Autotransformer is another type of transformer, which is different from the isolation transformer in terms of working principle and application. Autotransformers do not have the same stringent requirements for electrical isolation as isolation transformers because their primary function is voltage conversion rather than providing electrical isolation.
The working principle of autotransformer is as follows:
1. Single coil: The autotransformer has only one coil, unlike the isolation transformer which has two independent coils. This coil is usually divided into two parts, one part is the input side (high voltage side) and the other part is the output side (low voltage side).
2. Shared turns: The input side and the output side share a part of the turns in the autotransformer. In other words, the two sides are connected by sharing the same part of the coil.
3. Voltage conversion: The autotransformer realizes the voltage conversion function by sharing a part of the coil. When a high voltage is applied to the input side, the number of turns in the common section causes a relatively low voltage to be produced on the output side.
4. Turns ratio: The voltage transformation ratio of the autotransformer depends on the number of turns shared by the input side and the output side. The transformation ratio is equal to the ratio of the number of turns in the common part to the total number of turns in the entire coil.
