Epson FX 1170 - B/W Dot-matrix Printer - Page 64

REV.-A
I
I
Primary
I
I
1
I
1
Secondary
1
I
1
Full Wave
Rectification
— Smoothing
Switching
;
Smoothing
<
Circuit
Circuit
Circuit
I Circuit
I
1
1
m
9
Filter Circuit
AC input
I
1
1
I
1
1
1
l------
1
I
1
1
I
I
I
I
1
I
1
1
I
1
1
t
1
+5 v
Switching
Regulator
. . . . . . . . . . . . . . . .
+5V
Over Current
Control Circuit
----..-.....----
+5V
Over Voltage
Control Circuit
I
1
ZD51
Photo-
+35 V Line
coupler
+
Detector Circuit
I
8A
1
1
1
1
I
1
1
1
1
1
I
I
t
t
I
I
I
I
I
I
I
I
1
I
I
I
I
1
t
1
1
1
1
I
{
+5 V Line Voltage
ZD53
Photo-
+
Overload
coupler
Protection Circuit
-
—
.
—
+35 V Line
Voltage Drop
Protection Circuit
.
4 +35 VDC
+ +5 VDC
~ Switch
Figure 2-22. Power Supply Circuit Block Diagram
2-21