Auto Vs Power Transformer

A power transformer is a general term for a transformer used to transfer power rather than a signal. That can be in a large power distribution system, a small DC to DC converter or any number of things.

An auto transformer is a specific type of transformer using a single winding with a tap on one of the turns. They are typically used as power transformers but I imagine they could be used as a signal transformer if one wanted to.

Going into further detail is a waste of time until you put forth the effort to do some research on your own. It would require me to spend time think through and accurately writing things that are already written down. It would save you time but waste mine. Do some research on auto transformers and you will find several well written articles. Then ask specific questions.

Any transformer used to convert power is a power transformer. An autotransformer is often used as a power transformer in non isolated flyback configurations.

An auto transformer is a transformer that interconnects 2 different grids.

Thank you all gentlemen for your replies.

I need to read more about it on the net.

regards

The Auto trasnformers are normally connected to interconnect 2 different grids of different voltages . Both the windings are in Star ( for pOwer transformer ) and itr has only 1 neutral

- R K Mohapatra-

"Power Transformer" is too generic of a term. Perhaps a better question would be "What is the difference between an Autotransformer and an Isolation Transformer?"

As mentioned above, an Autotransformer consists of a single winding around an iron core, which creates a change in voltage from one end to the other. In other words, the self-inductance of the winding around the core changes the voltage potential, but there is no isolation of the high and low voltage ends of the winding. So any noise or other voltage anomaly coming in on one side is passed through to the other. For that reason, Autotransformers are typically only used where there is already some sort of filtering or conditioning ahead of it, as in electronic applications, or the downstream device is unaffected by those anomalies, such as an AC motor during starting. The only reason people use them over Isolation Transformers is because they are cheaper and if isolation has already been done somewhere else, there is often no further reason to do it again.

The opposite of an Autotransformer is an Isolation Transformer, where there are two distinct sets of wndings around a common iron core, but with no physical connection between the circuits. So the primary induces a voltage onto the secondary, but there is inherent separation between the two circuits in terms of noise and other anomalies. These types of transformers (in one form or another) are used basically everywhere else that an Autotransformer is inapropriate for.