Epson LQ-2550 Technical Manual page 135

CR Motor Phase Switching System
The CR motor is a 4-phase stepper motor, and each phase is controlled by the corresponding terminal
(AO1 to DO1) of the MCU (4 B). Two phase switching systems are used; 2-2 phase switching and 1-2
phase switching. One step of the 2-2 phase switching system corresponds to two steps of the 1-2
system. Figure 2-83 shows the CR motor phase switching timing. Table 2-54 shows the relationship
between the CR motor speed and the phase switching system.
( 4 B ) CO1 o;;
Step
Rotation
Step
Rotation
— — — —
N
'
I
OFF
1
1
I
I
N
'
OFF
ON
OFF
I
2 3
1
2 Phase Excitation
(a)
I
L
2 3
1
(b) 1-2 Phase Excitation
Figure 2-83. CR Motor Phase Switching Timing
— — —
"
I
I
1
I
I
I
I
I I I
4 6 7
(Carriage moves left to right.)
I
4 5 6 7
(Carriage moves left to right.)
2-89
I
I
8 1
I