and
decrease as the motor M runs at higher and lower speeds.
Speed control 9 (col. 2, lines 66-68) receives output voltage
V from rectifier and ripple circuit 8 (which includes tacho
1
generator 7) at junction 50, which is also connected to
voltage V or V . The motor is thus controlled to selectivelyH L
run at a high speed set by the voltage V or at a low speed
H
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next
Last modified: November 3, 2007