Yes, I had looked into the operation of a supercapacitor during the course of this research. I do admit that it may be a game changer, but I also see a possibility in producing voltage using the regular electrolytic capacitors. As for the dynamic microphone, I haven't seen a suitable way to combine it with a model circuit. Thanks for your response in anticipation.

Your circuit requires external power. You will not be generating power you will be consuming it with the microphone regulating the amount you use.

 

The foundational theory for this is sound is a form of mechanical wave and when harnessed properly can produce electricity as per Faraday's law of electromagnetic induction. The science is undisputed and this is what I am trying to thrive on by trying actually doing it practically. I just haven't been able to make it work yet. Do you agree with the science?

Yes, but I also agree with the second law of thermodynamics.
From post #13, in an average size room of 5x3x3m, with a SPL of 50dB, The total surface area 78m^2, the energy available would be 100nW/m^2. If you can harvest ALL the sound you'd get 7.8uW, and it would be very difficult to talk - every tried to talk to someone in an anechoic chamber?
With the present efficiency of microphones, you'd get far more power with a current transformer around the speaker leads!
And if you were thinking of harvesting energy from sound that was produced by an amplifier and loudspeaker, it would be more efficient to use a plug-in power supply, because the amplifier would be 78% efficient, the speaker would be about 1% efficient, and a plug in power supply would be about 85% efficient.

 

A piezo transducer generates a small voltage at a very small current when it is flexed slightly.
Somebody mounted hundreds of piezo transducers on a busy sidewalk and made enough electricity to dimly light one little LED.

Yes, I am familiar with the principle of a piezoelectric in the sense of squeezing crystals to produce electricity. The foundational theory/science is that sound is a form of mechanical wave and, as per Faraday's Law of electromagnetic induction, should be able to produce electricity. This is all I am trying to validate by doing it practically. The sound sensor module in the arduino kit prod=uces small voltage with range of 0-3.2v. The purpose of the module is definitely not to generate voltage but in some sense speaks to what I am trying to achieve. I just need help in getting a reliable circuit that would produce voltage no matter how small. The circuits can be multiplied and the voltages summed up using an adder amplifier. Thanks for your response in anticipation.

 

Your circuit requires external power. You will not be generating power you will be consuming it with the microphone regulating the amount you use.

Not exactly really. The circuit, like any circuit, would require power to operate. But if the mic functions properly as an input signal, the circuit can become self sustaining. In the sense of a feedback loop (sort of).

 

An electret microphone is a sort of variable capacitor which must be externally powered. A diaphragm inside moves when sound waves hits it, varying the capacitance. A circuit is used to convert that change to a varying voltage which is an analog to the sound. The power doesn't come from the sound, it comes from the poser supply for the circuit.

A dynamic microphone had a permanent magnet. A coil is attached to a diaphragm with is mounted so that the coil is free to move around the magnet. Sound moved the diaphragm, and the coil moves generating electric current because of the magnetic field cutting across the conductor in the coil—it is a small generator. It is very much like a permanent magnet speaker optimized to receive rather than transmit sound.

The current involved is exceedingly small. Collecting it is a serious challenge. Losses and threshold voltages make is nearly impossible without additionally powered circuity, which confounds your goal.

 

Not exactly really. The circuit, like any circuit, would require power to operate. But if the mic functions properly as an input signal, the circuit can become self sustaining. In the sense of a feedback loop (sort of).

This is entirely wrong. The external power is regulated by the microphone. Its signal is not powering anything, it's being used to decide how much of the power supply should appear at the output.

It can never produce enough power to operate the circuit.

 

The foundational theory for this is sound is a form of mechanical wave and when harnessed properly can produce electricity as per Faraday's law of electromagnetic induction. The science is undisputed and this is what I am trying to thrive on by trying it practically. I just haven't been able to make it work yet. Do you agree with the science?

Just another point. If you want to confirm Faraday's law, an electret microphone has nothing to do with it and a dynamic microphone already shows it without charging a battery. The microphone produces an electrical current which can be measured and can be amplified so the sound can be reproduced.

Charging a battery adds nothing.

Why do you feel the need to do that part?

 

Yes, I am familiar with the principle of a piezoelectric in the sense of squeezing crystals to produce electricity. The foundational theory/science is that sound is a form of mechanical wave and, as per Faraday's Law of electromagnetic induction, should be able to produce electricity. This is all I am trying to validate by doing it practically. The sound sensor module in the arduino kit prod=uces small voltage with range of 0-3.2v. The purpose of the module is definitely not to generate voltage but in some sense speaks to what I am trying to achieve. I just need help in getting a reliable circuit that would produce voltage no matter how small. The circuits can be multiplied and the voltages summed up using an adder amplifier. Thanks for your response in anticipation.

An electret microphone is a sort of variable capacitor which must be externally powered. A diaphragm inside moves when sound waves hits it, varying the capacitance. A circuit is used to convert that change to a varying voltage which is an analog to the sound. The power doesn't come from the sound, it comes from the poser supply for the circuit.

A dynamic microphone had a permanent magnet. A coil is attached to a diaphragm with is mounted so that the coil is free to move around the magnet. Sound moved the diaphragm, and the coil moves generating electric current because of the magnetic field cutting across the conductor in the coil—it is a small generator. It is very much like a permanent magnet speaker optimized to receive rather than transmit sound.

The current involved is exceedingly small. Collecting it is a serious challenge. Losses and threshold voltages make is nearly impossible without additionally powered circuity, which confounds your goal.

This is a very intelligent argument. From your standpoint, do you believe sound can be converted to electricity? And if yes, how do you propose?

 

Just another point. If you want to confirm Faraday's law, an electret microphone has nothing to do with it and a dynamic microphone already shows it without charging a battery. The microphone produces an electrical current which can be measured and can be amplified so the sound can be reproduced.

Charging a battery adds nothing.

Why do you feel the need to do that part?

Doesn't the condenser microphone (electret) also produce Mic-level electrical signals?

 

This is a very intelligent argument. From your standpoint, do you believe sound can be converted to electricity? And if yes, how do you propose?

A dynamic microphone already does this, you just can't charge a battery with it which is not a necessary attribute for something that converts sound to electrical energy.

That you can measure the output of the microphone and it is proportional to the sound shows that electricity is being generated by the movement of a coil in a magnetic field caused by acoustical energy.

If that's what you want to show, connect a dynamic microphone to an oscilloscope or and amplifier with a speaker. Each demonstrates the effect in its way.

 

Doesn't the condenser microphone (electret) also produce Mic-level electrical signals?

No, an electret microphone regulates the flow of an external power supply which is why they need to be powered.

An analogy (don't extend it very far) is the difference between a dynamo and a switch. If I have a hand cranked generator I can convert my arm motion to electricity. If I have a switch connected to a power supply, I can use my arm motion to switch it on and off but I will never be generating anything even if I could. The mechanical motion in this case is not being used to generate anything, only to control it.

 

Doesn't the condenser microphone (electret) also produce Mic-level electrical signals?

As an example the AKG C451 capsule produces a signal of about 10mV into a load impedance (the input impedance of the preamp) of 1GΩ. Output power = 100fW

 

A dynamic microphone already does this, you just can't charge a battery with it which is not a necessary attribute for something that converts sound to electrical energy.

That you can measure the output of the microphone and it is proportional to the sound shows that electricity is being generated by the movement of a coil in a magnetic field caused by acoustical energy.

If that's what you want to show, connect a dynamic microphone to an oscilloscope or and amplifier with a speaker. Each demonstrates the effect in its way.

Sound is a ubiquitous part of the world. Harvesting sound to generate electricity can only take us a step forward in supplying sufficient energy. All I am trying to do is show this possibility on a small scale. It is actually a research project but it is more than that to me. It is beyond the grades... I deeply believe something can be done in this sector. I have read multiple papers on this and tried to reach out to some of the authors with very little responses. Any advice on how to do this will be deeply appreciated, thanks Yaakov. Your responses mean a lot.

 

Most naturally occurring sounds are due to air or water movement over surfaces. We already have well developed technology to convert air and water movement into electricity.

 

Sound is a ubiquitous part of the world. Harvesting sound to generate electricity can only take us a step forward in supplying sufficient energy. All I am trying to do is show this possibility on a small scale. It is actually a research project but it is more than to me. It is beyond the grades... I deeply believe something can be done in this sector. I have read multiple papers on this and tried to reach out to some of the authors with very little responses. Any advice on how to do this will be deeply appreciated, thanks Yaakov. Your responses mean a lot.

Energy harvesting is an important area of research but it’s not free energy. Everything to do with energy has a cost. There is a lot of sound but in any given area there is very little energy from it. The thermodynamics do not make sound as an energy source useful.

I am sure you are very sincere in your conviction that there is something useful here, but you are wrong. With absolutely no insult intended you are suffering from the Dunning-Kruger effect. It gets all of us, it’s part of being human.

I would suggest you investigate thermodynamics first so you have an idea of how the whole energy ledger balances out. The world is very good at making things balance and almost never is there some sort of secret surplus we just have to “tap into”. The laws of thermodynamics are tyrannical. Get familiar with them, they will help you see where real opportunities lie.

I don’t want to discourage you from looking for new things, far from it, but you need to know which of the infinite directions you can look have real promise.

 

To use light as an analogy:
If you were to harvest energy from the light in a room using solar cells
Solar cells are black, rooms are generally painted pale colours which reflect light.
The more solar cells are used, the darker the room becomes, and it's necessary to use more artificial light.
What have you gained?

 

People like you are rare - Intelligent and humble. Thanks for all your help, Yaakov. I do believe there is tremendous potential here and the science proves it. Its not energy from empty space or vaccum... for sound to be generated, a force must be in play. Sound is the vibration of air molecules that receed from the source. The microphones aren't produced to function in this way and maybe that's why it may be difficult for many to realize its possibility. Sound is very volatile which is an obvious deterent. But like you said, the universe has its way of balancing things out; in this case, I believe it is in the availability.

 

To use light as an analogy:
If you were to harvest energy from the light in a room using solar cells
Solar cells are black, rooms are generally painted pale colours which reflect light.
The more solar cells are used, the darker the room becomes, and it's necessary to use more artificial light.
What have you gained?

I believe the difference here is having multiple acoustic converters in a room isn't the scope. However, if we are to inspect this, consider a room with a family watching a tv show at moderate volume. Placing the acoustic converter beside the television doesn't dim the volume, neither does it make the show less enjoyable.

 

I believe the difference here is having multiple acoustic converters in a room isn't the scope. However, if we are to inspect this, consider a room with a family watching a tv show at moderate volume. Placing the acoustic converter beside the television doesn't dim the volume, neither does it make the show less enjoyable.

Yes it does reduce the volume if it does any work, like converting the mechanical energy to something else (e.g. heat, electricity, &c). YOu can’t double dip. Whatever portion of the sound‘s energy is used to make electricity is no Longer available to move the parts of the ears of the watcher that transduce the sound’s energy into the perception of sound.

TANSTAAFL

 

I believe the difference here is having multiple acoustic converters in a room isn't the scope. However, if we are to inspect this, consider a room with a family watching a tv show at moderate volume. Placing the acoustic converter beside the television doesn't dim the volume, neither does it make the show less enjoyable.

So let's say you are listening at about 60dbA. The energy in that sound would be about 1uW/m^2. If you harvested half that energy, say 500nW/m^2 and made it 57dBA in the room. With a hypothetical 100%-efficient transducer a metre square you have half a microwatt.

The speaker would have an efficiency of around 85dB@1W@1m, so an amplifier in the television would require 3mW to produce your half a microwatt.

The total efficiency in the system would be a thousand times better if you obtained the power directly from the mains.