• Artech Welders Private Limited

Spot & Projection Welding Machines

Artech Welders Pvt Ltd offers medium frequency direct current (MFDC) Spot and Projection Welding Machines. These machines use an inverter, powered from a 3-phase supply in which the current is rectified using diodes and then chopped by means of IGBTs into high frequency alternating current. This alternating current is then transformed by the welding transformer and again rectified. DC current is thus obtained at the secondary side in to the parts to be welded. With MFDC welding, rise time is immediate. It is possible to create full-phase firing during the natural rise time to lessen the rise time. Control of upslope and post weld cycle is easily possible in these machines. Precise weld current control: MFDC welding utilises IGBTs for current switching. These units are turned on and off of 400-2000 times per second. By controlling this rate, one can get a wave form consisting of several individually shaped current impulses. This results in virtually splashless welding of components. Suitable for variety of applications: these machines are suitable for projection and spot welding of variety of applications, e.g., welding of coated sheets and dissimilar metal welding.
Advantages of medium frequency direct current:

• Energy savings – the MFDC machines require approximately 30% less power as compared to conventional AC welding machines
• Balanced load distribution – the MFDC welding machine load is evenly distributed across all three phases
• This allow equal load to be drawn from each line, thus reducing peak draw on any one line
• Improved and consistent power factor – the MFDC welder load appears to have unity power factor, which reduces the overall plant load and avoids possible penalties assessed by power companies
• Attains welding current immediately – standard DC welding utilises SCRs that have a rise time prior to steady state.