IEC 61558-2-16:2009+A1:2013 deals with the safety of switch mode power supply units and transformers for switch mode power supply units. Transformers incorporating electronic circuits are also covered by this standard. It is based on the second edition (2005) of that standard. This first edition of IEC 61558-2-16 cancels and replaces IEC 61558-2-17, published in 1997. It constitutes a technical revision. This part has the status of a group safety publication in accordance with IEC Guide 104 (1997): The preparation of safety publications and the use of basic safety publications and group safety publications. This consolidated version consists of the first edition (2009) and its amendment 1 (2013). Therefore, no need to order amendment in addition to this publication. This publication is to be read in conjunction withIEC 61558-1:2005.