Finding efficiency between transformers.

[Crusaderking1]

Ok, I have a primary and secondary coil. I set up a transformer between them. Each has 400 turns of coil(N). The primary coil produces a potential difference of 2.988 V. The secondary coil has a potential difference of 0.0551 V.

For the efficiency, I used the equation (Np*Vs)/(Ns*Vp) * 100%

Np-turns of primary coil(400)
Vs- potential difference of secondary coil(0.0551)
Ns- turns of secondary coil(400)
Vp-potential difference of primary coil(2.988)

When I plug them in, I get 1.84% efficiency.

Am I messing the formula up, plugging in the wrong values. etc?
1.84% seems awfully low.
Thanks.

 

[Redbelly98]

For equal number of turns on the primary and secondary, a 100% efficient transformer would have equal voltages on the primary and secondary. But the problem statement does give an awfully low value for the secondary voltage, namely 1.84% of the primary voltage.

Perhaps if you can you post the question in its exact wording, I can see if there is something we are missing.

 

[Crusaderking1]

This was a lab experiment, and these values were measured or given. the two coils were set up with an iron core and were faced toward each other with 2 voltage probes acting as a voltmeter.

Later on for a separate trial, we had the iron core placed right through the transformer with still two 400 coils, and then I calculated a reasonable 60.4% efficiency using the same formula as earlier.

I'm guessing that its a possibility that the more O-shaped iron core involved, the more efficient the transformer was, and that having no O-shaped iron core made it extremely, yet unbelievably, inefficient.

 

[Redbelly98]

Okay, it makes more sense now. Without the iron core in place, the coils are not coupled as strongly to one another.

 

[asteriatic]

I would first like to commend you for setting up a transformer and calculating its efficiency. It shows a good understanding of the principles involved. However, it seems like there may be some mistakes in your calculations.

The formula you used, (Np*Vs)/(Ns*Vp) * 100%, is correct for calculating the efficiency of a transformer. However, in your case, you should be using the turns ratio (Ns/Np) instead of the number of turns in the formula. This is because the turns ratio is a measure of the relative number of turns in the primary and secondary coils, which affects the voltage difference between them.

So, the correct formula for efficiency in your case would be (Vs/Vp) * 100%, which gives an efficiency of 1.84%. This is a very low efficiency and could be due to various factors such as resistance in the coils, magnetic losses, and other losses in the transformer.

To improve the efficiency of your transformer, you could try using a different core material with lower losses, increasing the number of turns in the secondary coil, or using a higher frequency for the input power. These are just a few suggestions, and there may be other ways to improve efficiency based on your specific setup.

I hope this helps clarify any confusion and encourages you to continue exploring and experimenting with transformers. As a scientist, it is important to always question and analyze our results to strive for better understanding and improvement. Keep up the good work!