We recently had a transformer blow in our neighborhood and now my 3 year old is asking me how it works and I honestly don’t know. Can anyone electrical transformers?
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Transformers require alternating current (AC) to operate. That is to say, the voltage/current cannot remain constant, it needs to always be changing. Like the voltage coming out of your wall sockets, which fluctuates in a sine wave 60 times per second (in the USA).
In a transformer, the voltage supply input wire (the “primary”) is typically wound around a core of something like iron. As the voltage/current changes, it creates a magnetic field in the core which is also changing.
The output wire, the “secondary”, is also wound around the same core. That changing magnetic field caused by the primary induces a current in the secondary. The power is transformed from a current, into a magnetic field, and then back into a current.
Those conversions depend on a few factors, one of which is how many times the wires are wrapped around the core. So by changing the ratio of primary/secondary windings, we can also transform the voltages! If the secondary windings end up with a higher voltage than the primary, we call it a “step-up” transformer. If the primary is higher voltage than the secondary, we call it a “step-down” transformer. If they are the same, it’s just an “isolation” transformer.
You can even make transformers with multiple secondaries and get various voltages out of the different ones.
The transformer in your neighborhood was transforming the high voltage transmission levels down to those used in the various houses. High voltage is typically used for transmission because less of the power is lost that way.
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