A transformer is a device that changes an electrical voltage or current from one level to another. (In radio frequency applications, it is used to couple the RF electronic circuits.)
Transformers are used to:
- Convert high voltage alternating current (AC) to desired low voltage alternating current (AC). Such transformers are called step down transformers.
- Convert low voltage alternating current (AC) to desired high voltage alternating current (AC). Such transformers are called step up transformers.
- Electrically separate one part of the circuit (or any other electrical system) from the other part, termed as 'electrical isolation'. Such transformers are called isolation transformers.
The transformation may involve the loss of some power as waste heat.
(see related question)
