Epson LQ-1170 - Power Supply Board

REV.-A
The +35
VDC line has a voltage overload protection circuit and a voltage drop protection circuit. The
+35 V voltage overload protection circuit cuts the supply if the voltage reaches or exceeds +36
VDC.
It stops switching circuit operation,
which stops the output of the +35
VDC line. The voltage drop
protection circuit protects the printer from damage that might occur if the secondary circuitry
+35
VDC line short circuits. If a voltage drop is detected, it stops switching circuit operation,
stops the output of the +35
VDC line.
of the
which
Power Supply Board
~-
1
1
I
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
I
t
1
1
1
1
1
1
1
1
1
I
I
I
1
1
1
1
1
1
1
--
-----------------------------------------------------------
------------
1
f 1
Prim a ry
i &
! Secondary
t
tt
1
1
1
1
I I
0
Filter
Circuit
-----
------------------
t
AC Input
4-
y
+5 line
I
1
Voltage
Overload
1
Protection
1
Circuit
1
1
1
1
1
1
1
+35 line
1
Voltage
Overload
1
Protection
1
1
Circuit
1
1
I
-D
+5 VDC
1
I
*I
1
1
1
1
I
I
I
1
1
1
1
1
1
1
1
1
----------------------------------------------
J
Power
Switch
Figure 2-16. Power Supply Circuit Block Diagram
2-13