Lincoln Electric SVM141-A service manual Output Rectification Control Board and Feedback

Page 35

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

E-3

E-3

THEORY OF OPERATION

FIGURE E.3 – OUTPUT RECTIFICATION, CONTROL BOARD AND FEEDBACK

 

 

BY-PASS

 

 

BOARD

 

POLARITY

WORK

 

 

 

SWITCH

ELECTRODE

 

 

MAIN

 

HI-FREQUENCY

TRANSFORMER

 

TRANSFORMER

RECONNECT

INPUT

 

 

 

 

 

 

 

POWER

 

 

 

 

 

 

 

PANEL

SWITCH

 

 

 

 

 

 

C

 

 

 

 

 

 

 

 

 

 

H1

 

 

 

 

 

H

 

 

X1

AC

DC+

 

 

O

 

 

 

 

 

 

 

 

 

 

K

 

 

 

 

SCR

 

 

 

 

 

 

BRIDGE

 

 

E

 

 

H2

X2

 

 

SHUNT

HIGH VOLTAGE

 

 

 

AC

DC-

TRANSFORMER

 

 

H3

 

 

 

 

 

 

 

 

 

F

CIRCUIT

 

 

 

 

 

 

 

 

 

 

H4

 

 

 

 

E

 

 

 

23VAC

 

 

 

E

 

 

 

 

 

 

 

D

 

 

 

 

 

 

 

 

B

 

 

 

 

 

 

 

 

A

 

"A"

 

 

 

 

 

 

C

 

 

 

 

 

 

 

K

 

 

 

 

18VAC

 

 

 

 

115VAC

 

 

 

18VAC

 

 

CONTROL

MODE

115VAC

 

 

 

SWITCH

 

115VAC

 

 

BOARD

 

RECEPTACLE

 

 

 

 

 

 

 

 

THERMAL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LIGHT

 

 

FAN

 

 

 

 

 

THERMOSTATS

 

 

 

 

 

 

 

 

 

 

REMOTE

 

 

 

 

 

 

 

 

RECEPTACLE

DOWNSLOPE GAS

POSTFLOW

BALANCE

OUTPUT

 

 

 

 

 

 

CONTROL

VALVE

CONTROL

CONTROL

CONTROL

OUTPUT RECTIFICATION,

CONTROL BOARD AND FEEDBACK

The AC output from the main transformer secondary is rectified and controlled through the SCR bridge. Output current is sensed at the shunt as a low voltage signal and fed back to the control board. The control board senses the status and settings of the various operator controls such as the mode switch, the output control, the remote control receptacle, the downslope control, the balance control and the postflow control. Circuitry on the control board evaluates these com- mands, compares them to the feedback information received from the shunt and sends the appropriate gate firing signals to the output SCR bridge. The control board regulates the firings of the output SCRs, which control the output of the machine. See SCR Operation. The control board also monitors the ther- mostats and controls the gas solenoid, the thermal light and the cooling fan.

SQUARE WAVE TIG 275

Image 35
Contents Square Wave TIG Safety Depends on YouSquare Wave TIG SafetyFumes and Gases can be dangerous Electric Shock can killARC Rays can burn Iii Cylinder may explode if damagedSûreté Pour Soudage a L’Arc Précautions DE SûretéMaster Table of Contents for ALL Sections Table of Contents Installation Section Technical Specifications Square Wave TIG InstallationSafety Precautions Figure A.1 Input Supply ConnectionsReturn to Section TOC To Section TOC Input Reconnect ProcedureTable A.1 User Supplied ConnectorsOutput Connections Work Cable ConnectionCylinder could explode if damaged TIG Torch ConnectionTWIST-MATE Adapter for LW-18 and LW-20 TIG Torch TWIST-MATE Adapter for LA-9 and LA-17 TIG TorchCompleted Assembly Square Wave TIG Table of Contents Operation Section Welding Sparks can cause fire or explosion OperationElectric Shock can kill Fumes and Gases can be dangerousRecommended Processes and Equipment Design Features AdvantagesGeneral Description Limitations Welding CapabilityFigure B.1 Control Panel Controls and SettingsTwist Mate Electrode Welding OperationTIG Welding TIG Welding GuidelinesTIG Welding Sequence of Operation 4-Step TIG Mode TIG Welding Sequence of Operation 2-Step TIG ModeTable B.2 Recommended Polarity Settings for TIG Welding AC Wave Balance and Auto Balance Advanced TIG Welding FeaturesHand and Foot Amptrol Operation 50/60 Hertz European Machines Auxiliary PowerStick Welding Hertz Domestic MachinesSquare Wave TIG Section C-1Section C-1 Table of Contents AccessoriesK963-1, -2 Hand Amptrol Accessories Included with MachineOptional Accessories Table of Contents Maintenance Section Overload Protection MaintenanceRoutine and Periodic Maintenance Display PC BOARD, ARC STARTER/BYPASS PC Board Component Location and AccessSpark GAP ASSEMBLY, High Voltage Transformer Control PC BoardFigure D.2 Major Component Locations Table of Contents Theory of Operation Section Theory of Operation Input Power CircuitFigure E.3 Output RECTIFICATION, Control Board and Feedback Output Rectification Control Board and FeedbackFigure E.4 High Voltage / High Frequency Circuit High Voltage / High Frequency CircuitFigure E.5 DC Welding Output DC Welding OutputFigure E.7 AC Welding Output AC Welding OutputFigure E.9 SCR Operation SCR OperationOverload Protection Protective CircuitsThermal Protection Table of Contents Troubleshooting & Repair Section High Voltage / High Frequency can damage test equipment Troubleshooting & RepairHOW to USE Troubleshooting Guide Disable ProcedurePC Board can be damaged by static electricity PC Board Troubleshooting ProceduresDetailed in the beginning of this manual Troubleshooting GuideObserve Safety Guidelines Perform the SCR Bridge Test Troubleshooting & Repair Connections Troubleshooting Guide Troubleshooting & Repair TIG Welding Problems Can Kill Electric ShockTroubleshooting & Repair To Technical Specifications Stick Welding Problems 15F-15 Function ProblemsFunction Problems Installation Troubleshooting & Repair Materials Needed High Frequency Circuit Disable ProcedureTest Description Procedure High Frequency Circuit Disable ProcedureT1 Main Transformer Test T1 Main Transformer Test Test ProcedureReplace the case side covers Primary WINDINGS1 Test PointsGAS Water Solenoid Test Figure F.3 GAS Solenoid Location GAS Water Solenoid TestStatic SCR Test Figure F.4 Plug J1 Location on Control Board Static SCR TestAssembly Removal and Replacement Description Active SCR TestFigure F.6 Plug J1 Location on Control Board Active SCR TestFigure F.7 Active SCR Test Setup SCR Bridge Assembly Removal and Replacement Normal Open Circuit Voltage Waveform AC TIG ModeScope Settings DC TIG Mode AC Stick Mode DC Stick Mode AT 30 VAC Typical Output Voltage Waveform Machine LoadedMachine Loaded to 255 Amps AT 31 VDC Machine Loaded to 275 AmpsAC Stick Mode DC Stick Mode 50 V/Div High Voltage Transformer Removal Replacement High Voltage Transformer Removal ReplacementRemoval Procedure Figure F.10 High Voltage Transformer Mounting Insulators Replacement ProcedureSCR Bridge Assembly Removal and Replacement Using the 3/8 nut driver, remove the case SCR Bridge Assembly Removal and ReplacementFigure F.13 SCR Bridge Connections Refer to Figures F.11 F.13 Polarity Switch Removal and Replacement Allen Screw Control Knobs Polarity Switch Handle Polarity Switch Removal and Replacement253 POS Micro Switch Leads Square Wave TIGFigure F.16 Polarity Switch Wiring Diagram For Steps 9--17, see Figure F.15 and F.16 Replacement ProcedureDescription Removal and Replacement Main Transformer and Output Choke AssemblyFigure F.18 Transformer Connections POS Micro Switch Leads Figure F.19 Polarity Switch Connections Choke NEGRefer to Figures F.17 F.19 Reassembly ProcedureOpen Circuit Voltages Minimum Acceptable Output Voltage AT Maximum Output SettingRetest After Repair Input Idle AmpsSquare Wave TIG Section G TIG WiringDiagram L10747 ElectricalSquarewave Diagram L10747-2Control Board Schematic G3358-1 Electrical DiagramsOCI4 TRI3 MT2 Control Board Schematic G3358-2Return to Section Return to Section TOC To Section TOC Display Board Schematic L10768Bypass L10770-17-24-98 Display Board Layout L10770-1XXX 10G-10 Bypass Board Layout L10121-1Square Wave TIG

SVM141-A specifications

The Lincoln Electric SVM141-A is a cutting-edge solution designed for operators requiring precision, efficiency, and versatility in their welding applications. This machine is known for its compact form but robust feature set, making it an ideal choice for both professional welders and industrial applications.

One of the standout features of the SVM141-A is its advanced inverter technology. This innovation allows for a stable arc, providing consistent results even under varying conditions. The machine minimizes power consumption, making it energy-efficient without compromising performance. The inverter technology also supports a wider input voltage range, making the SVM141-A suitable for use in diverse environments and job sites.

Another key characteristic is its multi-process capability. The SVM141-A supports MIG, stick, and TIG welding processes, providing flexibility for various welding tasks. This versatility enables operators to tackle different materials, including mild steel, stainless steel, and aluminum, making it a valuable tool for numerous projects.

The user-friendly interface of the SVM141-A includes an intuitive digital display, which allows welders to adjust settings with ease. This feature is crucial for ensuring the right configurations for specific welding tasks, reducing the chances of errors and enhancing the overall finish of welds.

Safety is also a priority with the Lincoln Electric SVM141-A. It comes with built-in safety features such as overheat protection and automatic shutdown, ensuring operator safety and equipment longevity. The machine's lightweight design enhances portability, allowing it to be used in various workspaces with ease.

Durability is another hallmark of the SVM141-A. Constructed with high-quality materials, the machine is designed to withstand the rigors of demanding work environments. This ensures reliability over time, providing consistent performance even under heavy use.

In summary, the Lincoln Electric SVM141-A is a versatile, efficient, and user-friendly welding machine that appeals to a wide range of users. Its advanced inverter technology, multi-process capabilities, safety features, and durable construction make it a strong contender in the welding market, suitable for both professionals and hobbyists alike. Whether it’s for light fabrication, repairs, or industrial welding tasks, the SVM141-A meets diverse needs with precision and reliability.