Toshiba TW40F80 manual Actual, Fbt Cr-Block E H, Ed’

Page 78

6-1-3. Actual

Fig. 9-22 shows the actual circuit used in the unit.

A resonant capacitor C0 is also split into two capacitors C443 and C444 in this circuit. The high voltage regulator cirucits is structured by splitting the C443 to two capacitors of C443 and C448.

Here, assume a high voltage increases and the detection volt- age ED' obtained by dividing the high voltage also increases in proportional to the high voltage. This makes the voltage ED increase at pin 7. (The voltage is impedance transformed by a voltage follower circuit consisting of op amplifier Q483 at pin 7.)

The voltage ED and a 9V reference voltage developed by a 3-terminal regulator Q420 are compared. When the ED in- creases, the voltage at pin 2 of Q483 differential amplifier also increases, and the base current IB of the high voltage transistor Q480 increases.

As a result, Q480 collector current increases and Q480 col- lector voltage (at the point B ) decreases. Then, a peak value of VCP2 across C418 is clamped by the diode D443 at the collector voltage lowered, and the collector voltage VCP of Q404 (H output transistor) obtained as a sum of the voltage VCP1 across C443 and VCP2 across L418 decreases. Then, the high voltage also decreases.

When the high voltage lowers, the corrective operation is carried out in reverse order.

*Resustors R451, R452, R453 and R455 are used to cor- rect undersirable influence (H amplitude increase at mini- mum IH) by the H amplidude regulator.

FBT

 

CR-BLOCK EH

 

 

 

 

 

Horizontal

Q404

C443

 

L462

 

 

 

 

 

 

 

output

 

C440

 

 

 

 

 

 

 

 

 

L463

 

 

 

 

 

 

 

 

 

 

 

-27V

 

 

 

 

 

 

 

 

 

L464

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C444

CS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R460

125V

 

 

 

 

 

 

 

 

R466

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C467

 

 

 

 

 

R455

 

 

ED’

D461

 

 

 

 

R461/R469

Q462

 

 

 

 

 

 

 

 

 

 

 

 

L461

 

 

 

R435

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R463

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Q460

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Q483

 

C482

 

 

 

C464

 

 

 

 

 

 

 

 

 

 

 

 

 

R454

 

 

 

 

 

 

 

 

 

 

 

 

ED

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8

6

 

 

 

D443

 

R451

R452

R453

 

 

7

 

 

 

B

 

 

 

 

 

 

D444

 

 

 

 

 

 

R489

 

 

 

C418

 

 

 

 

 

 

 

 

 

 

 

 

 

C419

 

Q480

R434

 

4

R450

 

 

 

 

 

 

 

 

2

 

 

 

 

 

 

 

 

 

3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R488

R490

 

 

 

 

 

 

 

R431

R492

 

 

 

 

 

 

 

 

 

 

 

 

 

Q420

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C483

R494

R439

9V-1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R487

 

Fig. 9-22 Actual high voltage regulator circuit

78

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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 CircuitOutline Merits of BUS System Section FeatureImproved Serviceability Reduction of Parts CountSpecifications Chassis ModelFront View Video 3 InputsRear View IN-VIDEORemote Control View 100Chassis Layout Starsight Newosd FRO. SurrConstruction of Chassis Outline Major FeaturesSection II TUNER, IF/MTS/S. PRO Module Circuit Block 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 RemarksOn Screen Function EEPROMQA02SDA System Block Diagram Local KEY Detection Method Local key assignment FunctionRemote Control Code Assignment Code FunctionTo TV set Custom codes are 40-BFH TV set for North U.S.A Code Function Optional Setting for Each Model OPT0 OPT1 Models HEXEntering to Service Mode Test Signal SelectionService Adjustment Failure Diagnosis Procedure Contents to be Confirmed by CustomerExecuting Self Diagnosis Function Understanding Self Diagnosis Indication Self CheckClearing method of self diagnosis result Troubleshooting Chart TV does Not Turned onYES No Acception of KEY-IN No Picture Snow NoiseMemory Circuit Check No Indication On ScreenSection IV DVD Switch Circuit DVD Switch Block Diagram Outline Circuit Operation ConfigurationSection V WAC Circuit Outline 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 OneSection VI Dual Circuit Outline Principles of OperationScreen multi-search process 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 sectionQY01 Main IC Terminal FUNCTION, Description and Block DiagramDiagram 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 Section VII 3-DIMENSION Y/C Separator Circuit Outline Configuration Circuit DescriptionCircuit Description Terminal description PZ01 Section Viii Vertical Output Circuit Outline Theory of OperationSawtooth Waveform Generation Output CircuitActual Circuit Circuit OperationOutput Output stage power supply voltage Character Correction Up-and Down-ward Extension Correction Linearity Characteristic CorrectionProtection Circuit for V Deflection Stop Up-and Down-ward Linearity BalanceUZ22BSD +35V Over Current Protection CircuitTheory of Operation UZ11BSBRaster Position Switching Circuit KetsuHorizontal Drive Circuit SignalSection IX Horizontal Deflection Circuit Outline Basic Operation of Horizontal DriveOn period OFF period Operation of Basic Circuit Signal DEF/POWER PCBHorizontal Output Circuit FBTT3~t4 Description of the basic circuit T1~t2T2~t3 T4~t6Amplitude Correction Linearity Correction LINCurve Correction S Capacitor Left-right Asymmetrical Correction LIN coil Linearity coilOperation Theory White Peak Bending Correction CircuitOutline EHTBlanking Low Voltage Protection Gate ProtectorABL High Voltage Generation CircuitAFC High Voltage DPC Circuit Regulator1. +210V 2. +35VHigh Voltage High Voltage Circuit CR-BLOCKAnode Actual FBT CR-BLOCK E HED’ RAY Protection Circuit 23 X-RAY protection circuitOver Current Protection Circuit Functions and Features Block DiagramDiode Modulator Circuit OUTActual Circuit Basic Operation and Current Path Later Half Scanning PeriodFirst Half Scanning Period Later Half of Flyback Period First Half of Scanning PeriodP.T Section XI Digital Convergence Circuit Outline Prom ResetMemory PLLPicture Adjustment Service Mode Entering/Exiting ModeInitial screen First screen Second screenSfull Key function of remote control unit ENTOperation procedure Each Screen Adjustment MethodNormal/Full Theater Wide1 Theater Wide 269.5 When CRT is Replaced When Convergence Unit is ReplacedCase Study Troubleshooting Adjusting Procedure in Replacing CRTAdjusting Procedure in Replacing Convergence Unit/Main Def Convergence Output Circuit Convergence Block Diagram Convergence Troubleshooting Chart Main Unit
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