Printronix L5535, Maintenance Manual

Page: 149 / 358

Motor Rotation Control
II–149
Transfer Elevator Motor
This is a 2-phase 4-pole stepper motor. Its permanent magnet rotor rotates
when pulse signals, which are 90
°
out of phase, are applied to four
electromagnets as shown below. (One pulse provides a step angle of 1.8°.)
The transfer unit moves up or down when the shaft (cam shaft) of this motor
rotates 180
°
(equivalent to 100 pulses) in the normal or reverse direction.
The motor drive sequence is indicated below:
When the transfer elevator motor forward rotation instruction pulse is fed
while the transfer unit is in the lower position, the motor rotates so that the
transfer unit is lifted by cam action. When the transparent vinyl chloride
cylinder installed over the cam shaft rotates, and the tape on the cylinder
surface blocks the light path between the light emitter and receptor of the
transfer unit upper-limit sensor (TUUL), the motor stops. If the motor reversal
(Forward rotation)
1 2 3 4
Pole A 1 1 0 0
Pole B 0 1 1 0
Pole C 0 0 1 1
Pole D 1 0 0 1
(Reverse rotation)
1 2 3 4
Pole A 0 0 1 1
Pole B 0 1 1 0
Pole C 1 1 0 0
Pole D 1 0 0 1