Theworkingprincipleofthecommonweldingmachineissimilartothetransformer,itisavoltage-downtransformer.Atthetwoendsofthesecondarycoilareweldedworkpiecesandelectrodes,ignitethearc,andheatsourceisgeneratedinthehightemperatureofthearctoweldthecracksoftheworkpieceandtheelectrode.Weldingtransformersh***etheirowncharacteristics,thatis,thecharacteristicsofsharpvoltagedrop.Thevoltagedecreaseswhentheelectrodeignitesandthevoltagedropssharplywhentheelectrodeisshort-circuited.Thereasonofthisphenomenonisthecorecharacteristicofweldingtransformer.)