Epson FX-870/1170 All in One Printer User Manual


 
Principles of Operation
Paper Feed Motor Drive Circuit
The PF motor, a stepping motor, advances the paper at a
minimum
advance rate of
l/216
inch. This
motor is a 2-2 phase, constant-voltage, drive motor. CPU ports
(P70
tc
P73)
are used to control the
PF motor. Phase data for the PF motor is output through these ports. PFA to PFB are turned on
or off within the pPA1476H
(ICl),
depending on the phase data sent from the CPU.
-
When there is an output at A19 of the CPU, a +36 V voltage is supplied to the PFCOM terminal
of the PF motor. Otherwise, a
+6
V voltage is supplied through
Dl
to hold the motor.
CPU
UPAl476H
(ICl)
PF
MOTOR
.
4-phase,
48-p
PM-type
pulse
motor
36
VDC
i
10%
61
a
*
3
fi
(per
phase)
(at
77’
F,
26“
C)
Figure 6-28. Paper Feed Motor Drive Circuit
6-28
Epson
FX-87W1170