This is a very interesting project for beginners. We had made a similar project several years ago and published on BuildCircuit.COM. Check out this page. In this project, music from an audio source can be transmitted wirelessly.
There are two kits included in this package. One is a transmitter and the other is a receiver.
On the transmitter side:
On the transmitter side, music is fed to the circuit and it is transmitted to infrared LED via an amplifying transistor so that the audio signals can be transmitted as infrared rays. If you connect a speaker in place of the infrared LED, the kit would work as a simple amplifier.
On the receiver side:
On the receiver side, there is a phototransistor working as an infrared receiver which takes the audio signals in the form of infrared and feeds to the audio amplifier LM386 and the audio amplifier amplifies the signal and consequently produces sound.
The assembly of this project is very straightforward. You can easily assemble this kit if you have basic knowledge of soldering.
How does it work?
Operating voltage: 12V- You can achieve reception up to 1 meter if you use 12V, Otherwise, 5V-9V would transmit about 300cm only.
PCB size: 19 * 25mm
Operating voltage: 4 ~ 12V
Driver Speaker: 0.5W-10W Speaker 1
PCB size: 17 * 39mm
The schematics are given below:
Package Includes: All the Components required to build infrared-based receiver and transmitter modules.
Components for receiver: Altogether 16 components including PCB
1. 2 x 0.1uF ceramic capacitor- Code 104
2. 1 x 0.22uF ceramic capacitor- Code 224- The PCB has 223 printed on it instead of 224. It is a mistake by the manufacturer.
3. 3 x 100uF/25V electrolytic capacitor
4. 1 x 10uF/25V electrolytic capacitor
5. 1 x 5mm LED
6. 1 x 1K Ohm resistor
7. 1 x 620K Ohm resistor
8. 1 x Phototransistor
9. 1 x LM386
10. 1 x IC header for LM386
11. 1 x Two pin screw terminal
12. 1 x 9V battery connector
13. 1 x PCB
Components for transmitter : Altogether 11 components including PCB
1. 1 x PCB
2. 1 x Earphone Jack female- You can connect a speaker also
3. 1 x Infrared LED
4. 1 x 100uF electrolytic capacitor
5. 1 x 4.7uF electrolytic capacitor
6. 1 x S8050 transistor
7. 1 x 5mm LED
8. 1 x 0.01uF ceramic capacitor- Code: 103
9. 1 x 100 Ohm resistor
10. 1 x 51K Ohm resistor
11. 1 x 9V battery connector