Believe it or not.We can send the audio with light. Today was fun for friends to play with their children, Learn about the equipment or use a transducer system. The change of light energy. Into electrical energy. And the change of electrical energy into sound.
Change from light to sound.
Light that we see. May be mixed with the audio signal.We normally can not detect it. But this be Light Wave Receiver circuit can tell it, perform take sound signal from the light by modify from the light into pieces hear at a loudspeaker. By the circuit uses LM741 , be IC op-amp the multi-purpose IC. It use for enlarge sound signal , change the way Photo transistor into pieces give hear loudspeaker way well.
You can take the test light. Screen color TV receivers, lighting, home lighting and so on.
But it may not be easy. Need a simple circuit to transmit with light.
LED Tone Generator by IC LM555
This circuit use test waves light receiver signal pulse change LED1. For R1 and C1 be formed control the rate pulse of the circuit. Besides equipment all value in the circuit will give the rate pulse about 600Hz. Other detail see add in the circuit.
Note: LED1 may use infrared light instead. Which results in a distance of about 2 meters.
You may use this circuit. Infrared Remote control transmitter by IC-555-BD137 With the distance far more transmission.