Double-sided spot welding and spot welding is usually divided into two major categories of single-sided Welding Electrode. Double-sided spot welding, the electrode from the workpiece to the welding of both sides of the feed. A typical two-sided spot welding as shown in Figure 11-5. Figure A is a most common way, when both sides of the workpiece electrode indentation. Figure b with a large welding area that the conductivity of the electrode plate to do next, so you can eliminate or reduce the following parts of the indentation. Commonly used in the decorative panel spot. Figure c is the same spot welding two or more double-sided spot welding, use a transformer to the electrodes in parallel, then, all of the current path impedance must be basically the same, and each welded parts of the surface state, material thickness of the electrodes are subject to the same pressure, in order to ensure that the current through the various joints are basically the same. Figure d is more than double the use of multiple transformers little welding, to avoid c deficiency.

Single-sided spot welding, electrode welding by the workpiece at the same side feed, a typical single-sided spot welding as shown in Figure 11-6, Figure A is a single-sided single little welding, the electrode is not used to form solder joints large diameter and large contact surface to reduce the current density. Figure b is the non-diversion of dual-sided little welding, the welding current at this time all through the welding zone. Figure C has little diversion of dual-sided welding, the current does not flow through the top of the workpiece through the Stainless Steel Electrode, the formation of romantic. In order to provide low resistance welding current path, the workpiece underneath the copper plate. Figure d is the distance l when two large joints, such as during re-board the frame components and welding, in order to avoid undue heating caused by board warpage and reduce re-resistance between two electrodes, using a special copper bridge A, with the electrode at the same time pressed in the workpiece.

In mass production, the single multi-point welding is widely available. At this time can be powered by a transformer, the turns of the electrode to suppress the workpiece type (Figure 11-7a), also can be used by each of the electrodes separate transformer power supply, all the electrodes simultaneously press and hold the workpiece type (Figure 11-7b). the latter type has a number of advantages, applications are more widely used. Its advantages are: the transformer can be placed as close to the joint electrode recently, so.

Its power and size can significantly reduce; various joints of the process parameters can be adjusted individually; can weld all the joints, high productivity; all electrodes simultaneously press and hold the workpiece, to reduce distortion; more than one power transformer at the same time, to ensure the three-phase load balancing.