Can we obtain electrical energy from sound signals?

Click For Summary

Discussion Overview

The discussion revolves around the feasibility of converting sound signals into electrical energy, specifically exploring methods or devices that could efficiently harness sound energy to power small electronics like LEDs or buzzers. The conversation touches on theoretical and practical aspects of energy conversion from sound, including the use of piezoelectric speakers and the challenges associated with energy harvesting from ambient noise.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant inquires about methods to convert sound signals into electrical energy efficiently enough to power devices like LEDs or buzzers.
  • Another participant suggests that while sound waves have kinetic energy, the amount generated from typical sound sources, such as a human voice, is insufficient for practical energy generation, and emphasizes the need for high-power sound sources.
  • Concerns are raised about the efficiency of using piezoelectric speakers to capture energy from sound, with a suggestion that it may be more effective to directly power devices rather than attempting to harvest energy from sound waves.
  • A participant questions the potential of using high-frequency noise signals from the environment to generate electrical energy without external power, indicating a curiosity about ambient noise as a resource.
  • Another reply highlights the limitations of sound energy harvesting, noting that sound energy is often too weak to be effectively captured by typical collectors, and compares it to the energy available from light sources.
  • One participant mentions the concept of vibration energy scavenging in high-vibration environments, suggesting that while small amounts of energy can be harvested, it may not be sufficient for powering devices like LEDs or buzzers without significant energy storage and efficiency considerations.
  • A link is provided to additional ideas, reiterating that even at high sound levels, the energy that can be harvested is minimal, countering the perception that there is abundant acoustic power available.

Areas of Agreement / Disagreement

Participants express a range of views regarding the potential for sound energy conversion, with no consensus on the feasibility of effectively harnessing sound signals for significant electrical energy generation. The discussion remains unresolved, with various perspectives on the limitations and possibilities of sound energy harvesting.

Contextual Notes

Participants note the dependence on sound source power levels and the challenges of capturing sufficient energy from typical sound waves. The discussion also highlights the need for high efficiency in circuitry to make sound energy harvesting viable.

imnitsy
Messages
11
Reaction score
0
can we obtain electrical energy from sound signals??

hello everyone..

i want to know that is there ny method or any apparatus to convert the sound signals into electrical energy efficiently such that it will glow a led or can acticate a buzzer!

well i know about sound detector circuits that detects sounds with the help of the condenser mic but the source of electric energy in them is the power supplied to the amplifier circuit..

what i want to know is that can we convert the sound signals like our voice to some remarkable amount of electrical energy ??

regards
imnitsy
 
Engineering news on Phys.org


Interesting concept, but unfortunately this experiment has been reproduced regularly by amatures. I suggest searching for videos on youtube

The following video is rather pitiful, because his method of applying energy to the piezoelectric speaker was by his hands and needless to say, more kinetic energy is transferred by pushing something than by letting typical sound waves harmlessly bumping against it.
http://www.youtube.com/watch?v=s3Ftl6n9Oq0"
To make electricity, the piezoelectric speaker must vibrate. Additionally, sound waves do indeed have kinetic energy but one would have to have a heck of a speaker to generate the sound waves required to register any useful current from the piezoelectric speaker. Let me remind you that you wanted to use someone's voice opposed to the largest loud speaker in the world.
Also, the voltage applied to a piezoelectric speaker is very high compared to the current that is being applied. You need voltage and current to make a viable power source.
Remember, using a speaker to generate sound waves and then using a series of piezoelectric speakers to recapture that energy is only making a ridiculous amount of noise and waisting electricity. It would be more efficient to hook the power to the speaker directly to a long series of LEDs.
There simply isn't enough energy in the typical sound wave to generate "some remarkable amount of electrical energy" but perhaps enough energy could be generated to run nano-electronic devices where the power needed is much much lower.

Your idea is novel, keep thinking!
Remember, one learns more from their failures than from their successes.

Regards,
-Tay
 
Last edited by a moderator:


well i have one more doubt about it..
what happen if we provide the peizoelectric speaker with high frequency noise signals ?

as in our surrounding we have a lot of disturbances caused by various types of noise!

is there any way of utilising these noise signals to produce electrical energy without using any external power source ??
 


imnitsy said:
well i have one more doubt about it..
what happen if we provide the peizoelectric speaker with high frequency noise signals ?

as in our surrounding we have a lot of disturbances caused by various types of noise!

is there any way of utilising these noise signals to produce electrical energy without using any external power source ??

You hear lots of noise, but your ears are very sensitive sound sensors. There just isn't much sound energy around for a reasonably sized collector to harvest. Notice that the output of a microphone usually has to be amplified, the weak signal being used to generate a more powerful signal using electrical power from another source, before it's of any use.

Think of a 100 watt light bulb. Right next to the bulb, it's bright and hot, you can trap a good portion of that 100 watts with your hand. Across the room, you're lucky if you can operate a small calculator. Sound waves spread out too, and there are very few sound sources comparable in emitted power to the visible and infrared light emitted by that light bulb.

I have seen vibration energy scavenging used to power small wireless sensors, but this was in the context of high-vibration machine environments, and for that sort of application you can get by with less than a milliwatt of average power, storing up energy and releasing it in bursts if necessary. There's also things like self-winding watches that use the motion of the wearer as their power source. You're not going to get much more than that...even flashing an LED or sounding a buzzer will take very high efficiency circuitry and a considerable period of storing up enough energy first. Look up "energy harvesting", and "solar engine" for something similar using small solar cells.
 


This link includes some ideas.
https://www.physicsforums.com/showthread.php?t=338283
The bottom line is that, even in sound levels corresponding to the threshold of pain, you couldn't knock the skin off a rice pudding with the power you could harvest. Your ears are very very sensitive and give you the impression that there are vast amounts of acoustic power around. In fact, there aren't.
 

Similar threads

Replies
7
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
11
Views
2K
  • · Replies 12 ·
Replies
12
Views
2K
Replies
66
Views
10K
Replies
4
Views
3K
Replies
14
Views
10K
Replies
20
Views
6K
Replies
10
Views
3K