Toshiba TW40F80 Horizontal Output Circuit, Operation of Basic Circuit, Fbt, Signal DEF/POWER PCB

Page 68

4. HORIZONTAL OUTPUT CIRCUIT

 

10

 

HV

The horizontal output circuit applies a 15.625 kHz/15.734

 

5

 

 

kHz sawtooth wave current to the deflection coil with mu-

 

2

T461

 

 

FBT

 

tual action of the horizontal output transistor and the damper

 

 

 

 

 

 

S-charactor

diode, and deflects the electron beam from left to right in

 

3

 

capacitor

horizontal direction.

Q404

 

 

 

 

1

8

Deflection yoke

 

H output

(With damper diode)

 

 

(H coil)

IC501

 

 

 

T401

 

 

 

L462

L463

L464

 

 

 

H drive

C440

C343

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R415

transformer

 

D444

 

 

 

 

 

 

 

 

C444

 

 

 

 

 

H. out

 

 

 

 

 

C418

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TP-33

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Q402

 

D461

 

C423

R441

 

 

 

 

H drive

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BB81

 

C463

 

 

 

 

 

H

Q1

23

83

 

 

 

 

 

 

 

 

 

 

 

linearity

 

 

 

 

 

 

 

 

R411

 

C417

C467

 

 

 

 

coil

 

 

R410

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D443

L441

 

 

 

 

 

 

 

 

 

 

 

 

 

C413

 

 

L461

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

To High Voltage

 

 

 

 

 

+

 

 

Regulator Circuit

 

 

 

 

C416

R416

C464

 

 

 

 

 

 

 

 

 

+

 

 

 

 

 

 

 

 

 

Resonat

 

 

 

 

 

 

 

 

 

capacitor

 

 

 

 

 

 

 

 

 

 

To DPC output

 

 

 

 

 

SIGNAL

DEF/POWER PCB

125V

 

 

Diode modulator circuit

Fig. 9-4

4-1. Theory of Operation

4-1-1. Operation of Basic Circuit

(a)H output basic circuit

(1)

To perform the horizontal scanning, a 15.625 kHz/

 

15.735 kHz sawtooth wave current must be flown into

 

the horizontal deflection coil. Theoretically speaking,

 

this operation can be made with the circuit shown in

 

Fig. 9-5 (a) and (b).

(2)

As the switching operation of the circuit can be re-

 

placed with switching operation of a transistor and a

 

diode, the basic circuit of the horizontal output can be

Houtput transistor

D

Co

Damper

Resonant

diode

capacitor

 

 

Vcc

L

Deflection yoke

expressed by the circuit shown in Fig. 9-5 (a). That is,

the transistor can be turned on or off by applying a

pulse across the base emitter. A forward switching cur-

rent flows for on-period, and a reverse switching cur-

rent flows through the diode for off-period. This switch-

ing is automatically carried out. The diode used for

this purpose is called a damper diode.

(b)H output equivalent circuit

SW1

SW2

Co

L

 

 

Vcc

 

 

Fig. 9-5

 

 

68

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Contents TW40F80 Contents Terminal FUNCTION, Description and Block Diagram Wide Aspect Conversion Circuit Failure AnalysisSection X Deflection Distortion Correction Circuit Section XI Digital Convergence CircuitSection Feature Improved ServiceabilityOutline Merits of BUS System Reduction of Parts CountSpecifications Chassis ModelFront View Video 3 InputsRear View IN-VIDEORemote Control View 100Chassis Layout Starsight Newosd FRO. SurrConstruction of Chassis Major Features Section II TUNER, IF/MTS/S. PRO Module Circuit BlockOutline RF AGCAudio Multiplex Demodulation Circuit A.PRO block diagram A.PRO Section Audio ProcessorConfiguration of the audio circuit and signal flow are given POP Tuner Terminal No NameOperation of Channel Selection Circuit Microcomputer SDA SCLMicrocomputer Terminal Function Microcomputer Terminal Name and Operation Logic Terminal Name Function In/Out Logic RemarksSDA On Screen FunctionEEPROMQA02 System Block Diagram Local KEY Detection Method Local key assignment FunctionTo TV set Remote Control Code AssignmentCode Function Custom codes are 40-BFH TV set for North U.S.A Code Function Optional Setting for Each Model OPT0 OPT1 Models HEXService Adjustment Entering to Service ModeTest Signal Selection Executing Self Diagnosis Function Failure Diagnosis ProcedureContents to be Confirmed by Customer Understanding Self Diagnosis Indication Self CheckClearing method of self diagnosis result YES Troubleshooting ChartTV does Not Turned on No Acception of KEY-IN No Picture Snow NoiseMemory Circuit Check No Indication On ScreenSection IV DVD Switch Circuit DVD Switch Block Diagram Outline Configuration Section V WAC Circuit OutlineCircuit Operation OperationWide aspect conversion unit block diagram PB6348 Pin Function Pin function of TC9097F QFP 80 pinNames and functions of TC9097F Name FunctionVFL2 Block Diagram TC9097F system block diagramWide Aspect Conversion Circuit Failure Analysis Procedures E2PROM OK?Adjustment Method Raster Horizontal OneScreen multi-search process Section VI Dual Circuit OutlinePrinciples of Operation System Component Diagram of Dual Unit Video/Color/Deflection Process Section OSD Sub Screen Process Section Sub screen process sectionMain/Sub Screen Superimposing Section Main/Sub screen superimposing sectionMain IC Terminal FUNCTION, Description and Block Diagram DiagramQY01 MPC1832GTQY01 mPC1832GT pin layout QY03 TC9092AF internal block diagram QY03 TC9092AF pin layout QY03 TC9092AF pin list No Pin name Pin function CKWMRD1 QY10/QY11 M518221-30ZS internal block diagram Circuit Description Section VII 3-DIMENSION Y/C Separator Circuit OutlineConfiguration Circuit Description Terminal description PZ01 Section Viii Vertical Output Circuit Outline Theory of OperationOutput Circuit Actual CircuitSawtooth Waveform Generation Circuit OperationOutput Output stage power supply voltage Linearity Characteristic Correction Protection Circuit for V Deflection StopCharacter Correction Up-and Down-ward Extension Correction Up-and Down-ward Linearity Balance+35V Over Current Protection Circuit Theory of OperationUZ22BSD UZ11BSBRaster Position Switching Circuit KetsuSignal Section IX Horizontal Deflection Circuit OutlineHorizontal Drive Circuit Basic Operation of Horizontal DriveOn period OFF period Signal DEF/POWER PCB Horizontal Output CircuitOperation of Basic Circuit FBTDescription of the basic circuit T1~t2 T2~t3T3~t4 T4~t6Curve Correction S Capacitor Amplitude CorrectionLinearity Correction LIN Left-right Asymmetrical Correction LIN coil Linearity coilWhite Peak Bending Correction Circuit OutlineOperation Theory EHTBlanking Low Voltage Protection Gate ProtectorHigh Voltage Generation Circuit AFCABL High Voltage DPC Circuit RegulatorHigh Voltage 1. +210V2. +35V Anode High Voltage CircuitCR-BLOCK ED’ ActualFBT CR-BLOCK E H RAY Protection Circuit 23 X-RAY protection circuitOver Current Protection Circuit Functions and Features Block DiagramDiode Modulator Circuit OUTActual Circuit First Half Scanning Period Basic Operation and Current PathLater Half Scanning Period P.T Later Half of Flyback PeriodFirst Half of Scanning Period Section XI Digital Convergence Circuit Outline Reset MemoryProm PLLPicture Adjustment Service Mode Entering/Exiting ModeSfull Initial screenFirst screen Second screen Key function of remote control unit ENTNormal/Full Operation procedureEach Screen Adjustment Method Theater Wide1 Theater Wide 269.5 Case Study When CRT is ReplacedWhen Convergence Unit is Replaced Adjusting Procedure in Replacing Convergence Unit/Main Def TroubleshootingAdjusting Procedure in Replacing CRT Convergence Output Circuit Convergence Block Diagram Convergence Troubleshooting Chart Main Unit
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