D（T）Z Secondary rectification spot (projection) welder series is a new type welder ,which incorporate large power silicon diode at the output of the secondary winding of the resistance welder transformer ,it can conver AC into DC for welding.

The secondary side is a DC circuit ,and indutive reactance can be omitted .When current outputs are the same , the power factor of welder can be greatly increased ,which can be up to 0.8 .The apparent power required of this type of welder is only 1/3-1/5 of onventional welder ,it has small impact on power grid.

DC heating can avoid both the heat loss occurred when AC amplitude ,and the splashingoccurred when peak current is overlarge .The skin effect produced when driect flow through strong magnetic metal can make weld point well formed .and it can also result in strong penetration ,ensuring welding quality even in the case of spot welding of multi-layer steel plates.

No alternative electro-magnetic force between two electrode arms, this enables the electrode’s pressure to be more stable; copper, aluminum and aluminum alloy, it can also be used for welding of rare metals such astitanium ,niobium.zirconoum and tantalum,etc .And multi-layer steel plates.