Qls 21M62US (CHASSIS: NX56-LA), Руководство по обслуживанию

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STMicroelectronics Confidential 7/14
STV8172A Application Hints
4.2 AC-Coupled Applications
In AC-coupled applications (See Figure 6 ), only one supply (V
S
) is needed. The vertical position of
the scanning cannot be adjusted with input bias (for that purpose, usually some current is injected
or sunk with a resistor in the low side of the yoke).
4.2.1 Application Hints
Gain is defined as in the previous case:
Choose R
1
then either R
2
or R
3
. For good output centering, V
7
must fulfill the following equation:
or
Figure 6: AC-coupled Application
R
3
+Vs
R
2
R
1
Rd(*)
Yoke
Ly
(*) recommended:
Ly
50
m
s
------------- Rd
Ly
20
m
s
------------- < <
0.1μF
C
F
(47 to 100μF)
Power
Amplifier
Flyback
Generator
Thermal
Safety
470μF
Output
Current
Output
Voltage
I
p
7
3 2
5
6
1
4
V
M
V
m
+
-
C
s
R
4
C
L
R
5
0.22
μ
F
1.5
W
I
p
V
M
V
m
–
2
------------------------
R
2
R
1
R
3
´
----------------------
´
=
V
S
2
-------- V
7
–
R
4
R
5
+
----------------------
V
7
V
M
V
m
+
2
------------------------
–
R
3
--------------------------------------
V
7
R
2
------- + =
V
7
1
R
3
-------
è
æ 1
R
2
------- +
´
1
R
4
R
5
+
----------------------
ø
ö
V
S
2 R
4
R
5
+
( )
------------------------------
V
M
V
m
+
2 R
3
´
------------------------ +
è ø
ç ÷
æ ö
= +