# Inductive coupling with/and AC?

Several things I wanted to know, but couldn't find;

If 2 AC outputs are of the same amplitude, but of different frequency, will one necessarily be higher in power?

In a conventional transformer, (not resonant) does a higher frequency allow for higher efficiency coupling? Does this change if the transformer is resonant?

Is a 'standard' transformer more efficient than a resonant one at a very close range? (Provided that frequency, power, etc. are all the same?)

And lastly, does the resonant frequency of a resonant inductive coupling circuit affect the frequency at which it couples?

(did that all make sense?)

Thanks

## Discussions

Best Answer 10 years ago

1.) No.

2.) No.

3.) clarify

4.) Yes, of course, you couple AT the resonant frequency. The ACT of coupling reduces the resonant peak.

You don't define "resonant transformer " in this context.

Answer 10 years ago

Resonant trasnsformer as in 2 resonant coils (same freq.) Does q factor go up with frequency or something? And if the load is too high, it's gonna throw the secondary off, right, but if it's too low, it'll not take all the energy transfered...

Answer 10 years ago

. OK. It's been a long time since I studied AC circuits and almost as long since I used what I learned, but, for #1, if the amplitude is the same, won't the RMS voltage and power go up with frequency? Enquiring minds want to know.

Answer 10 years ago

Nope, RMS voltage is independent of frequency, and voltage is NOT THE SAME AS power - the source impedance isn't specified, if it was infinite, whatever voltage you see, you can't draw current, so you've no power.

Answer 10 years ago

. I should know better than to trust my memory at my age.

> voltage is NOT THE SAME AS power

. I understand that, but if the load remains the same and you increase the voltage, don't current (I=E/R) and power (P=E²/R) go up also?

Answer 10 years ago

If the load remains the same, but load wasn't mentioned was it ?

Answer 10 years ago

You didn't answer his fifth question.

Answer 10 years ago

Wow! I couldn't even come close to answering this one. I only got one of four right.

Answer 10 years ago

I might be being pissy with definitions though I think I am strictly right.

Answer 10 years ago

It all starts with a proper definition.