Sharp AR-CF2 service manual Inrush Current Limiting Circuit, Operator Panel Drive Circuit

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(7)Inrush Current Limiting Circuit

JAM cover open/closed

This circuit limits an inrush current flowing into the regeneration capac- itor included in the motor drive system to a certain value or less. The circuit consists of the PTC thermistor (PTH2) that limits a current and the FET (Q11) that allows a steady current flowing.

When the JAM cover open/closed detection switch is closed, the cath- ode voltage of ZD1 starts rising to the zener voltage according to the time constant of R55 and C46. During the rise of the cathode voltage, Q11 is off because no base current to Q10 keeps Q10 off, and then a current flows to PTH2 to charge the regeneration capacitor.

(8) Operator Panel Drive Circuit

Operator Panel

This circuit includes the input circuits of the switches on the operator panel and the drive circuits of the LEDs.

The circuits connected to CN15-Pin1, 2, 3 are the input circuits of the switches on the operator panel. The input signal from the switch goes "L" when the switch is on, "H" when off.

The circuits connected to CN15-Pin4,6-11 are the drive circuits of the LEDs on the operator panel. The LED lights when the signal is "H", does not light when "L".

After the regeneration capacitor is fully charged, and the cathode volt- age of ZD1 reaches over the zener voltage according to the time con- stant of R55 and C46, Q11 is turned on because the base current from ZD1 to Q10 turns Q10 on. And then the current flows to Q11 instead of PTH2 to release the current limitation. The circuit consisting of PTH1 and D3 is intended to eliminate the electric charge accumulated in C46 immediately to limit an inrush current generated by momentary open- ing and shutting of the cover.

AR-CF2 ELECTRICAL SECTION 9 - 8

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Contents Sharp Corporation Specifications Product OutlineExternal components Sensors and switchesExternal Views and Internal Structures AR-CF2 External Views and Internal Structures 3Motors, solenoid, and clutch Function outline Operational DescriptionStructure Operational descriptionNormal paper feed operation of inserter online/ offline Reverse paper feeding operation of inserter Entering reverse sectionHow to set stapling mode Offline mode settingHow to set punching mode Exiting from reverse sectionLED LED1 LED2 LED3 LED4 Start LED Mode LEDLED indication on operator panel Alarm detection Paper jam/error detectionError detection List of Paper jamsAR-CF2 Adjustments 5 AdjustmentsPaper width detection level setting adjustment LEDPaper Feed Separation Unit Disassembly and AssemblyAR-CF2 Disassembly and Assembly 6 Pickup Roller & Paper Feed RollerHorizontal Pass Roller 2 and Timing Roller Paper Feed UnitHorizontal Pass Roller 1 and Registration Roller Paper Guide Reverse Roller Other Parts Sensors Reverse flapper solenoid adjustmentDrive Unit BeltsAR-CF2 Maintenance 7 MaintenanceMaintenance list PCB TroubleshootingAR-CF2 Troubleshooting 8 Tray alarm is displayed on the system display AR-CF2 Electrical Actual Wiring ChartElectrical Section Outline Block DiagramCircuit Description DC+5VSensor Input Circuits Circuit DetailCommunication Circuit Paper Exit Sensor Hisen Paper Width Detection Potentiometer TVR Motor Drive Circuits Paper Feed Motor Drive Circuit KmotReset Circuit Eeprom Circuit Inrush Current Limiting Circuit Operator Panel Drive CircuitOperator Panel Circuit Memo Memo LEAD-FREE Solder ExampleVaroitus Trademark acknowledgements
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