The purpose of this International Standard is to give specific details or to complement ISO 5826, which deals with general specifications applicable to all transformers, relating to particular transformers within its field of application.

Unless otherwise specified, those requirements of ISO 5826 not modified by this International Standard are applicable.

This International Standard applies to transformers with one secondary winding for multi-spot welding machines as used in the automobile industry. These transformers can substitute transformers covered by ISO 7284 for applications with current control. They can also replace transformers covered by ISO 7284 if only one secondary winding is used.

Transformers covered by this International Standard shall be designed as to

• allow separate control and regulation of one single secondary welding circuit;
• allow substitution of one transformer covered by ISO 7284 by two transformers covered by this International Standard.