Happy New Year everyone.
My primary interest in whats happening on Fieldlines is to have a better understanding of motors,coils,generators,magnets and how they all work...
...my goal is to build a micro 5-way electronic compressed air actuator that I can use in conjunction Lego Mindstorms and Lego Pneumatics to control air powered devices on my Lego robot J5 (see. http://www.stop4stuff.com/lego/technic/mindstorms/new-j5/ for a build diary.)
Whilst browsing threads and absorbing input...
No-one seems to be discussing the extraction of electrical energy from sound.
...a microphone generates electricity.
Also I have read and understood the reasoning why linear alternators are inefficient...
...isn't a microphone a linear alternator?
speculation over with... try this...
1. obtain a car stereo speaker, the bigger the better.
2. attach an LED across the speaker terminals.
3. gently, but quickly tap the speaker cone
you should see the LED flash intermitantly (if it doesn't, swap the LED connections over)
Tapping on a steel coffee tin placed open end over the speaker also makes the LED light up.
I haven't a clue what voltages or currents are involved... but the LED lights up.
Sound can be focused, in the same manner as sunlight, onto the collector by means of reflectors... like the old fashioned 'ear trumpets' often seen in old black & white slapstick comedies (Charlie Chaplin, Laurel & Hardy, etc).
Nature can produce devices that mix sounds to a level of white noise... listen to a sea shell!
the 'ear trumpet' is a spun shape, a large inverted cone with a smaller inner inverted cone.
I understand a little about electronics, however I think that there would be a whole load of different frequency sounds (and ac voltage frequencies generated)...
...could the sound coming in be split by physical filters to seperate different frequency sound before it got to the collectors (microphones), or be used to create powerful harmonic frequencies?
...could the different frequency voltages be collected seperately and then converted to an average frequency before final smoothing out and frequency reduction?
Why could electricity generated from sound be useful?
...wind generators are good for sparsely populated areas... more space to put them up.
...the noisiest places are often places where it would be impossible to put up a wind generator.
and no I've not forgotton about solar power...
could the underside of a motorway (freeway) bridge be covered with solar panels?
Generating electricity from sound could be an addition to other green energy solutions, who know's maybe one day we'll have fence panels that provide power to white LED street lighting.
About transformers and sound...
a transformer hums...
it makes a noise...
Can it be vibraition that makes a transformer hum?
...a transformer has no moving parts to create the intertia to make it vibrate!
...so why does a transformer put out noise energy?
The trick with a sheet of aluminium and a neo magnet is cool... even near vertical the magnet creeps down the ali sheet.
sorry to go on.... first timer poster... fresh with enthusiam :)
p.s. love the hamster powered alternator on theotherpower.com... we tried something similar with Angel (my daughter's Syrian hamster) in a ball running on a Lego setup... friction vs hamster... friction won
