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Sharp SF-1020, SF-1120 service manual Heater lamp control circuit, General

Models: SF-1120 SF-1020

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Page 131

(6) Heater lamp control circuit

				+5V1
R67	R71
1KJ	47KJ
11
13	R7 5
10	R7 5	Q7			C6
10		Q7			C6
IC20D	75J	2SC945			R80	OP-LATCH
NJM2901	C7					OP-LATCH
R6 8			R84		24KJ	CPU 17PIN
					24KJ
5.6KJ				D41	0.22µ F
5.6KJ	0.22µ F		10KJ	D41	0.22µ F
	0.22µ F		10KJ

Vref

R91

R87

R89

8.2KJ

1MJ

4.7KF

8

14

D3 8

9

D6

D7

IC20C

C55

MA700

D16

NJM2901

R93

R9 2

DSM101

680J

22000PF

47KF

8 ~ 20

PR

Q 5

2SA573

R54

R53

+24V

IC9

5.6KJ

47KJ

16

1

O1

I1

15

2

14

O2

I2

3

Heat roller

O3

I3

R32

PR

13

O4

I4

4

2.7KJ

CPU

12

O5

I5

5

HL

AN1

11

O6

I6

6

10

O7

I7

7

9

8

SK

G

ULN2004

R35

PR

+5V2

L2

270J

1/4W

10K

Q3

2.2K

GATE

T1

DTA123Y5

T2

PR

GND

AC PWB

AC PWB

200V AREA

MLSW

ML

AC

MLSW	ML

ML : 1KW

N1

1General

The heater lamp control circuit detects the heat roller surface temperature with the thermistor, converts it into a voltage, and out- puts it to the CPu analog input pin.

The CPU converts analog signals into digital signals, compares them with the value set by test commands to turn on/off the heater lamp, maintaining the heat roller surface temperature at a constant level.

The higher the heat roller surface temperature is, the greater the thermistor resistance is, and vice versa.

Therefore, the lower the heat roller surface temperature is, the higher the thermistor pin voltage is. The thermistor pin voltage is inputted to the analog port of CPU, which controls ON/OFF of the heater lamp according to the input voltage level.

[High temperature protect circuit when the CPU is hung up (out of control)]

1)The IC20 8 pin voltage (reference voltage) is divided by R91 and R93. The thermistor pin voltage is inputted to the IC20 9 pin. When the voltage at 9 pin becomes lower than the voltage at 8 pin (the heat roller surface temperature about 240V), the IC20 14 pin is driven to LOW, pulling down the PR signal to the GND level, turning off the AC power of the heater lamp.

2)Since the OP-latch signal is fixed to HIGH or LOW, the collector of Q7 is open. The voltage at IC20 10 pin is higher than the voltage at IC20 11 pin (reference voltage), and IC20 13 pin is driven to LOW.

With the above operations, IC9 13 pin is opened to turn off Q5, turning off the power relay. As a result, the AC power of the heater and the copy lamp is turned off.

*The double protection with 1) and 2) is provided.

12 – 12

Image 131

Sharp SF-1020, SF-1120 service manual Heater lamp control circuit, General

Contents

SF-1020 SF-1120 Contents Lower heat roller replacement Electrical Section Product Outline Product featuresSystem configuration options ADU Product SpecificationsBasic specifications SF-CM16 Description of each sectionSF-CM15 SF-LS12 Supply partsBrazil/Asia except Hong Kong Middle East/AfricaOptional specifications One-step paper feed unit SF-CM16 Bin staple sorter 10-bin SS Model name SF-S54Staple section Two-step paper feed unit Model name SF-CM15External view and internal structure Product ViewsSF-1020 Operation panelSF-1120 Motors Clutches and solenoidsPWB Explained with the SF-1120 and the SF-CM15 POD TCSIlsw MSWRollers, mirrors, etc Unpacking Unpacking and InstallationInstallation Installing conditionsSpace around the machine Installation basePower source Grounding wire connectionNo /3 mirror unit lock release Charger cleaningMain charger unit electrode cleaning Optical system lock releaseDeveloping unit setting Developing unit settingDeveloping unit level adjustment Accessory installationToner density sensor level adjustment Copy tray installationPage Label attachment Center shift adjustmentLabel attachment Parts packed together Optional two-step paper feed unit SF-CM15 installationRemoving the rear cover to the main copier units lower tray ING and InstallationOptional one-step paper feed unit SF-CM16 Included partsPlugging in the relay harness Placing the main copier unit over the paper feed unitRemoving the lower tray from the main copier unit Attaching the main copier unit and paper feed unitRemove the tray Set the modeTray paper size selection Described with the SF-1020 Centering the paperSet paper, and change the paper size display Attach the trayBasic operations Descriptions of Each SectionPaper feed section General descriptionsBasic composition Developing sectionGeneral description Optical sectionBasic operations Lens home position sensor Lhps Original table Copy lampMirror Lens fixed focus lensMirror base drive wire Lens drive wireTemperature fuse Exposure adjustment plateEX1 EX5 Original size sensingCLV CPU Optical system dirt correctionPhotoconductor Copy processThis model basic process and structure Process diagram CTL CGL Details of image forming processMain Charging ExposureCGL CTL DevelopmentCTL TransferSeparation Discharging CleaningSummary Transition of photoconductor surface potentialPhotoconductor drum sensitivity correction Process control functionBasic structure Process controlProcess control timing Drum markingBasic composition and functions Fusing paper exit sectionGeneral Basic operation High voltage sectionADU unit SF-1120 only Basic compositionDetails of operation Paper feed roller assy removal Disassembly and AssemblyPaper feed unit Paper feed roller, take-up roller PS front roller assySeparation roller Transport unit Transport belt Upper heat roller assy removal Fusing sectionFusing unit removal Heater lamp replacementLower separation pawl replacement Upper separation pawl replacementLower heat roller replacement Thermistor/thermostat removal Copy lamp replacementMirror base wire replacement and adjustment Optical systemNo /3 mirror unit mirror base B removal Mirror base wire removalMirror base wire fixing No /3 mirror unit mirror base B assemblyMirror base wire stretching Page No /5 mirror removal Copy lamp unit installation Mirror base a positioningNo /5 mirror unit mirror base C replacement No /5 mirror unit assembly Lens wire removal Lens wire replacementProcedures Lens removal Lens unit replacementLens unit installation Main charger MC unit Cleaning/replacement and noteHigh voltage section Process unit ~0.5 Cleaning/replacement and precautionsProcess section Transfer/separation charger TC/SC unitPage Drum Replace every 50K copies Blank lamp unit Clean every 50K copiesDischarge lamp unit Clean every 50K copies Toner reception seal Replace every 50K copies Cleaner blade Replace every 50K copiesDV side seals F/R replacement Replace every 120K copies Drum separation pawl Replace every 50K copiesRing attachment DB blade replacement Replace every 120K copiesDeveloping unit color identification Cooling fan motor replacementOperation panel/intermediate cabinet Frame major partsCooling fan motor Power unitTray size detecting PWB Main PWB unit AC power PWBTake-up roller/paper feed roller Multi paper feed unit SF-MF15 optionPaper feed roller ADUReverse roller Paper feed unit SF-CM15, SF-CM16, option Adjustment procedure AdjustmentsDeveloping doctor clearance adjustment Developing magnet roller main pole position adjustmentAdjustment items YES 51 50 Adjustment of each sectionLens reference position adjustment No /5 mirror reference position adjustment110 Vertical copy magnification ratio adjustmentResolution adjustment Focus adjustment No.4/5 mirror adjustment screw Adjustment procedure Horizontal copy magnification ratio adjustmentComparison table of lens values and simulation input values Horizontal skew adjustment Vertical skew adjustmentMirror base rail handle Loosen Exposure balance adjustment Center shift adjustmentCopy lead edge adjustment End of scale image Original detecting section Original detecting arm unit adjustmentA4R LTR Original detecting level adjustment3 4 5 6 Purpose Operating procedureSimulations operating procedure SimulationList of simulations Cassette size switch table Simulation 26-6 Destination settingDetails of simulations Full power on Psps WLT LTR INV A4R B5RADF counter display ← Initial value OFF SEC Secl Seeg SUK SCAPPD4 PPD1PPD2 PPD3PD3 PD0PD1 PD2Developer counter clear Display range 8 ∼ No trouble 31 ∼ 35 --- Trouble The sub code is displayed Copying without grid bias correction AE + PE ME + PEPaper transport direction magnification ratio adjustment ADU alignment plate home position adjustment SF-2120 only 30 sec. This function can be cleared User simulationLED User simulationUser simulation code table Clearing the self diag display Self DiagnosticsSummary/purpose OperationSF-1120 only LOW HighRemedies GeneralMake a copy and adjust Set value recording sheet Memory simulation list Maintenance cycle and maintenance items MaintenanceElectrical Section System block diagramRPL on PSW on RPL OFF System operation when the power is turned onJAM Main circuit Block diagramPin arrangement FeaturesCPU IC6 SC3041K12F RAM Internal block diagramDMA Dmac ROMCPU SC3041K12F IC1 pin signal NMI RES ResetMCS CLK OUTVDD O IC8 CXD1095QOden O CXD1095Q IC8 pin signal PC2 CPEC2 OUT CLR ResetOden Reset PC1 CPFC1 OUTSEL a SEL B SEL C Detector circuit of sensor signalStart/stop control circuit SEL C SEL B SEL aHeater lamp control circuit Load Driver circuit Solenoid, electromagnetic clutchStepping motor drive circuit OperationCW/CCW Reset IC IC13AE Auto Exposure sensor circuit Toner supply motor drive circuitKI2 CPU Operation panelKI0 KI1 Hound AC Circuit EnergyStar circuit descriptionADU circuit description ADU circuit block diagramROM RAM ADU CPU IC1Stby TXDDSR RESADU motor DDM drive circuit Stepping motor PAM1, PAM2 drive circuitGND