3-7
3.3.3 Excitation Sequence
Drive the motor with 1-2 phase excitation. One step of the motor drive signal feeds the thermal paper
0.03125 mm. One dot line is consisted of 4 steps. When the voltage signal shown in Figure 3-5 is input to
the motor drive circuit shown in Figure 3-3, the printer feeds the thermal paper in the normal direction when
the motor is excited in order of step 1, step 2, step 3, step 4, step 5, step 6, step 7, step 8, step 1, step 2, . . . . ,
as shown in Table 3-3.
START
STEP
1st
STEP
2nd
STEP
3rd
STEP
4th
STEP
5th
STEP
6th
STEP
7th
STEP
8th
STEP
PH1
H
L
PH2
H
L
PH3
H
L
PH4
H
L
1 dot-line
MCL1*
1
H
L
MREF
0.1625V*
2
0V
*1: Set MCL1 to "High" while the motor is driven.
*2: 0.1625V during paper feeding/print, 0.225V during auto-loading.
Figure 3-5 Input Voltage Waveforms for the Sample Drive Circuit
Table 3-3 Excitation Sequence
Input Signal
Output Signal
PH1 PH2
PH3
PH4
A
B /A /B
Step
1 H L L L H
OFF
L
OFF
Step
2 H L L H H L L H
Step 3
L
L
L
H
OFF
L
OFF
H
Step
4 L L H H L L H H
Step
5 L L H L L
OFF
H
OFF
Step
6 L H H L L H H L
Step 7
L
H
L
L
OFF
H
OFF
L
Step
8 H H L L H H L L