Uploaded June 2015 | Updated September 2026, 3 weeks ago

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How to make a photophone to transmit sound using sunlight. This invention by Alexander Graham Bell works by reflecting sunlight off a mirror, which is attached to a speaker, to a solar cell and from there to an amplifier.

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For a diagram of how it works, see my webpage here:
rimstar.org/science_electronics_projects/photophone_transmitting_sound_with_sunlight.htm

See also:

How to Make Crystal Radio Amplifier for Speaker
youtube.com/watch?v=JtPwxbOgBHw&list=PLFsZmHTZL-zlSltC6ELZW9PK4ks7wgPRz

Pyramid Hologram - How to Make/How it Works with Princess Leia Hologram
youtube.com/watch?v=UFhhIOaGW7U&list=PLFsZmHTZL-zn3jrI0X0e0aRijWlyvfg8h

How a Prism Works to Make Rainbow Colors
youtube.com/watch?v=UFhhIOaGW7U&list=PLFsZmHTZL-zn3jrI0X0e0aRijWlyvfg8h

The inspiration for this was a comment by Michael Meadows under my video Hand-Cranked Laser - TEA Laser Powered by Wimshurst Machine youtube.com/watch?v=9huUsYDJZrM. Thanks Michael!

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