For ages I’ve wanted to have a go at building a version of Alexander Graham Bell’s photophone. I had a very informative conversation about this with the artist known as Crank Sturgeon a year or two ago and saw an excellent version Anthony Hall had built using a voice recorder, LED and speaker a couple of months back.
I was prompted into having a good think again today about the photophone by a visitor’s question when discussing some of our current circuits.
“How old is the photoresistor?”
The oldest example I could think of off the top of my head was the use by Bell in the 1880s in the photophone. And so a fun afternoon of building ensued…
This post by Anthill Social was very useful and by the end of the day I had one of our oscillators outputting light via an LED and a photoresistor receiver picking up the sonic information via the light and out through a mini amp. An excellent result! The next step would be to replace the LED with a laser so sound could be sent over longer distance.