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Toshiba TW40F80 manual High Voltage Generation Circuit, Theory of Operation

Models: TW40F80

1 101

Page 75

5. HIGH VOLTAGE GENERATION CIRCUIT

The high voltage generation circuit develops an anode volt- age for the picture tube, focus, screen, CRT heater, video output (210V) and so on by stepping up the pulse voltage developed for flyback period of the horizontal output cir- cuit with the FBT, and supplies the power to various cir- cuit.

5-1. Theory of Operation

Auxiliary

winding

Primary winding

AFC			10
blanking			10
blanking
Heater			9
+12V-1			R448
		C303	R448
			4
+35V			C447
		D302	D408
C310		D302	7
C310			7
			R327
			6
	C460	D460	R469
		D460	R469
-27.5V			5
+210V		D406	R443
+210V			3
			3
+125V	C446
+125V			2
R444
	C448		1
			1

CRT anode

Focus pack

Q404	C440	C443	C444	ABL
	C440	C443	C444
T401
C463				H deflection coil	1H
	C418		C467	L462/L463/L464	(15.625kHz)
				L462/L463/L464

			L441	R441
			L441
				C423
HIGH VOLTAGE		DPC CIRCUIT
REGULATOR
CIRCUIT

1040V(p-p)

Fig. 9-15

Page 75

Image 75

Toshiba TW40F80 manual High Voltage Generation Circuit, Theory of Operation

Contents

TW40F80 PROJECTION TELEVISIONTECHNICAL TRAINING MANUAL N5SS CHASSIS SECTION II TUNER, IF/MTS/S. PRO MODULE Contents9. REMOTE CONTROL CODE ASSIGNMENT SECTION IV DVD SWITCH CIRCUITSECTION VII 3-DIMENSION Y/C SEPARATOR CIRCUIT 5. TERMINAL FUNCTION, DESCRIPTION AND BLOCK DIAGRAM OF4. WIDE ASPECT CONVERSION CIRCUIT FAILURE ANALYSIS 3. SYSTEM COMPONENT DIAGRAM OF DUAL UNITSECTION XI DIGITAL CONVERGENCE CIRCUIT SECTION X DEFLECTION DISTORTION CORRECTION CIRCUIT7. CONVERGENCE TROUBLESHOOTING CHART 1. DEFLECTION DISTORTION CORRECTION IC TA8859CP2-2. Reduction of Parts Count SECTION 1. FEATUREOUTLINE 2. MERITS OF BUS SYSTEM 2-1. Improved ServiceabilityTW56F80 TW40F80 3. SPECIFICATIONSC-Chassis ModelNote No Owners manual page 4. FRONT VIEWIN-VIDEO 5. REAR VIEWTOSHIBA 6. REMOTE CONTROL VIEW6 DUAL 7. CHASSIS LAYOUT8. CONSTRUCTION OF CHASSIS A517BRT TBS 1-1. Outline SECTION II TUNER, IF/MTS/S. PRO MODULE 1. CIRCUIT BLOCK1-2. Major Features Fig. 2-1 Block diagramTable 2-1 Matrix for broadcasting conditions and reception mode Fig. 2-2 Block diagram of MVUS34SSwitching 1-3. Audio Multiplex Demodulation Circuit1-4. A.PRO Section Audio Processor Fig. 2-3 A.PRO block diagramFRONT INPUT Configuration of the audio circuit and signal flow are given in FigMOTHER VIDEOName 2. POP TUNER2-1. Outline Terminal NoSECTION III CHANNEL SELECTION CIRCUIT 1. OUTLINE OF CHANNEL SELECTION CIRCUIT SYSTEM2. OPERATION OF CHANNEL SELECTION CIRCUIT 3. MICROCOMPUTER 4. MICROCOMPUTER TERMINAL FUNCTION In/Out MICROCOMPUTER TERMINAL NAME AND OPERATION LOGICTerminal Name Function6. ON SCREEN FUNCTION 5. EEPROM QA027. SYSTEM BLOCK DIAGRAM Function 8. LOCAL KEY DETECTION METHODFig. 3-6 Local key assignment Table 3-1 Local key assignment Functionto TV set 9. REMOTE CONTROL CODE ASSIGNMENTCode FunctionCustom codes are 40-BFH TV set for North U.S.A Custom codes are 40-BFH TV set for North U.S.ACode FunctionMODELS 9-1. Optional Setting for Each ModelOPT0 OPT110. ENTERING TO SERVICE MODE 11. TEST SIGNAL SELECTION12. SERVICE ADJUSTMENT Contents of self diagnosis 13. FAILURE DIAGNOSIS PROCEDURE13-1. Contents to be Confirmed by Customer 13-3-1. ProcedureSELF CHECK Contents13-4. Understanding Self Diagnosis Indication Example of screen display13-4-2. Method utilizing inner signal 13-4-1. Clearing method of self diagnosis resultVIDEO INPUT 1 terminal should be open 14-1. TV does Not Turned ON 14. TROUBLESHOOTING CHARTNo picture NG Voltage at pins of +5V, and OK Key on TV Voltage change at pins 17, 18 of QA01 5V to OK Replace QA01When remote unit key is pressed OK Replace QA01 NG Check key-in circuit NG Check tuner power circuit14-5. No Indication On Screen 14-4. Memory Circuit CheckSECTION IV DVD SWITCH CIRCUIT 1. DVD SWITCH BLOCK DIAGRAM QV01 TA1218N 2. OUTLINEOpen at Cb input Cb to DVD SW unit Cb input RV28 100k RV27 10k2-2-1. Signal Flow SECTION V WAC CIRCUIT 1. OUTLINE2. CIRCUIT OPERATION 2-1. ConfigurationFig. 5-1 Wide aspect conversion unit block diagram PB6348 Pin Function Fig. 5-2 Pin function of TC9097F QFP 80 pinVDD5VCO2 Table 5-1 Names and functions of TC9097F NameFunction Function NameFunction 3. BLOCK DIAGRAMFig. 5-3 TC9097F system block diagram Name4. WIDE ASPECT CONVERSION CIRCUIT FAILURE ANALYSIS PROCEDURES 4-2. Raster Horizontal One 4-2-1. Adjustment Method9-screen multi-search process SECTION VI DUAL CIRCUIT1. OUTLINE 2. PRINCIPLES OF OPERATION3. SYSTEM COMPONENT DIAGRAM OF DUAL UNIT 4-1. Video/Color/Deflection Process Section 4. CIRCUIT OPERATIONSignalreception Fig. 6-3 Sub screen process section 4-2. Sub Screen Process SectionFig. 6-4 Main/Sub screen superimposing section 4-3. Main/Sub Screen Superimposing SectionQY01 MAIN IC5. TERMINAL FUNCTION, DESCRIPTION AND BLOCK DIAGRAM OF diagramPower supply video Fig. 6-6 QY01 mPC1832GT pin layoutBlanking pulse output MEMORY Fig. 6-7 QY03 TC9092AF internal block diagramMULTIPLEX PROGRAMDATAADVREFY Fig. 6-8 QY03 TC9092AF pin layoutTable 6-1 QY03 TC9092AF pin list No Pin namePin function Table 6-2 QY03 TC9092AF pin list No Pin namePin function Terminal name Fig. 6-9 QY10/QY11 M518221-30ZS internal block diagramPower supply +5V Fig. 6-10 QY10/QY11 M518221-30ZS pin layout1. OUTLINE SECTION VII 3-DIMENSION Y/C SEPARATOR CIRCUIT2. CIRCUIT DESCRIPTION 2-1. ConfigurationVoltage Fig. 7-1 3-dimension Y/C separator unit block diagramSignal name Terminal description PZ011-1. Theory of Operation SECTION VIII VERTICAL OUTPUT CIRCUIT 1. OUTLINE2-2-1. Circuit Operation 2. V OUTPUT CIRCUIT2-1. Actual Circuit 2-2. Sawtooth Waveform Generation2-3-1. Circuit Operation 2-3. V OutputFig. 8-7 Output stage power supply voltage 2-4-2. Up-and Down-ward Linearity Balance 3. PROTECTION CIRCUIT FOR V DEFLECTION STOP2-4. V Linearity Characteristic Correction 2-4-1. S-character Correction Up-and Down-ward Extension Correction3-1-1. Theory of Operation 3-1. +35V Over Current Protection Circuit4. RASTER POSITION SWITCHING CIRCUIT 4-1. Outline4-2. Operation Fig. 9-1 H drive circuit block diagram SECTION IX HORIZONTAL DEFLECTION CIRCUIT2. HORIZONTAL DRIVE CIRCUIT 3. BASIC OPERATION OF HORIZONTAL DRIVEcurrent + ibOn period OFF period4. HORIZONTAL OUTPUT CIRCUIT 4-1. Theory of Operation4-1-1. Operation of Basic Circuit 4. t3~t4 Description of the basic circuit 1. t1~t22. t2 3. t2~t3Amplitude Correction 4-1-2. Linearity Correction LIN1 S-curve Correction S Capacitor Fig. 9-9 Linearity coil 2 Left-right Asymmetrical Correction LIN coilFig. 9-11 White peak bending correction circuit 4-2. White Peak Bending Correction Circuit4-2-1. Outline 4-2-2. Operation Theory4-3-3. Circuit Operation 4-3. H Blanking4-3-1. Outline 4-3-2. Theory of Operation4-4. 200V Low Voltage Protection 4-4-1. Outline4-4-2. Theory of Operation 5-1. Theory of Operation 5. HIGH VOLTAGE GENERATION CIRCUIT5-1-4. High Voltage 5-1-1. +210V5-1-2. +35V 5-1-3Fig. 9-19 Basic circuit for high voltage regulator 6. HIGH VOLTAGE CIRCUIT6-1. High Voltage Regulator 6-1-1. OutlineFig. 9-22 Actual high voltage regulator circuit 6-1-3. ActualFig. 9-23 X-RAY protection circuit 7. X-RAY PROTECTION CIRCUIT7-1. Outline 7-2. OperationFig. 9-24 Over current protection circuit 8. OVER CURRENT PROTECTION CIRCUIT8-1. Outline 8-2. OperationBlock Diagram SECTION X DEFLECTION DISTORTION CORRECTION CIRCUIT SIDE DPC CIRCUIT1. DEFLECTION DISTORTION CORRECTION IC TA8859CP 1-2. Functions and Features2. DIODE MODULATOR CIRCUIT 3. ACTUAL CIRCUIT 3-1. Basic Operation and Current Path 3-1-1. Later Half Scanning Period3-1-2. First Half Scanning Period 3-1-4. First Half of Scanning Period 3-1-3. Later Half of Flyback Period2. CIRCUIT DESCRIPTION SECTION XI DIGITAL CONVERGENCE CIRCUIT2-1. Configuration 1. OUTLINE∗∗∗812bit8 Fig. 11-1 Block diagram3. PICTURE ADJUSTMENT 3-2. Service Mode 3-2-1. Outline3-2-2. Entering/Exiting Mode 3-2-3. Initial screen 1 First screen2 Second screen TOSHIBA 3-2-4. Key function of remote control unit3-2-5. Operation procedure 3-3. Each Screen Adjustment Method3-3-1. Normal/Full 3-3-2. Theater Wide1 3-3-3. Theater Wide 3-3-4. Theater Wide 4. CASE STUDY 4-1. When CRT is Replaced4-2. When Convergence Unit is Replaced 5. TROUBLESHOOTING 5-1. Adjusting Procedure in Replacing CRT5-2. Adjusting Procedure in Replacing Convergence Unit/Main Def 6-1. Outline 6. CONVERGENCE OUTPUT CIRCUIT6-2-1. Signal flow 4 To adjust from outside of digital convergence6-3. Convergence Block Diagram Vertical 7. CONVERGENCE TROUBLESHOOTING CHARTDV DH WIDEF BP VOLTAGEREG