UL Standard for Safety Isolating Signal and Feedback Transformers for Use in Electronic Equipment
|Publication Date:||17 May 2001|
These requirements apply to isolating signal and feedback transformers intended to be used in electronic equipment where only audio, video, and other signal waveforms are transformed. These transformers are intended to provide isolation from circuits that are either conductively connected to a branch circuit supply or connected to secondary circuits involving voltages that are considered to present a risk of electric shock by the nature of their use in an end-product.
These requirements do not apply to transformers and motor-transformers that are connected to a supply circuit to power a secondary circuit.
A product that contains features, characteristics, components, materials, or systems new or different from those covered by the requirements in this standard, and that involves a risk of fire or of electric shock or injury to persons shall be evaluated using appropriate additional component and end-product requirements to maintain the level of safety as originally anticipated by the intent of this standard. A product whose features, characteristics, components, materials, or systems conflict with specific requirements or provisions of this standard does not comply with this standard. Revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard.