IEC 61558-2-7 Ed. 3.0 b:2023

This part of IEC 61558 deals with the safety of transformers for toys and power supply units incorporating transformers for toys. Transformers for toys incorporating electronic circuits are also covered by this document.

NOTE 1 Safety includes electrical, thermal and mechanical aspects.

Unless otherwise specified, from here onward, the term transformer covers transformers for toys and power supply units incorporating transformers for toys.

This document is applicable to stationary and portable single-phase, air-cooled (natural or forced) dry-type transformers. The windings can be encapsulated or non-encapsulated.

This document is applicable to independent transformers and transformers for specific use.

For power supply units (linear) this document is applicable. For switch mode power supply units IEC 61558-2-16 is applicable together with this document. Where two requirements are in conflict, the most severe takes precedence.

The rated supply voltage does not exceed 250 V AC. The rated supply frequency and the internal operating frequencies do not exceed 500 Hz.

The rated output does not exceed 200 VA and a rated output current does not exceed 10 A.

The no-load output voltage does not exceed 33 V AC or 46 V ripple-free DC, and the rated output voltage does not exceed 24 V AC or 33 V ripple-free DC.

In general, this document does not take into consideration children playing with the transformers.

This document is not applicable to external circuits and their components intended to be connected to the input and output terminals or socket-outlets of the transformers.

Attention is drawn to the following if necessary:
• for transformers intended to be used in vehicles, on board ships, and aircraft, additional requirements (from other applicable standards, national rules, etc.);
• measures to protect the enclosure and the components inside the enclosure against external influences such as fungus, vermin, termites, solar-radiation, and icing;
• the different conditions for transportation, storage, and operation of the transformers;
• additional requirements in accordance with other appropriate standards and national rules can be applicable to transformers intended for use in special environments;
• for transformers for toys intended to be used as a battery charger for use with children additional requirements can apply.

Future technological development of transformers can necessitate a need to increase the upper limit of the frequencies. Until then this document can be used as a guidance document.

This group safety publication focusing on safety guidance is primarily intended to be used as a product safety standard for the products mentioned in the scope, but is also intended to be used by technical committees in the preparation of publications for products similar to those mentioned in the scope of this group safety publication, in accordance with the principles laid down in IEC Guide 104 and lSO/lEC Guide 51.

One of the responsibilities of a technical committee is, wherever applicable, to make use of basic safety publications and/or group safety publications in the preparation of its publications.