Use of sound energy in mobile

Replies

• 

  Anil Jain

  I never thought of it. Just amazing thinking !!!
  
  Its kinda similar to the reusabilty of energy in cars - where we can use lapsed energy (Energy generated because of breaking) as a fuel.
  
  Electronics/Telcom guyz any crazy idea on this??
  
  -CB
• 

  Ashraf HZ

  No, this wont work efficiently unfortunately. The sound energy from our voice is very low actually, thats why amplifiers in the phone are used to increase it to usable levels. This amplification requires power 😉
  
  In fact, the sounds we hear in everyday life, propagating through pressure waves, seems powerful... but in reality, its our ears that amplify the sounds.. and only specific sounds at that. Sounds that could be useful to tap are probably shock waves from thunders.
  
  Two avenues which I think work better are either solar cells, or using dynamo/alternators. We are having discussions here on CE on the latter to put into use in sewing machines.. maybe that can be applied to mobiles?
• 

  silverscorpion

  Yep.
  
  As Ash said, it's very difficult to use our sound energy to recharge our
  phones.
  We may think of using piezoelectric crystals. But the sound from our speaking
  does not produce enough energy to vibrate the crystal. So, as attractive the
  idea looks, it's currently not feasible.
  
  May be, if we can somehow produce some ultra sensitive crystal that'll vibrate
  with this small amount of energy, then we can think of recharging while we
  speak.😛
• 

  silverscorpion

  A more feasible idea would be to incorporate such crystals in the keypad of the cell phone, so that, while we press the buttons, the phone gets charged.
  This will be really useful, since we usually send a lot of SMS's. And even if not, we can charge the phone on the go by simply pressing some buttons randomly. Very handy in emergencies.
• 

  Ashraf HZ

  Nice..the piezo keys is an interesting idea.. even if it cannot really charge the phone while in use (since you'll need to output more power than its consumption), it could extend battery life.
  
  For charging the phone, I still think a compact alternator would work better for emergencies, like with a mechanism like those wind-up pencil sharpeners. This has worked successfully for radios, and there are some dynamo/alternator products out there that are used to charge phones. Perhaps we can think of one that can be embedded on the phone itself. We can incorporate SS's piezo idea too.
  
  .. I smell a potential CE project in the works! (before you shoot me shalini, I stress potential.. 😉 )
• 

  silverscorpion

  Yeah, I've heard about those manual mobile chargers too. Would be interesting to do it ourselves..
• 

  swapnakumar

  sound signals are low in frequency and amplidtude i dont think they can recharge our mobiles this sounds too imaginative
• 

  shalini_goel14

  If I am not wrong and the objective of this thread is to use "Sound Energy" in mobile then it means someone will have to talk even when don't want to - also resulting in considerable increase in phone balance hmmm? 😒
  
  Also as per few of our CE electronics/Telecom people - the human sound is actuall of low frequency . So ashutoshglamour, I guess this idea wouldn't work much.
  
  PS:Feel free to correct me if wrong. 😀
• 

  ashutoshglamour

  shalini_goel14

  If I am not wrong and the objective of this thread is to use "Sound Energy" in mobile then it means someone will have to talk even when don't want to - also resulting in considerable increase in phone balance hmmm? 😒
  
  Also as per few of our CE electronics/Telecom people - the human sound is actuall of low frequency . So ashutoshglamour, I guess this idea wouldn't work much.
  
  PS:Feel free to correct me if wrong. 😀

  ya i know its too imaginative but donot say impossible.
  science is interesting only when one converts impossible into possible.
• 

  anilalur

  Not feasible with piezo. May be some supercaps can help. But the cheapest will be some kinda manual solution or even a PV panel.
• 

  shalini_goel14

  ashutoshglamour

  ya i know its too imaginative but donot say impossible.
  science is interesting only when one converts impossible into possible.

  Good spirit man. Liked it but I never said it is impossible.😀 Thing is about its feasibility.If you want to use sound energy - why not use all noise -pollution causing sources.
• 

  Ashraf HZ

  Warning.. a slightly long post 😉
  
  

  ashutoshglamour

  ya i know its too imaginative but donot say impossible.
  science is interesting only when one converts impossible into possible.

  Right on, my friend 😀 It'll truly be a waste if we do neglect this possibility.
  
  Alright, I suppose we could just focus on trying to utilize sound energy in this thread and move other ideas (P.V, manual, tactile piezo keys, etc) in separate threads. We could eventually augment the different ideas later on.
  
  We have established that the human speech may not be sufficient to charge while it is on. We can perhaps use it while its off, but there is no motivation behind talking into a dead phone for hours. In terms of modeling the "energy" of the human speech.. its most likely that the gain factor of its amplitude is used more, rather than the frequency.. since it's bandwidth is only between 50 Hz - 400 Hz.
  
  Just a little trivia:
  Male: 50 Hz - 200 Hz
  Female: 150 Hz -300 Hz
  Children: 200 Hz- 400 Hz
  
  Notice the overlap between male and female speakers 😉 Increasing the frequency would not damage our ears as long as the amplitude is within safe levels. But once you increase the amplitude (i.e. volume) up a few dB's, there is an increase of pressure of the sound waves. Of course.. short of screaming into the phone, the max amplitude of a speech is still not sufficient enough.
  
  We should approach our idea around Shalini's comment about sounds in general.. or more so, noise pollution. Buses passing by, cars honking, an annoying neighbour blasting rocks songs. These are high amplitude signals that we could possible capture.
  
  In addition, there are still a lot of noise that we cannot hear since its beyond the human hearing's threshold, things like ultrasonic as well as infrasounds.. so it would be interesting to see what we can do with these sounds. Infrasounds, those that are very low in frequency, may be useful when the phone is set on the table or floor. Vibrations in the ground itself are infrasonic sounds, and sometimes with a sufficient amplitude to be useful. The most extreme case of infrasonic sounds being of high energy would be an earthquake 😉
  
  We had a discussion on CE about using "sound" from the exhaust of a motorbike. We've arrived at the same conclusion about the sound we hear being not useful enough, but at the same time, the vibrations itself can be used since its of higher amplitude.
  
  I guess piezo crystals are worth a second look. Since we want it to work passively, it would be wiser to try "channeling" the soundwaves into it for it to work more effectively.. just like horn or cone antennas.
  
  I'm hoping some sound engineers can chip in with their ideas. I know we had at least one on CE last time 😉