Fig. 2.4 Windings Of Transformer - Epson MX-80 Technical Manual

The AC 115, 220 or 240V from the power line first flows through fuse F1 (2A for 115V,
315 rnA for 220/240V) and enters the double-throw power switch. Between this line and
ground, three noise suppressing capacitors C 1, C2 and C3 are connected. The capaci-
tors function to filter the line noise from the power source as well as the noise from the
printer to the power line, so that the digital circuits within Printer are not affected by
external noise and any noise from the Printer does not leak out to external lines.
(2) Power
~upply
circuit
In this ~ircuit. the AC 115, 220 or 240V from the primary side is lowered by the power
transformer to produce voltages required for the control circuit board, driver circuit
board and optional circuit board, respectively. Fig. 2.4 shows the windings and
input/output voltages of the power transformer.
11SV Brown
*(220V Yellow
240V Orange"
0-----.
(Primary)
ovo
a
White
E
0 ' - - - - - - - - '
11S.3V Blue:
I
9V Gray:
I
9.SV Red:
123V
orang~
Green/yellow (for 11 SV only)
Fig. 2.4 Windings of Transformer
(Secondary)
NOTE: The fourth pin (marked with "2") of the S-pin connector on the primary side is used for selection of
220/240V. For 220V, ipsert the yellow wire into the fourth pin and the orange wire (240V) not used into the
fifth pin (marked withl "3")
!
The voltages
lower~d
by the power transformer are converted into required voltages by
the rectifier and cO(1stant-voltage circuit. Fig. 2.5 shows the connection diagram of the
rectifier and const~nt-voltage circuit.
CN)
If
REV. A
".
'"
'" "
CN,
A.IQ'JI.
c. ,
-----------------0 '
~=====::go
:
- - - - - ----0 5
""----------0 '
."
L - - - _ + - t _ _ _ _
-+-_______________
~
."
"
o.
~----+-------------------~~
~~~
+5~+5
L----------========~==========~o ;:~
Fig. 2.5 Rectifier and Constant-Voltage Circuit
2-10
CN'
" 1
CNS
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ir'
" leNS
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