Autotransformer facts for kids
An autotransformer is a special kind of transformer that uses only one coil of wire. The word "auto" comes from Greek and means "self." This means the single coil works by itself, acting as both the input and output parts of the transformer.
Because it uses just one coil, an autotransformer is often smaller, lighter, and cheaper than other transformers. However, it does not completely separate the electrical circuits. This means there is a higher chance of a short circuit if something goes wrong.
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How Autotransformers Work
Autotransformers work by changing the voltage of electricity. They can either "step up" (increase) the voltage or "step down" (decrease) it. Imagine you have a long coil of wire. An autotransformer connects to different points along this single coil to get the desired voltage.
For example, if you want to step down voltage, you might connect the input across the whole coil. Then, you take the output from only part of the coil. If you want to step up voltage, you might put the input across part of the coil and take the output from the whole coil.
Where Are Autotransformers Used?
Autotransformers are used in many places where electricity needs to be adjusted.
Power Systems
They are often found in large power distribution systems. They help to connect different parts of the electrical grid that use slightly different voltages. For example, they can help change 110-120 V electricity to 220-240 V, or vice versa.
Everyday Uses
- Audio equipment: Some sound systems use autotransformers to match different parts.
- Rail transport: They are used in electric trains to manage power.
- Motor starting: Large electric motors sometimes use autotransformers to slowly increase the voltage when they start. This helps them start smoothly without drawing too much power at once.
- Variable voltage supplies: Some autotransformers can be adjusted to give a range of output voltages. These are often called "variacs" and are useful in labs or workshops.
Images for kids
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Variable Transformer - part of Tektronix 576 Curve Tracer
See also
In Spanish: Autotransformador para niños
