# How electric transformers work

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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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Converting between voltages is done by turning electrical energy into a different kind of energy, and then back.

The first way that came to mind for me when I was young was a motor and a generator connected together. The electricity into the motor becomes turning in the shaft, and then that becomes electricity in the other motor. By adding more or fewer coils to the generator, we can adjust the voltage that comes out, since the voltage from each coil adds together.

I was overcomplicating things, though. See, a motor actually turns electrical energy into magnetic energy, then the magnetism pulls on the shaft. We can skip the middleman and take the shaft out, having the motor’s electromagnets right by the generator’s electromagnets.

That’s all a transformer is. Two sets of coils, one input and one output, right next to eachother. The first coil generates a magnetic field from the electricity, and the second one picks it up turning it back into electricity. By adjusting how many loops is in each coil, we control the voltage that comes out.

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.

[removed]

[removed]

Converting between voltages is done by turning electrical energy into a different kind of energy, and then back.

The first way that came to mind for me when I was young was a motor and a generator connected together. The electricity into the motor becomes turning in the shaft, and then that becomes electricity in the other motor. By adding more or fewer coils to the generator, we can adjust the voltage that comes out, since the voltage from each coil adds together.

I was overcomplicating things, though. See, a motor actually turns electrical energy into magnetic energy, then the magnetism pulls on the shaft. We can skip the middleman and take the shaft out, having the motor’s electromagnets right by the generator’s electromagnets.

That’s all a transformer is. Two sets of coils, one input and one output, right next to eachother. The first coil generates a magnetic field from the electricity, and the second one picks it up turning it back into electricity. By adjusting how many loops is in each coil, we control the voltage that comes out.

Converting between voltages is done by turning electrical energy into a different kind of energy, and then back.

The first way that came to mind for me when I was young was a motor and a generator connected together. The electricity into the motor becomes turning in the shaft, and then that becomes electricity in the other motor. By adding more or fewer coils to the generator, we can adjust the voltage that comes out, since the voltage from each coil adds together.

I was overcomplicating things, though. See, a motor actually turns electrical energy into magnetic energy, then the magnetism pulls on the shaft. We can skip the middleman and take the shaft out, having the motor’s electromagnets right by the generator’s electromagnets.

That’s all a transformer is. Two sets of coils, one input and one output, right next to eachother. The first coil generates a magnetic field from the electricity, and the second one picks it up turning it back into electricity. By adjusting how many loops is in each coil, we control the voltage that comes out.

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.

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.