IEC 61558-2-7:2007

Overview

IEC 61558-2-7:2007 is an international standard developed by the International Electrotechnical Commission (IEC). This standard specifies the particular safety requirements and tests for transformers and power supplies intended for use with toys. As part of the IEC 61558 series, which deals with the safety of power transformers, power supply units, reactors, and similar products, Part 2-7 focuses specifically on ensuring electrical, thermal, and mechanical safety for products that may be used in environments where children are present.

This second edition of IEC 61558-2-7 updates and replaces the previous 1997 version, aligning the safety requirements with the latest edition of IEC 61558-1 and broadening the scope to include power supplies for toys.

Key Topics

IEC 61558-2-7:2007 covers essential safety requirements and testing methods for toy transformers and associated power supplies, including:

• Product Scope: Applies to both stationary and portable, single-phase, air-cooled (either naturally or forced), dry-type transformers and power supplies for toys.
• Electrical Ratings:
  • Maximum input voltage: 250 V (AC)
  • Maximum frequency: 500 Hz
  • Maximum output: 200 VA (volt-amperes)
  • Maximum output current: 10 A
  • No-load output voltage: up to 33 V AC or 46 V ripple-free DC
• Construction Types: Covers both encapsulated (potted) and non-encapsulated windings.
• Safety Classes and Protection:
  • Requires class II construction for electric shock protection.
  • Differentiates between short-circuit-resistant transformers, those protected by an internal device, and fail-safe types.
• Marking and Instructions: Specifies marking requirements, including necessary symbols, operating instructions, and IP ratings for devices intended for outdoor use.
• General and Mechanical Testing: Outlines mechanical strength, resistance to heat and fire, dielectric properties, and ingress protection against dust, solids, and moisture.

Applications

IEC 61558-2-7:2007 is used by manufacturers, testing laboratories, regulatory authorities, and product designers involved in the production and certification of:

• Toy power transformers: Devices supplying reduced voltage to electrical toys to ensure child safety.
• Power supplies for toys: Units converting mains voltage into lower, safe voltages for toy operation.
• Related electronic circuits: Any power supply incorporating a transformer designed specifically for toys.

Examples include toy train power packs, remote-controlled car chargers, electric building block sets, and any power adapter labeled for toy use.

By adhering to this standard, manufacturers demonstrate compliance with recognized international requirements, supporting both product safety and market access globally.

Related Standards

IEC 61558-2-7:2007 is a group safety publication and should be applied in conjunction with related standards to ensure full compliance and safety. Relevant standards include:

• IEC 61558-1 – General requirements for safety of power transformers, power supplies, reactors, and similar products.
• IEC 60227-1 – Polyvinyl chloride insulated cables (up to 450/750 V) for use within these devices.
• IEC 60245-1 – Rubber insulated cables (up to 450/750 V).
• IEC Guide 104 – Guidance on the development and use of safety publications.
• IEC 60417-5219 – Graphical symbols for transformers for toys.

National standards or additional requirements may also apply when transformers and power supplies are used in special environments (e.g., vehicles, ships, tropical climates).

Practical Value

Adopting IEC 61558-2-7:2007 brings several benefits:

• Ensures electrical safety for children using powered toys, reducing accident risks.
• Helps manufacturers and suppliers access international markets by complying with IEC requirements.
• Guides product design to include adequate labeling, instructions for safe use, and robust construction against mechanical and environmental factors.
• Supports regulatory compliance and facilitates product certifications and approvals worldwide.

By following IEC 61558-2-7, stakeholders can be confident that transformers and power supplies for toys meet stringent international safety criteria, protecting users and simplifying market acceptance.