Main Motor; Main Motor Drive - Toshiba e-STUDIO350 Service Manual

10.3

Main Motor

10.3.1 Main motor drive

The main motor consists of the motor and the drive board combined with the motor, and its rotation is
controlled by control signals (three) and reference frequency.
LGC board
CN318
(MAMCK)
MAMPL
MAMCW
MAMBK
MAMON
24v
10
(1) LGC board outputs the control signals for the main motor rotation. (MAMCW: Motor rotation direction
setting, MAMON: Motor rotation command)
(2) The excitation phase switching section excites each phase of the main motor. → The main motor is
rotated.
(3) Hall elements A, B and C detect the rotation position of the motor (rotor).
(4) The excitation phase switching section switches the excitation of each phase.
(The motor keeps rotating by repeating from (2) to (4).)
(5) An FG pulse is generated by the FG pattern of the encoder attached to the main motor.
(6) The FG pulse and the reference frequency from the LGC board are compared in terms of the phase
and speed, and the difference is added to the IC1. The fluctuations in the power supply voltage is
also added to the value. (Signal generation)
(7) In accordance with the signal obtained in the step (6), the excitation phase switching section changes
the switching timing.
i.e. The FG pulse and reference frequency are controlled to be equal. → The main motor rotates at a
fixed speed. (Locked range)
(8) When the main motor enters the locked range, the excitation phase switching section outputs the
MAMPL signal to the LGC board. ("L" level)
(9) When the MAMBK from the LGC board becomes "L" level, the main motor is braked. When the
MAMON signal becomes "H" level, the main motor is stopped.
e-STUDIO350/450 DRIVE SYSTEM
Main motor (PC board)
Wave
Phase
correction
comparator
Speed
comparator
Lock
protection
circuit
24v
Voltage
detection
Excitation
circuit
phase Phase W
switching
section
Hall element A
Rotation
Rotor
control
position
detection
Fig. 10-301
10 - 2
Main motor (Motor)
FG pulse
Phase V
Photo-
interuptor
Phase U
Hall element C
Hall element B
November 2003 © TOSHIBA TEC