Circuit Operation Theory
API Confidential
No Copy/Reproduction Allowed
2-5
2.1.7 H-center CKT
The current flow through the deflection yoke is sawtooth waveform. We can make raster shift left or right
by changing the DC level of the sawtooth waveform. Adjusting the TP4 or TP5 , the voltage across the
D307 or D308 will be changed. So the DC level and H-center will be changed.
TP7
2
1
L303
D307
D308
R310
19.40130.021
20mH
RGP10D
RGP10D
2W
22
HDY
TP5
TP4
DYH+
TP6
Fig 7 H-Center circuit
2.1.8 HV Shutdown Circuit
The IC201 pin2 (XRAY) provides a voltage detector with a threshold. If the voltage at pin XRAY exceeds
this threshold (6.25v typical) the pins HDRV, BDRV, VOUT1 and VOUT2 are floating. When anode
voltage increases, the voltage at FBT (pin3) increases. the voltage at IC201 pin2 increases. The
shutdown voltage is about 28KV.
GND
HPLL2
HSMOD
FOCUS
SGND
VSMOD
ASCOR
SDA
SCL
HUNLOCK
VCC
i.c.
BDRV
HFLB
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
CLBL
HSYNC
VSYNC
VOUT1
VOUT2
EWDRV
VAGC
VCAP
VREF
HPLL1
HBUF
HREF
HCAP
HDRV
BIN
BSENS
BOP
XRAY
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
+
IC201
R218
R217
R216
C204
TDA4854
20K
(1%)
100K
(1%)
16K
(1%)
50V
1U
(EL)
+48V
TP3
TP2
Fig 8 HV- shutdown CKT
2.1.9 Horizontal linearity CKT
7277e Cs control truth table
Frequency range
SC2
SC1
SC0
Cs Capacitor
Fh 36K
0
0
0
C313 +C311+C314+C312
36KFh40K
1
0
0
C313+C314+C312
40KFh50K
1
0
1
C313 +C314
50KFh62K
0
1
1
C313+C311
62KFh72K
1
1
1
C313
Fig 9 Linear circuit