Stepping motor operation circuit | LG Electronics GR-P257/L257

EXPLATION FOR MICOM CIRCUIT

1-10. Stepping motor operation circuit

(1)GR-P227/L227/P257/L257

The motor is driven by magnetism formed in the areas of the coils and the stator. Rotation begins when a HIGH signal is applied to MICOM Pin 33 of IC10 (TA7774F). This causes an output of HIGH and LOW signals on MICOM pins 34 and 35.

Explanation) The stepping motor is driven by sending signals of 3.33 mSEC via MICOM pins 33, 34, and 35, as shown in the chart below. These signals are output via terminals 10, 11, 14, and 15 via input terminals 3, 6, and 8 of IC10 (TA7774F), the motor drive chip. The output signals allow the coils wound on each phase of the stator to form a magnetic field, which causes rotation. Input to the terminals INA and INB of IC10 as shown in the chart below drives the motor.

CCW (Reverse rotation)				(Positive rotation) CW

INA

INB

A

B

A

B

- 33 -

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LG Electronics GR-P257/L257, GR-P227/L227 service manual Stepping motor operation circuit

Contents

Refrigerator Contents Page Front View Specifications Ref No. GR-L227 Ref No. GR-P257 Ref No. GR-L257 Freezer Refrigerator compartment compartment Parts Identification Ref No. GR-P227/GR-P257EXTERNAL Filter Parts Identification Parts Identification How to Adjust Door Height of Refrigerator HOW to Install Refrigerator Class Shape and Spec Nomenclature How to Install Water PipeBefore Installation General Type Connection of Pipe Connector a and BSingle Lever Type Faucet general Two Hands Type Faucet Outternal Filter Filter Fixation When customer uses bottled waterFilter Cleaning Replacement of water filter After installing water filter Confirm the amount of water supplied to the icemaker How to Control the Amount of Water Supplied to Icemaker Monitor Panel Door Alarm Buzzer Mute ModeDisplay Power saving Mode Micom Function Description of Function Exhibition Mode Filter condition display function Outside temperature display functionLCD Back Light Control Lock function display button lock Express Freezer When ice maker does not operate smoothlyDispenser use selection Automatic ice maker Control of variable type of freezing room fan Super freezingMiracle Zone function Or home bar Door opening alarmControl of M/C room fan motor Doors of freezing Sequential operation of built-in product Failure Diagnosis Function Test Function Mode Operation Contents Remarks Function of dispenser and water dispenser built-in Test Mode 1 Status LCD Test Mode 2 Status LCD GR-P227/L227 Power circuitExplation for Micom Circuit Explanation for PWB circuit GR-P227/L227/P257/L257 Reset circuitOscillation circuit Load Driving Circuit Load/dispenser operation, door opening circuit Dispenser operation circuit Lever Switch sensing circuit Measuring part Door opening sensing circuit Short Open Temperature sensing circuit Separation Connection Status Application Standard Switch entry circuitOption designation circuit model separation function Stepping motor operation circuit Fan motor driving circuit freezer, mechanical area +5 C +9F 33 k Ω 56 k Ω JCR1 Main PCB Sensor resistance characteristics table Miracle Zone Stepping Motor / Display Operation Principle Water supply amount Table Harvest ModeIcemaking Mode Fill/Park Position Defect diagnosis function Stage Items Indicator Remarks Circuit Trouble Diagnosis Trouble Shooting Not performed Evaporator by heating as Refrigeration Refrigeration Residual Refrigeration No cooling air circulation Is weak Fan does not work Recess Sounds Compressor compartment operating sounds Bad soldering Bad rivet contact Short Structure Door foam Appearance Sag Problems Causes Checks Measures FaultsPower Problems Causes Checks Measures Remarks Temperature Cooling Disconnected from the motor Refer to fan motor disassembly Measures Remarks Problems CausesDefrosting failure Remove the parts and replace it Icing Discharging port of cooling air Sound Click Contraction of evaporator Sources Sound Burping It happens when refrigerant expands Odor Micom Problems Symptom Causes Checks Measures Remarks Driving circuits Motor damper Replace door switch Trouble Diagnosis Items Unit Standards Purposes Remarks Cooling Cycle Heavy Repair Summary Of Heavy Repair Process Contents Tools Items Precautions Precautions During Heavy Repair Inserting a capillary tube When replacing a drierWhen replacing a compressor Practical Work For Heavy Repair Calculation of amount of refrigerant charged Pipe ConnectionVacuum Sequence Charging sequence 12-0mm Standard Regulations For Heavy Repair Europe & CIS / America Brazing Reference DrawingsAsia / Middle-East Africa Explain general principles of sounds Problems Checks and MeasuresExplain the principles of temperature change Sound depends on the installation location Explain the principles of water supplied to dispenser Explain the procedure and principles of ice maker operationExplain the flow of refrigerant Explain the characteriistics of moving parts Measures for Symptoms on Temperature Explain the basic principles of frost formation Check the temperature control button and set at strongOdor and Frost Explain the basic principles of food odor Others Remove a freezer door HOW to Disassemble and Assemble Handle InsertTubeLineColletClip Assembly COVER, Dispenser Exploded View Optional part Ref No. GR-P227/GR-P257 Ref No. GR-L227/GR-L257 Freezer Compartment Optional part Refrigerator Compartment Machine Compartment ICE & Water Part Dispenser Part No JD8999A