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Circuit Descriptions, Abbreviation List, and IC Data Sheets
9.2.1
Basic Description.
T0 - T1
Deflection T0-T1
Vbatt
Line transistor
CONDUCTS
DMV1500M
140V
7405
BU2520DX
F418
0V
3416
0V
47R
*
F419
GND_HOR
6471
E/W
7406
D
27V
3425
G
82K
I
S 0V
3434
4V8
I499
2K2
I415
Figure 9-2 Deflection T0 - T1
At switch on of the TV set Scap (2417/2418) is charged by
Vbatt. At T0 line transistor 7405 starts conducting. Now the
current flows as shown in figure (T0 - T1), as a result of which
the horizontal deflection will bend the electron beam from the
centre of the screen to the right. Note that the deflection current
has an almost linear waveform.
5
1
5455
NC
9
2
7
4
HORIZONTAL
1
DEFLECTION
COIL
2
4
2
1
3
*
I473
4
4
1
1
2
3
3
2
GND_HOR
3473
T0
T1
F_15040_047.eps
040405
T1 - T2
Deflection T1-T2
Vbatt
Line transistor
OPENS
7405
BU2520DX
F418
0V
3416
0V
47R
E/W
7406
D
27V
G
S 0V
4V8
I499
T
At T1 line transistor 7405 is switched off and the line fly-back
starts. When the line transistor stops conducting, the line
current is at its maximum level. The current charges fly-back
capacitors 2412 and 2413, and also capacitor 2414. This
causes a decrease of line current. (Note that this current has a
half-cosine waveform). The deflection position (i.e. the electron
beam) is in the middle of the screen now.
ES1E
5455
9
7
HORIZONTAL
DEFLECTION
COIL
DMV1500M
*
140V
I473
4
*
F419
3
GND_HOR
6471
3473
3425
82K
3434
I
2K2
I415
T0
Figure 9-3 Deflection T1 - T2
9.
EN 89
5
1
NC
2
4
1
2
4
2
1
3
4
1
1
3
2
2
GND_HOR
T
T1
T2
F_15040_048.eps
040405
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