amit

I think diaphragm magnet -coil based mics do the conversion just oposite of speakers.....before posting make it a habit of looking for title and post and describe your question briefly.....and get yourself registered.

buy a microphone.

You can also use a speaker. The sound energy vibrates the coil in the magnetic field and thereby deliver a small AC current. The signal must then be amplified. If the sound is looped back into the speaker you may be left with some "free energy".

Please do not expect Fifi sounds.

If a powerful continues source of sound could be found it can theoretically produce some current. Unfortunately not viable.

Alternative get a 2 way radio and put it on VOX, any sound will activate the transmission of 0.5 watt. 120 of these should be enough to operate a 60w globe.

This may contain traces of truth. (but do not place your heart on it)

Your question is somewhat unclear, but I'll do my best to answer.

The conversion of sound (acoustic wave) to current is not very efficient, because the actual energy available in an unfocussed sound wave situation is quite low, and always requires a Transducer to convert the energy form.

There are various ways to obtain current from an acoustic wave, generally done by means of a microphone or similar transducer.

Please note that microphones generally work on the voltage (Volts) change, rather than a current (Amps) change.

Transducer types include:

1. Piezoelectric = Acoustic energy causes compression/depression of a piezoelectric crystal across the mechanical axis, and electrical current may be obtained across the electrical axis of the crystal. (Note: when a piezo crystal stack is suddenly and firmly struck on the mechanical axis, generating a high voltage - the piezo gas lighter)

2a. Dynamic = A diaphragm vibrated by an acoustic wave is mechanically connected to a magnet, which is generally inside an insulated wire coil - A voltage is generated because of the magnetic lines of force being cut.

2b. Dynamic = As above, with a moving coil inside or outside a fixed magnet = same result.

3. Electrostatic = Parallel Plates energised with High Voltage DC,when the distance between them is altered by an acoustic wave, a small voltage is generated.

4. Condenser (Capacitor type) = As for (3) above, but the applied DC voltage is low,generally from a small dry cell battery.

5. Electret (Capacitor type) = Same as (4) above, but no battery is required, because during manufacture a permanent charge is inbuilt into an insulating compound.

If a high-powered low frequency audio wave is available, in a fluid medium such as a lake or the sea, then other methods for obtaining useful power are available:

A large diaphragm, mechanically connected to a compressor via a one-way valve,this will allow a pumping action, and that in turn could run an alternator or dynamo.

There are other ways, and if you think about it, you may discover more.

If I have misunderstood your question, please clarify, and advise in this Topic Thread, thank you.