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Signal build

Laser Transmitting Music

Start with the video, then use the science notes and recommended parts below to follow the idea behind the build.

Radio & soundOpticsAudio

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How it works

What this project is testing.

Light can carry an audio signal the same way radio can. If the laser brightness is varied with music, a light sensor can turn those brightness changes back into voltage.

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This experiment demonstrates optical communication: the beam is the link, and line-of-sight alignment matters because the message is literally riding on changing light intensity.

P_{l i g h t} (t) = P_{0} [1 + m x (t)]

The audio signal changes the laser light power around a steady average level.

I_{p h o t o} \propto P_{l i g h t}

A photodetector or solar cell produces more current when more light hits it.

Recommended parts

Products used in this project.

Affiliate links may earn Keystone Science a commission. Match ratings, values, sizes, polarity, and safety requirements to your own build before buying.

Amazon Basics 8-Pack 9V Long-Lasting Alkaline Batteries for Smoke Detector, Electronics & Audio, Reliable, 5-Year Shelf Life

batterypower

Amazon Basics 8-Pack 9V Long-Lasting Alkaline Batteries

$12.694.7(242K)

General electronics battery pick; choose AA/AAA variants when the circuit calls for them.

Auto Ranging Digital Multimeter TRMS 6000 with Battery Alligator Clips Test Leads AC/DC Voltage/Account,Voltage Alert, Amp/Ohm/Volt Multi Tester/Diode

multimetertest equipment

Auto-Ranging Digital Multimeter TRMS 6000 with Battery, Alligator Clips, and Test Leads

$22.394.6(1,700)

EDGELEC 120pcs Breadboard Jumper Wires 20cm Wire Length Optional Dupont Cable Assorted Kit Male to Female Multicolored Ribbon Cables

jumper wires / hookup wirewiring

120pcs Breadboard Jumper Wires, 20cm Dupont Cable Assorted Kit, Male to Female

$6.984.7(4,500)

Tolako 5v Relay Module 5V Indicator Light LED 1 Channel Relay Module for Arduino ARM PIC AVR MCU

relay / switchcontrol

5V 1-Channel Relay Module with Indicator LED for Arduino, ARM, PIC, AVR, and MCU Projects

$5.694.6(381)

Syncwire 3.5mm Nylon Braided Aux Cable (3.3ft/1m,Hi-Fi Sound), Audio Auxiliary Input Adapter Male to Male Cord for Headphones, Car, Home Stereos, Speaker, iPhone, iPad, iPod, Echo & More – Black

audio source / phoneaudio

3.5mm Nylon Braided Aux Cable, Male to Male, 3.3ft

$7.994.6(119K)

Use with an existing phone or audio player.

Panasonic Portable AM/FM Radio, Battery Operated Analog Radio, AC Powered, Silver (RF-2400D)

AM/FM radio receiverradio

Panasonic RF-2400D Portable AM/FM Radio, Battery Operated or AC Powered

$29.994.5(33K)

WOWOONE Laser Diode 30Pcs 5V 650nm 5mW Mini Red Dot Laser Head, 6mm Outer Diameter Laser Module with Leads, for Arduino Laser DIY Electronics Projects, High-Stability Red Laser Diode

laser / laser pointeroptics

30pcs 5V 650nm 5mW Mini Red Dot Laser Diode Modules with Leads

$12.994.6(152)

Laser safety matters. Keep recommendations to low-power modules and add eye-safety warnings. Review requirements and safety guidance before buying.

SUNYIMA 10pcs Mini Monocrystalline Solar Cells Solar System Kit 50mm X 50mm/1.96" X 1.96" 2V 160MA for DIY Charge Solar Panels

solar cell / photovoltaic panelpower

SUNYIMA 10pcs Mini Monocrystalline Solar Cells, 50mm x 50mm, 2V 160mA

$15.994.5(284)

NoCry Clear Safety Glasses for Men and Women with Anti-Fog and Scratch Resistant Wrap Around Lenses, Adjustable Temples and Nose Pads — ANSI Z87 Certified Protective Eyewear with 100% UV Shielding

safety glassessafety

NoCry Clear Safety Glasses with Anti-Fog and Scratch-Resistant Wraparound Lenses, ANSI Z87 Certified

$13.984.5(49K)

CQRobot Speaker 3 Watt 8 Ohm Compatible with Arduino Motherboard, JST-PH2.0 Interface. It is Ideal for a Variety of Small Electronic Projects.

speakeraudio

CQRobot 3 Watt 8 Ohm Speaker for Arduino and Small Electronics Projects

$7.994.5(457)

Project files

Prints, kits, and downloads.

Diagrams, printable files, kits, or companion downloads will appear here when they are ready to use.

Coming soon

Contact

Events, speaking, collaborations, and news.

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