UL Standards & Engagement Isolating Signal and Feedback Transformers for Use in Electronic Equipment UL 1876

1.1 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. 1.2 These requirements do not apply to transformers and motor-transformers that are connected to a supply circuit to power a secondary circuit.