Energy from sound

[Hemanth]

Hello every one ........

 

this is my first post and I just wanted to share an idea...

 

can we generate electricity from sound energy...??like making the speaker work in the opposite way....

 

thank you...

[dimreepr]

In my youth I would clamp a pair of headphones to an acoustic guitar and use them as a rudimentary microphone, it can be done but the quality isn’t great. I don’t imagine you’d get very much electricity from this idea even if you seriously scale it up and find a relatively stable source of sound waves.

 

 

[Hemanth]

thank you for you reply.......

may be we can use it in cities where noise pollution is high(at least to light up street light) ..

[swansont]

Sound has surprisingly little energy in it. If you could take all the energy from shouting, with no losses, it would take more than a week to heat up a cup of water for tea or coffee (could be much longer, depending on your assumptions). 80 dB represents only a milliWatt of power.

[Hemanth]

Sound has surprisingly little energy in it. If you could take all the energy from shouting, with no losses, it would take more than a week to heat up a cup of water for tea or coffee (could be much longer, depending on your assumptions). 80 dB represents only a milliWatt of power.

 

OK got it...... ,can we couple this with electromagnetic induction ....? ,because with strong magnetic field even a small movement of diaphragm(in magnetic field) would produce large current ...

please do suggest if there are any other ways to tap out sound energy in an effective way...

[swansont]

OK got it...... ,can we couple this with electromagnetic induction ....? ,because with strong magnetic field even a small movement of diaphragm(in magnetic field) would produce large current ...

please do suggest if there are any other ways to tap out sound energy in an effective way...

 

If you make the field strong then the transducer will be incredibly stiff and you get almost no motion. The problem is simply a lack of energy. You can't extract energy if it's not there in the first place.

[Hemanth]

If you make the field strong then the transducer will be incredibly stiff and you get almost no motion. The problem is simply a lack of energy. You can't extract energy if it's not there in the first place.

 

This what I have understood(please do correct me if I am wrong)...whenever we make magnetic field strong, eddy current induced will also be strong..so it tries to halt the transducer making it stiffer or almost no motion ..but what if we tap out that current as soon as it is generated like in Van de Graaff generator and store it in capacitor....??

Thank you for your reply I was able to refine my idea....

 

 

[ewmon]

Piezoelectric crystals

 

[Bill Angel]

OK got it...... ,can we couple this with electromagnetic induction ....? ,because with strong magnetic field even a small movement of diaphragm(in magnetic field) would produce large current ...

please do suggest if there are any other ways to tap out sound energy in an effective way...

 

Sound is a form of pressure wave. If your area of interest is energy recovery from pressure waves, you might shift your focus from the medium of air to the medium of water. The following link is to an interesting article about capturing energy from ocean waves from either surface waves or from pressure fluctuations below the surface

 

http://ocsenergy.anl.gov/guide/wave/index.cfm

[CaptainPanic]

There exist devices called "thermoacoustic heat engines" and "thermoacoustic heat pumps". Wikipedia has a page about it, although I think it's not the best wikipedia page ever.

 

I bet that the sound inside those devices is a LOT louder than your average street noise though.