DEC VT220 - Page 173

8.2.2.3 Horizontal Output Circuit The horizontal output
circuit is turned on and off by the horizontal driver circuit to
generate the potential applied to the horizontal windings of the
yoke assembly. The horizontal output circuit potential is also
used to control flyback transformer activity (refer to description
in section 8.2.4).
The horizontal output
components/circuits.
(Figure 8-7)
consists of the following
• Input network (R216 and L200)
• Drive transistor (Q202)
•
Collector voltage network
R218)
(Tl primary, D201, C214, and
• Charge pump circuit (C106, D101, D102, and C105)
• Horizontal linearity (L201, L202, R217, and C212)
• Yoke connector (J1)
• Output components (C2l6, C213, D200, R231, and C224)
-,
I
.~
OF
YOKE
ASSY
PART
OF
Jl
PART OF FLYBACK
TRANSFOMER
(T 11
+12V FILTER TO
DYNAMIC
FOCUS
(Cn3,
5207 r- ~
PUR I ~207 I
5
TO
DYNAMIC FOCUS
102031
TO
HORIZ PROC
(C2071
I TO
f---DYNAMIC
TO
BRiGHTNESS
CONTROL
iR 1 iO
FOCUS
I
(Rn1l
5207 IP207
I
YEL 6
~~'
!
,f
I
I
13006
C106l.
M L200
02 T L201 5207 IP207
I
RIZ
500Y
WIDTH
BRN 7
YER
0101 I
:--- r----
EkJ
' j "" I
R217
~"IA115~~0
RG 1J I
100
..-toI-
1/2W
0200
1:5201
0102,
" L202
C213
A115M
""C215
22
RG1J
;;:
C212
LIN
.022 ,..r:
1000
.1
250V
16v
GND I
CWE
l00Y
""I' C214
R218
I
10 ;;:
470
1
I
250V
16V
3W
i I
-
\ r-
a
2 I
I
C2l6
R231
i
10
270
I
I
25v
*C224
I
6801'
1
lKV
3 I
L
FROM
FRO
HO
ORI
(T20
Figure 8-7 Horizontal Output Circuit Diagram
8-7