DEC VT220 - Page 179

TO
DYNAMIC
FOCUS
(C3131
VERTICAL
OUTPUT
FROM
VIDEO
-----I VERTICAL
LOGIC PROCESSOR
VERTICAL
1--""'-....,........ WINDINGS
OF
r-- ........ ..J YOKE
'-- __ .--J ASSY
Figure 8-14 vertical Deflection Circuit
Block Diagram
FROM
-12V +12V
FILTER D301 "
IN4004
C308
1 "r-
150V
V-LIN
R308 nR307
47K lOOK
R3()6
562K
R305
221K 1R310
196
33 1/2'11 ,
C305 1---'-------4'1 if---,
JOOPFT C310
4
SOOV 10100V
}
TO/FROM
10 VERTICAL
Fh----------++_ OUTPUT
11
5
E301
TDA 11705
C303
;:;::100
25V
R30i
4.7K
c...2.
J2 R254
PIN
15 f-~lwK ......, __ 8,
r
I ~~'-;""1'-6 ..,.--....,,7R-3~1~4~2:--+----r, ----l )'!f------l
~ 390K I I ~3~~v
1
~EIGHTl I
C304 R303 C306 R309
T
1 -- 250K "r'2200P 820K
150V l00V
I I i
GND c l---L. ........ ----I.--I.-.l..---'-----'-------...L..- ....... GN00
MA<013!>8A
FROM VER IN
VIDEO
LOGiC
Figure 8-15 Vertical Processor Circuit Diagram
The vertical processor circuit
following components/circuits.
(Figure 8-15) consists of the
• Vertical processor device (E301)
• Vertical sync input (R254 and R301)
• Voltage regUlator (D301 and R301)
• Oscillator synChronizer (R302 and C304)
• Current regulation (R303 and R304)
• Ramp sensor (R306)
• Power amp stabilization network (R305, R3l0, C305, C306,
and C310)
• Vertical linearity control (R308, R307, C307, and C308)
8-13