An auto transformer specifically refers to that transformer where in a certain part of winding are common to both secondary as well as primary circuits. The primary circuit that is connected to secondary circuit via an electric circuit is in the same manner coupled with it in a magnetic format.
In case of consulting a copper core base, it is taken that both volume and area of copper is proportional to that cross-section of conducts which is to be taken into consideration in this case. Since it is current that determines the level of cross and turns, therefore copper’s weight is taken to be proportional to a combined product of current and the number of turns it makes.
Given its prevalence in the modern times, it is important to note its advantages, areas where it is used and its disadvantages.
Usages of auto-transformers:
- They help in regulating transformers
- It helps in regulating procedures in an electrical testing laboratory
- For getting proper furnace binding, it helps in getting supply as furnace transformers
- In case of a drop in voltage, it helps in boosting the distribution cable levels
- It helps in reaching a neutral point in case of an A.C. distribution system that is 3 tier
- In case of dealing with distribution and transmission circuits of multiple voltage levels, this auto-transformer helps in tying them up together
- For beginning with induction process and synchronizing motors that are present, a partial line voltage situation is to be found. With auto-transformer, this process becomes easier
These are the most common usages.
Advantages associated with auto-transformers:
The plus points are:
- In comparison to general 2 winding transformers, they help in regulating voltage in a better manner
- They come in a small size
- In comparison to general transformers, they are priced at a lower rate
Disadvantages associated with auto-transformers:
Though this has multiple benefits, but in certain areas, they tend to be placed behind.
- If the voltage ration in an auto-transformer increases by any chance, or due to regular process it can be seen that general winding is larger in comparison to the common coil that is present. Hence, it is only a small part of the area where economy is gained while using this auto transformer, while in the other parts its efficiency is reduced comparatively
- In comparison to conventional transformers, in an auto-transformer, both primary and secondary circuits are linked with each other. Hence, as a result of any disturbance on either side, there is stress on both these sides. For protecting that lower voltage side from influence of higher voltage level, proper insulation implementation is required. Also, to be noted that in case of a step-down transformer, this high voltage side influencing the lower voltage point can surely be found.
Due to this lack of economy as well as poor isolation levels, it is not used for rations at a general level apart from transformers with low voltage.