Circuit Descriptions, Abbreviation List, and IC Data Sheets
9.
9.3
Display Supply
9.3.1
32" Sets
The 32" sets in this chassis come with a serviceable Display
Supply Unit. This supply unit delivers the power for the display,
AmbiLight unit and the optional panel (bold-on) for Dynamic
Frame Insertion (DFI). Refer to chapter “Circuit Diagrams and
PWB Layouts”, diagrams A1 and A2.
The power supply for the SSB and Audio part are located on
the SSB itself (on-board Platform Supply). For a description,
refer to Section “On-board Platform Supply”.
The supply unit delivers the following voltages to the chassis:
•
12 V for bold-on panel (optional), LCD panel and AmbiLight
(optional)
•
15 V for AmbiLight
•
24 V (or 295 V in case of scanning backlight) for lamp
inverters.
For a block diagram see figure ”Block diagram Display Supply
32" sets”.
Figure 9-5 Block diagram Display Supply 32" sets
A Power-Good circuitry is built around items 7013 and 6024.
The so-called POWER-GOOD line indicates the correct
functioning of the 12 V supply. The voltage on this line is 5 V if
the voltage on the 12 V output is > 10 volt. Refer to figure
“Power-Good circuitry”.
Figure 9-6 Power-Good circuitry
The output voltages of +12 V, +15 V, and +24 V (or +295 V in
case of scanning backlight) are generated through a so-called
resonant DC-DC power converter (LLC-converter) (item no.
7005 to 7008 in diagram A2).
An over-voltage protection circuitry is built around item no.
6020 and 6009 and will activate if the feedback circuitry is
defective (see diagram A2).
A primary over-current protection circuitry is built around item
no. 3055 and 2047 and will activate in case the MOSFETS
(item no. 7005 and 7006) are short-circuited. A secondary
over-current protection circuitry is built around item no. 2014
and 3021 and will activate a soft-start if a short-circuit is
detected in the 12 V and 24 V secondary circuits. See diagram
A2 for details.
The following signals interface with the SSB via connector
1P11 (see diagram A1):
•
DIM-control: adjusts backlight intensity (pulse-width
modulated signal of 3.3 V).
•
Power-Good.
•
Light on_off: switches the LCD backlight (0 - 3.3 V).
•
Boost (fixed: ór 3.3 V ór left “open” depending on
commercial request or display specification).
•
Stand-by: stand-by signal and 5.2 V from SSB to switch
relay on Display Supply Unit on/off.
H_16800_125.eps
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3
07
8
2K2
RE
S
50V
10
u
2
8
11
GND_COLD
6024
BZX
38
4-C4V7
+12Vd
220R
3
077
701
3
GND_COLD
701
3
BC
8
57BW
+5V2
470R
3
076
F407
POWER-GOOD
H_16
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00_126.ep
s
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