Weld Master India

wmi pneumatic ac spot welding machine 10 kva to 200 kva

An MFDC Spot Welding Machine (Medium Frequency Direct Current) is a type of resistance spot welding machine that uses medium-frequency (typically 1,000 Hz) AC input, which is then converted to DC output for the welding process. This technology is widely used in the automotive industry and other manufacturing sectors where precision, speed, and repeatability are critical.

1. MFDC Inverter Controller

   • Converts 50/60 Hz AC to 1,000 Hz AC, then to DC.

   • Allows precise control over weld time, current, and energy.

2. Transformer

   • Lightweight and compact due to high-frequency operation.

   • Converts medium-frequency AC to low-voltage, high-amperage DC.

3. Welding Electrodes

   • Copper alloy tips that apply pressure and conduct current.

4. Servo or Pneumatic Actuator

   • Applies consistent force to the workpieces during welding.

5. Cooling System

   • Usually water-cooled to prevent overheating.

1. Clamping: Electrodes clamp two metal sheets together.

2. Current Application: A short, high-amperage DC current is passed through the joint.

3. Resistance Heating: Heat is generated at the contact point due to electrical resistance.

4. Weld Nugget Formation: Metal melts and fuses at the interface.

5. Cooling: Current stops, and pressure is maintained for cooling and solidification.

• Automotive body assembly (BIW - Body in White)

• Battery tab welding (e.g., EVs)

• Sheet metal joining

• Appliance manufacturing

• Requires specialized maintenance & setup

• Initial cost higher than traditional AC machines

• Water cooling is essential due to high heat