Cr Motor Driver Circuit; Reset Circuit - Epson Stylus COLOR 670 Service Manual

EPSON Stylus COLOR 670

2.2.2.4 CR Motor Driver Circuit

Motor driver IC (IC13) on C301MAIN board drives CR motor.
Stylus COLOR 670 uses 4-phase 200-pole hybrid type stepping motor and
performs constant current bi-polar drive.
ASIC (IC2) converts CR motor phase control signal to LB11847 micro step
drive form and outputs to motor driver IC (IC13) LB11847 from port 93, 105.
Based on this signal, IC13 determines the phase mode.
The current value on each phase is determined by ASIC (IC2) and outputs
from port 95 - 112 to driver IC (IC13). Motor driver IC generates motor driver
waveform based on these input signals and controls the motor.
Figure 2-16. CR Motor Driver Circuit Block Diagram
Operating Principles

2.2.2.5 Reset Circuit

Reset circuits consist of reset/ timer IC (IC5) and peripheral elements. Reset
circuits are attached on the C301MAIN board to monitor the two voltages: +5V
for the logic line and +42V for the drive line. When each circuit detects
abnormality on the corresponding line, it outputs a reset signal to reset CPU
(IC1) and ASIC (IC2). This function is necessary to prevent the printer from
operating abnormally. This IC monitors both +5V and +45 lines but can reset
them independently. The reset circuits outputs reset signal when +5V line
becomes 4.3V or lower or +42V line becomes 35.5V or lower.
Reset ICs have built-in timer function, which manages timer control based on
lithium battery.
Main signal lines are explained below;
n
RST:
n
CE:
n
VIN:
n
VDD:
n
VBK:
n
DATA:
Electrical Circuit Operating Principles
IC5
RTC-9810SA
/ VD T
+42 VI N
+5V VD D FR ST
/ R ST
B A T1
C E
VB K
SC LK
GN D
D A TA
Figure 2-17. Reset Circuit Block Diagram
Reset line
Chip enable line
+42V line supervising line
+5V line supervising line
Lithium battery backup voltage line
Timer data line
Revision A
IC1
HD64F2328F
/ R ES
81
IC2
E05B570**
10 140
/ N M I
3
128
M R ES
2
136
/ R ESET
TC E
TC LK
TD A TA
op05
49