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Horizontal Focus Circuit; Microcontroller Cricuit Operation; 1Introduction; Block Diagram - Acer 7299sl Service Manual

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VFOCUS
R420
10K

2.1.26 Vertical focus circuit

This monitor use double focus CRT, so it needs vertical and horizontal parabola focus signal to
input CRT G3 and G5 grid.
The vertical parabola signal is gotten from IC304 pin32 , and amplitued by IC308 and Q404 to obtain
about 200Vpp at the collector of Q404 , via T401 mixed with horizontal signal input FBT focus pack.

2.1.27 Horizontal focus circuit

The horizontal parabola signal is taken from Cs capacitor and amplified by T401 to acquire about
390Vpp amplitude at pin3 of T401 to combine with vertical parabola signal and input FBT focus pack.

2.2 Microcontroller Cricuit Operation

2.2.1Introduction

This model, 7299sl, will support powerful OSD function to help end user fine adjustment. The
Microcontroller circuit of the 7299sl can determine what mode it is by detecting the frequency of
horizontal and vertical synchronous and the polarity of horizontal synchronous, and provide DC voltages
to control the picture and save the adjusted value into the EEPROM by using the OSD, "On Screen
Display control", that means the user can get any information of the picture display or adjust it and save
the status values into the EEPROM by choosing and pressing the proper key according to the indication
of the OSD. In addition, user can press i-key to do auto-calibration.

2.2.2 Block diagram

The major parts of 7299sl Microcontroller circuit are MCU, EEPROM, OSD IC, and Auto Calibration
Module. The circuit block diagram is shown as below.
2-14
R404
C401
15K
47U
IC401
4
50V
3
LM324
+
(EL)
1
-
+
105C
2
11
R405
180K
R403
18K
FIGURE.17 Dynamic Focus Circuit
API Confidential
No Copy/Reproduction Allowed
+24V
T401
19.90046.001
R406
910
3
1
Q404
B1011
4
2
C402
4700P
R407
1KV
68K
(D)
1W
-210V
DAF500V
R408
150
1/2W
C404
0.0068U
R401
400V
10K
(PP)
1/2W
C403
Q405
0.0082U
IRF630
400V
R412
(PP)
47
R410
100K
C405
1/2W
0.1U
50V
(MONO)
RF409
0.22
1/2W
(FUS)
7299sl Service Guided
Fh(Hz) range
FC1
Fh<81K
0
Fh>=81K
1
+12V
R411
10K
Q406
H945
FC1
R413
47K
H-PARA

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