Sony KV-32XBR400, Руководство по обучению

Страница: 15 / 95

11
Top & bottom
lines bowed in
(exaggerated)
V Pin
Distortion
Overall Block
The only conventional block within this TV is the vertical block. The re-
maining blocks are different because this TV is a high-resolution type with
a “Wega”® flat screen. Therefore, changes to the power supply, horizon-
tal frequency, convergence, focus, and video processing support the im-
proved picture.
Power Supply
The power supply is in three parts to divide the load on the boards:
Power Supplies
Board Purpose
Standby A Outputs Standby 15V, 7V, & 5V.
Primary Power
Supply A Outputs Set 9V, Set 5V, & Set 3.3V to local
parts on the A, B, & BD boards. Outputs
Pri-Pre 15V to start the Secondary PS.
Secondary
Power Supply D O200V, +135V, +24V (audio), Main
12V, Main 9V, & Main 5V to the D board.
The Primary power supply starts the secondary supply using a Pri-Pre
15V line. Once the Secondary power supply operates, Main 9V outputs
to start the horizontal and vertical oscillators in Y/C CRT Drive IC201.
Vertical Deflection
In some Sony TV sets, there is no V Drive output the Y/C IC until data and
clock are input. Unlike these TV sets, this IC201’s vertical will output
when power is applied. The sync source is dependent upon whether
progressive, interlace or a sub picture is chosen. The vertical oscillator
output is amplified by IC5004 on the “D” deflection board to drive the DY
deflection yoke.
Vertical Pincushion Correction
As the TV screen becomes larger, the yoke can not perfectly control the
beam at the screen perimeter. An additional coil on the top and bottom of
the CRT neck assembly is fed V Pin correction signal from IC201 and
IC5514. The additional coil eliminates any minor inward/outward bow at
the top and bottom of the picture.
Horizontal Deflection
The higher 33.75kHz horizontal frequency is made by IC201 and fed to
the H Drive/Output stage on the D board. The output stage is fed regu-
lated voltage from the +135V Secondary power supply via the PWM cir-
cuit of IC5002.
The horizontal drive stage not only supplies the H Deflection yoke (H DY)
with scan voltage, but also supplies G2 and filament voltage for the CRT.
A reg200V is also output to supply the RGB output amplifiers on
the C board.
Horizontal AFC pulses from this stage are needed by the convergence
and dynamic focus stages for sync. The AFC pulses are used to start the
HV Converter.
HV Converter
Regulated HV and focus voltage is made by the HV Converter stage. It
uses +200V from the secondary power supply to run and AFC pulses
from the horizontal deflection stage to start.
Horizontal Pincushion Correction
To keep the lines at the left and right of the screen straight, an east/west
(E/W) H pincushion correction signal is made in IC201. The E/W signal is
used to modulate the PWM IC5002 that controls picture width. By chang-
ing the width line-by-line, the left and right sides in the large picture can be
straightened.
H Pin
Distortion
Sides bowed in
(exaggerated)