Medium Frequency Inverter Resistance Spot Welder Controller | High Precision MF Welding Power Supply

Medium Frequency Spot Welder Series

1. Product Structure

This medium frequency inverter resistance welding machine mainly consists of medium frequency inverter welding power supply, pneumatic welding cylinder and electric control system. It adopts single power unit matched with single welding head for discharge welding operation.

2. Core Advantages of Medium Frequency Inverter Resistance Welding Machine

Comparison Between MF Inverter Welder & Traditional Power Frequency AC Welder

Comparison Item	Traditional Power Frequency AC Welding Machine	Medium Frequency Inverter DC Welding Controller
Working Performance	Adjust transformer secondary output via thyristor firing angle; low power factor. Regulation cycle reaches 20ms under 50/60Hz grid.	Converts 3-phase AC to DC, then inverts to medium frequency current via IGBT; power factor over 90%. 1kHz inversion frequency, 1ms ultra-fast adjustment speed (20x quicker than AC models). Higher control precision & stable output.
Power Grid Adaptation	Single-phase 380V input causes severe 3-phase current imbalance, high reactive power and grid pollution. Multiple machines need large-capacity transformers with extra cost.	Balanced 3-phase 380V input with full-wave rectification, high grid utilization rate, no extra transformer expansion required.
Welding Energy Control	Current crosses zero leading to discontinuous heating, concentrated heat loss and unstable weld quality. Grid voltage fluctuation & secondary inductance greatly disturb welding current.	Pure DC welding current without zero crossing; concentrated heat reduces energy consumption. Anti-interference against grid fluctuation, less spatter, extended electrode service life. Secondary loop inductance has negligible influence on welding effect.
Welding Transformer	50/60Hz low-frequency transformer, bulky size, high power loss and low efficiency under equal power capacity.	1kHz medium frequency transformer, compact volume, low loss and high efficiency, easy installation.

General Superiorities of MF Inverter Welding Equipment

Beyond the above comparison merits, medium frequency inverter spot welders support diversified welding parameters and compatible materials, including galvanized steel, coated steel, stainless steel, aluminum and dissimilar metal sheets. The flexible welding characteristic enables wide application across hardware, electronics, new energy and automotive industries.

3. Main Functional Features of Welding Controller

• Wide adjustable output frequency range: 15–400Hz, millisecond-level time control precision
• Stores up to 32 groups of independent welding specifications, expandable to 256 groups
• 3-stage heating craft: preheating, welding and tempering; customizable current ramp-up/ramp-down curve & circulation times during welding
• Multi-group programmable I/O output ports, seamless connection with PLC and welding robots
• RS485 communication & BCD code control, supporting remote monitoring and automatic production management
• Real-time secondary current feedback closed-loop control, current control accuracy up to 5‰
• Built-in fault alarm recording function for quick historical failure inquiry

4. Standard Technical Parameters of IAW Series MF Welding Controller

• Basic Electrical Specifications

Item	Specification
Inverter Type	Medium Frequency AC
Input Power	3-phase 380V, voltage tolerance +10%~-20%, 50/60Hz±1%
Control Mode	Constant Primary Current / Constant Conduction Angle
Inversion Frequency	15–400Hz
Solenoid Valve Output	DC24V±10%, single channel max current ≤0.15A; standard 4 air valves, 10 valves for seam welding
Communication Interface	RS485
Max Storage Welding Program	32 groups (expandable to 256)
Cooling Water Demand	6–12L/min, pressure ≥0.15MPa, water temperature ≤40℃
Working Environment	Ambient temperature: -5℃~50℃ (water cooling); Humidity ≤80%; Max altitude 1000m; Insulation Class F
Housing Size	Standard size, customized dimension acceptable

• Model Matching Parameter Table

| Model | Max Primary Output Current | Matching Transformer Capacity | Secondary No-Load Voltage | Air Switch Size | Secondary Current Range |

| IAW-300L | 350A | 80KVA | 11.25V | 100A | 0–20KA |

| IAW-400T | 500A | 100KVA | 11.25V | 125A | 0–25KA |

| IAW-600T | 600A | 120KVA | 11.25V | 125A | 0–30KA |

| IAW-800T | 900A | 180KVA | 11.25V | 160A | 0–40KA |

| IAW-900T | 1000A | 200KVA | 13.5V | 160A | 0–45KA |

| IAW-1400T | 1600A | 250KVA | 13.5V | 200A | 0–50KA |

| IAW-1800T | 2000A | 300KVA | 13.5V | 200A | 0–60KA |

| IAW-2800 | 3000A | 350*2KVA | 13.5V | 400A | 0–70KA |

• Welding Time & Current Adjustable Parameters

All time parameters support 0–9999ms adjustable range: Pre-pressure Time, Pressure Hold Time, Cooling Time, Idle Time, Welding Hold Time;

• Segment heating time: Preheat Time 0–999ms, Temper Time 0–999ms;
• Current ramp curve: Ramp-up / Ramp-down Time 0–99ms;
• groups independent welding current available:
• CC1: Primary Constant Current (0–9999A)
• CC2: Secondary Constant Current (0–99.99KA)

5. 7-inch Touch Screen Control Panel

• Equipped with industrial 7-inch touch screen for one-stop parameter setting, function switching and real-time data monitoring, including welding current, transformer voltage and running status. All operation steps can be finished directly on touch screen without extra control unit.

6. Operation Interface Introduction

• Working Status Screen: Auto displayed after power-on; welding operation is only available under this interface
• Parameter Setting Screen: Configure all welding craft parameters
• Function Setting Screen: Support single/continuous welding, seam welding mode, constant current selection, water flow & temperature protection, electrode dressing and cycle welding function configuration

Medium Frequency Spot Welder Series