Epson Perfection 1200PHOTO, Service Manual

Page: 22 / 94

EPSON Perfection 1200 Revision B
Operating Principles Power Supply Circuit 22
Figure 2-5. Power Supply Circuit Block Diagram
+ 5 V D C
+ 1 2 V D C
+ 2 4 V D C
A C V o l t g e I n p u t
F i l t e r C i r c u i t
F u l l W a v e
R e c t i f i e r C i r c u i t
S m o o t h i n g
C i r c u i t
S w i t c h i n g
C i r c u i t
S m o o t h i n g
C i r c u i t
+ 1 2 V D C
R e g u l a t o r I C
+ 5 V D C
R e g u l a t o r
C i r c u i t
O v e r C u r r e n t
P r o t e c t i o n
C i r c u i t
S m o o t h i n g
C i r c u i t
+ 2 4 V D C
C o n t r o l C i r c u i t
+ 2 4 V D C O v e r
C u r r e n t P r o t e c -
t i o n C i r c u i t
+ 5 / + 1 2 / + 2 4 V D C
O v e r V o l t a g e
P r o t e c t i o n C i r c u i t
P o w e r S u p p l y
S W
C i r c u i t
P o w e r S W
( P W
- S W )