Direct current medium frequency welding.
Ordinary welders use a single-phase welding transformer that supplies alternate welding current; the welding current is adjusted by the thyristors by means of the phase-shift technique.
This new technology employs an inverter supplies by the three-phase mains.
Inside the inverter the current is rectified, filtered by the capacitors and transformed by an IGBT bridge into alternate current at medium frequency (1000Hz).
It is used a specific welding transformer equipped with a rectifier that supplies direct welding current. Advantages provided by medium frequency welding.
Current is affected neither by the dimensions of the secondary circuit nor by the ferrous material inside the secondary circuit itself nor by the heating of the welding machine nor by the variations of the mains voltage.
The welding current is supplied continuously and constantly.
The fusion area heats up in a more homogeneous way improving the quality obtained.
Costant an accurate welding current.
The adjustment in millisec. allows the best welding time set-up.
Welding time reduction that allows an increase in productivity.
Reduction of the used welding current. The electrodes lifetime is longer and a less required maintenance allows a better productivity.
This effect is particularly emphasised on aluminium and galvanized sheets spot welding.
Improved weldability of unlike and highly conductive materials.
Aesthetically improved results due to a minor deformation of the piece to be welded and to a reduced electrode indentation.
Reduced possibility that melted material spatters during the welding process.
High speed of welding current rise.
Allows to weld the materials more easily and to solve problems of difficult welding.
Reduced electric consumption.
Reduced current absorption, balanced on the three phases.
Reduced installation costs and improved power factor (cos φ).
Therefore, the inverter technology involves a remarkable improvement of the welding quality, an extreme precision of the welding time and current, a higher productivity and reduction in costs. As a result, inverter technology offers many advantages: a higher welding quality, an extreme precision in time and current, improved productivity and reduction in costs.
