Voltages and Turns in a Transformer

[fromthepast]

In a step-up transformer, should the ratio of the voltages be approximately equal to the ratio of the number of turns? Why?

Same for a step-down transformer: should the ratio of the voltages be approximately equal to the ratio of the number of turns? Why?

Thanks

 

[rock.freak667]

For starters how does Faraday's law apply to the transformer in either the primary or secondary side?

 

[fromthepast]

Faraday's law includes the rate of change in magnetic flux through the coil and the number of turns in the coil. I think that the ratio of the secondary emf over the primary emf should equal the ratio of the secondary turns divided by the primary turns; so they should be equal for step-up and step-down. Is my thinking right?

 

[rock.freak667]

Faraday's law includes the rate of change in magnetic flux through the coil and the number of turns in the coil. I think that the ratio of the secondary emf over the primary emf should equal the ratio of the secondary turns divided by the primary turns; so they should be equal for step-up and step-down. Is my thinking right?

Yes they will be the same for any transformer (ideal).

For a step up transformer, the number of turns in the secondary > number of turns in primary so the voltages will change accordingly but the ratios of N_s/N_p will remain the same.

 

[rwisz]

for your question! I can confirm that the ratio of voltages in a transformer should be approximately equal to the ratio of the number of turns. This is known as the turns ratio and is a fundamental principle in transformer design.

In a step-up transformer, the primary coil has fewer turns than the secondary coil, resulting in a lower voltage input and a higher voltage output. This is because the changing magnetic field in the primary coil induces a larger voltage in the secondary coil due to the increased number of turns. The ratio of the voltages is directly proportional to the ratio of the turns, so a higher turns ratio will result in a higher voltage output.

Similarly, in a step-down transformer, the primary coil has more turns than the secondary coil, resulting in a higher voltage input and a lower voltage output. This is due to the same principle of the changing magnetic field inducing a voltage in the secondary coil, but with a lower turns ratio resulting in a lower voltage output.

The reason why the ratio of voltages should be approximately equal to the ratio of turns is because of the conservation of energy. The transformer operates on the principle of electromagnetic induction, where energy is transferred from one circuit to another through a changing magnetic field. The turns ratio ensures that the energy input is equal to the energy output, maintaining the conservation of energy.

In conclusion, the ratio of voltages in a transformer should be approximately equal to the ratio of turns in order to maintain the conservation of energy and achieve the desired voltage output.