Laser transmitter
Cheap laser pointer
Batteries
Transformer radio shack 273-1380
Solar cell radio shack 274-124 or a photo resistor
Wire
(http://s10.postimg.cc/590pip1lh/670px_Transmit_Audio_With_a_Laser_Pen_Step_5.jpg) (http://postimg.cc/image/590pip1lh/)
connect the 1,000 ohm side of the transformer between the battery and the laser. The 1,000 ohm side of the transformer has three wires coming from it. We only use the outside two wires. The inside wire is called a center tap and we do not use it in this circuit. Test the laser by attaching the battery. The laser should operate normally at this point.
(http://s30.postimg.cc/wig9f738d/670px_Transmit_Audio_With_a_Laser_Pen_Step_6.jpg) (http://postimg.cc/image/wig9f738d/)
The receiver is the simplest part. You simply connect the solar cell to the microphone jack, and plug it into the amplifier or stereo phono input. It does not matter which way the wires are connected to the solar cell. Here is the schematic of the receiver:
(http://s24.postimg.cc/42tebch9d/670px_Transmit_Audio_With_a_Laser_Pen_Step_9.jpg) (http://postimg.cc/image/42tebch9d/)
All Together and working.
https://youtu.be/jvrXXQGXYg4
https://youtu.be/PQkRZ95Zi04
so lovely