Abstract: A pair of workpieces are welded together by passing between them an arc which is guided by a magnetic field to rotate on the workpieces. Immediately after striking of the arc the field strength of the magnetic field is relatively great and a relatively great current is similarly passed through the arc. During a subsequent main phase, before fusing of the surfaces to be welded, the field strength and the current of the arc are reduced to a fraction of their values for even heating of the surfaces to be welded together. Finally during a terminal phase the current of the arc and the field strength are again raised to a higher level to completely fuse the two surfaces which can then be welded together once the arc is interrupted.

Abstract: A method for monitoring and regulating electrical resistance welding by comparing the actual values obtained by integrating measured values of the welding electrodes with desired valued limits obtained by test welding operations in the form of voltage and current parameters. These parameters are integrated in accordance with the formula ##EQU1## WHEREIN Y IS OTHER THAN UNITY AND IS SELECTED SO THAT THE INFLUENCE OF THE RESISTANCE R on the actual, measured value is at least equivalent to the influence of the current I and/or the welding time t, in the above formula, on the measured value. The resultant weld value is then fed to a comparison circuit which contains the upper and lower limits obtained by the test welding. If these limits are exceeded the power to the welding apparatus is automatically disconnected.