Sound To Electricity

[FreeEnergy]

what about this?

[exnihiloest]

...
http://www.google.com/patents/about?id=Gs6SAAAAEBAJ
...

Rather strange: the inventor is expecting to charge a battery with AC, he forgot the diode between the microphone and the battery. And why the ground connection?
With a diode the principle should work in theory, but the level from the microphone is surely less than the diode threshold (except on an airport runway ).
Do I miss something?

[sm0ky2]

Hi Smoky,

The circuit looks off too me, there would be leakage current through the speaker to ground. I would place a germanium diode between the receptor and cap.

A array of these in a parabolic dish pointed at a busy airport, highway or a waterfall would generate some power.

i've always been interested in converting sound energy into electricity.. theres so much ambient sound in our man-made environment (and some natural environments too). 

what about utilizing a cavern/echo effect? would that create then, more sound energy for the reciever to pick up, from any given source?

we need to build a VERY large microphone.. like the size of a 12" speaker.

something that can create a great deal of coil-movement from the sound source.

i guess i was looking at the battery as being backwards in the patent circuit. i think the "leakage" current is intentional.

since the microphone generates electricity in both directions, going inwards it would charge the cap, then immediately discharge the cap as the microphone moved outwards, push it stronger than the sound waves did on the way in (double minus losses?), its almost like a self-rectifying circuit.......

[DreamThinkBuild]

Hi All,

I built this circuit both ways with and without the diode.

I used a 10uf Electrolytic cap to represent the battery(I'll call it C2), that way I could discharge it to zero.

I used a 2nf cap as C1

Okay the first problem I ran into was all my speakers I tried could not generate enough power with the original design. I went and used my piezo speaker which worked good. Puts out about 40v-50v spikes when slammed.

Now without the diode and the scope probes(20mv div setting) across C2 in DC mode, when I hit the piezospeaker it would quickly jump in voltage maybe about 5-7mv but it would quickly drop down below the baseline(10mv). No matter how many times I hit the speaker it would not gain a charge. This confirms there is leakage current through the speaker.

Okay now for the odd part, I placed a Germanium diode(1N60) between the speaker and C1 and slammed again C2 did go up but slowly dropped back down. Maybe faulty(?), I have to go scavenge another one and try again later. I tried a regular diode a 1N4148 and C2 started to charge on each slam getting up to only 100mv before I stopped.

Redesigning the circuit I removed C1 and placed the diode between receptor and C2. Doing this gave full power from the piezo speaker to C2. Just blowing hard across the piezospeaker would raise C2 a couple millivots. Slamming it would raise C2 500 to 700 millivolts. Several slams and C2 was up over a volt. Removing C1 also allowed my speaker and microphone to start charging C2 a little slower than the piezospeaker. A larger speaker should work better as Smoky suggested.

I'll have to do some more tests with this. It is such a simple circuit, yet it's charging the cap. What I find interesting is unlike a antenna based cap charger, which is linear charging over time, the voltage in the cap will raise quickly with loud noises(non linear).

If you want to try this just replace C1 with a diode and the battery with a large cap or ultracap. If you find any other ways to improve this circuit share it here.

Hi Smoky,

I like the idea of using the echo from a cave.

[sm0ky2]

@ Dream

thanks for the results of your work. great job.

i would like to try this with a [edit] Microphone-type device designed to collect sound. while a speaker should in theory "work"... it is engineered to create sound. (reverse of what we're wanting to do here). and so i do not think it can harness the full power of an incomming wave.

that being said, i will dismantle a mic  and perform similar experiments. soon as i replace my meter ( testatika conversion gone bad...).