Medium frequency transformer technology is becoming ever more widely used in spot welding applications.

The main benefits are:-

• Size & weight
  • 1000Hz operation greatly reduces size & weight of transformers.
  • This gives better manoeuvrability for manual guns and faster robot speeds in automated applications
• Welding quality
  • Improved spot welding characteristics – the weld current is DC, so the energy is applied more smoothly and faster.
  • Welding times can generally be reduced, with a commensurate increase in production speed.
• No inductance losses for large weld guns.
  • With conventional AC guns, when large arms are required, large transformers must be used to overcome these losses. This increases gun weight still further.
  • With DC secondary current. Losses from MF transformers are minimal. A 70kVA transformer will still deliver 18kA even in the largest weld gun.
• Balanced power load.
  • As the control uses all 3 phases to generate the waveform to the transformer, the mains load is evenly balanced, reducing cable sizes & fuse ratings.
• Accurate weld timing for precision welding
  • For applications where precision is the key, weld controls can set the weld time to the nearest milli-second. Conventional AC controls allow time setting only to the nearest 1/100 second.