Characteristics of the secondary circuit
The dimensions of the secondary circuit in secondary loop determine to a large extent, the performance of these machines. The secondary loop is roughly equal to the throat area. The impedance of all the parts in the secondary loop except the weld surface should be as low as possible so that the losses are less. The materials used in the secondary circuit should have a low electrical resistivity and the dimensions of the conductors must be just enough to carry the current. The throat depth and height of the machine should be just x duty cycle sufficient as to accommodate the maximum size of the job to be welded with that machine. The magnetic materials interposed between the arms and horns of the machine reduces the secondary current in relation to the thickness of the material the extension of steel work metal or fixtures into the secondary loop should be kept to a minimum.