autotransformaatissa

Autotransformaatissa is a Finnish term that translates to "autotransformer" in English. An autotransformer is a type of electrical transformer that uses only one winding, which is common to both the primary and secondary circuits. This single winding is tapped at one or more points to provide the desired voltage conversion. Unlike a conventional transformer, which has separate primary and secondary windings, an autotransformer relies on both conductive and inductive coupling between the input and output.

The primary advantage of an autotransformer is its smaller size and lower cost compared to a conventional transformer of the same power rating, especially when the voltage transformation ratio is close to one. This is because less copper is used in its construction. However, autotransformers also have a significant drawback: there is no electrical isolation between the primary and secondary circuits. This means that if a fault occurs, the higher voltage from the primary side can directly transfer to the secondary side.

Autotransformers are commonly used in applications where electrical isolation is not critical, such as in power distribution systems for voltage adjustment, motor starting, and in audio equipment. They can be used to step voltage up or down. The efficiency of an autotransformer is generally high, especially at low voltage ratios. The absence of a separate secondary winding simplifies construction and reduces losses.