It seems like you've mentioned "Potential Transformers" (P.T.) in the context of transformers. However, your input is a bit unclear. "Potential Transformers" are also known as "Voltage Transformers" (VT) or "Potential Transformers (PT)." These are electrical devices used in power systems to measure voltage levels accurately. They are a type of instrument transformer that steps down high voltage levels to a lower and manageable level for measurement and protection purposes. Potential Transformers are commonly used to provide inputs to instruments such as voltmeters, protection relays, and other voltage-sensitive devices.
If you're looking for more information about Potential Transformers or have specific questions about them, please provide more details so I can assist you better.