[Dino Segovis] wrote in to share yet another installment of his Hack a Week series, though this one is quite timely.
It was 131 years ago today that [Alexander Graham Bell] unveiled the Photophone to the world. A precursor to fiber optic technology, [Bell’s] incredibly important invention can be easily replicated in your garage, as [Dino] shows us.
The original Photophone was constructed using a megaphone and crystalline selenium cells at the focal point of the receiver, however this version can be made with easy to obtain parts. [Dino] rigged his laptop up to a speaker on which he mounted a mirror, before setting it out in the sun. The vibrations of the mirror modulate the sunlight, reflecting it onto a solar cell positioned at the end of a long, black PVC tube. The solar cell’s leads are fed into an amplifier followed by a speaker, which broadcasts the audio.
The demonstration goes off without a hitch, and while some might be underwhelmed by the technolgy, imagine how incredible it would have looked 131 years ago!
Who knew solar cells could respond that fast…
pretty cool
What an outstanding hack. Can’t wait to do this with my kids.
The seriously amazing part is this is from 130 years ago…
Underwhelmed?! It still never ceases to amaze me just how amazing some of this stuff is. We live in the future.
I remember first learning about this technique from the outstanding Forrest Mims guides a good 15 or more years ago. Very nice.
Bell tried to get glass fiber put up instead of wires but people thought the old man had snapped.
Nice.
What always gets me is the ‘nominative determinism’ of Alexeander Graham Bell:
http://en.wikipedia.org/wiki/Nominative_determinism
He didn’t invent the Bell
I know lots of people with the surname Bell and none of them invented anything Bell related
Maybe its just a coincidence?
yep thought so get over it
@pff – “I know lots of lots of people with the surname Bell and none of them invented anything Bell related”…
Are you wearing a lab-coat and occasionally consulting notes on a clipboard whilst speaking in a flat Germanic monotone?
Graham Bell was way way way way way ahead of his time, I wonder what he would be inventing if he was alive today?
I don’t think i understand your comment
was it a lampoon?
Skype for Android (but with video)
Well, you diss me, I kick back! – Simples : )
(My riposte was an allusion to the film cliche of the Logic-Driven Nazi Scientist who knows everything except humanity, kindness & humour – Yep – a bit extreme – din really mean it at all – jus kidding – all the best to you now!)
Dude using this principal and a laser can i use it for beaming internet?
Champion effort!
Cheers.
ir-diodes can do the same thing
^@Morbious Stone:
http://www.freespaceoptics.org/
Hey thanks Hitek146 so awesome!!
For a more direct read:
http://www.google.com/search?tbm=pts&tbo=1&hl=en&q=Photophone+bell&btnG=Search+Patents
= Google patent search for ‘photophone’ and ‘bell’
(I find it more reliable and informative to actually see a patent rather than hear someone who heard someone tell about it.)
A search results page is more direct? :)
@Dino Yes, it shows relevant patent but there are a bunch of those and with various dates and on various aspects of the concept, so a single link to a single patent would not do.
And besides, it’s google that provides the patent reading interface so it’s google anyway if I did a direct link to a specific one.
“He didn’t invent the Bell
I know lots of people with the surname Bell and none of them invented anything Bell related
Maybe its just a coincidence?
yep thought so get over it”
Last names usually indicate the family profession. His family most likely at some point made bells for a living, not that they invented them.
Folks, I hate to break it to you, but LASERS DO NOT WORK WELL for open-air optical communications. The atmosphere suffers badly from centimeter-sized convection currents which decoheres the light, leading to a crap-ton of fading and poor quality communications.
High-powered LEDs work much, much, much, much, MUCH, MUCH, MUCH better.
See http://www.modulatedlight.org/optical_comms/optical_index.html