Circuit Diagram of Wireless Audio Transfer Project Using Laser Light

Components Required for Wireless Audio Transfer Using Laser Light Project

Below is the list of required components to build the Wireless Audio Transfer using a laser light project. Some components may have alternates. To learn more about that, read the “Concept of Audio Transfer Via Laser – Explanation” available above.

1. Solar Panel – x1

2. Laser Diode – x1

3. Resistor (30 ohms) – x1

4. Potentiometer (100k) – x1

5. Speaker (4 ohms, 10W) – x1

6. MAX4466 Microphone Amplifier Module – x1

7. 7805 5V Voltage Regulator – x2

8. PAM8403 Audio Amplifier Module with Potentiometer – x2

9. 9V Battery – x2

10. BreadBoard – x2

11. Jumper Wires – Required Quantity

Circuit Diagram of Wireless Audio Transfer Project Using Laser Light

Here this project is built by keeping in mind that to make it easy and use only Minimal components. So, as an outcome, the circuit is simple for Everyone to understand and recreate.

Transmitter Part:

Here you can see the Schematic of the transmitter part. Those connections are self-explanatory.

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We can split the schematic into two parts: The power and Transmitter Section.

Power Section:

Here, the power source selected is a 9V battery. Since the rest of the circuit operates at 5V, I am using a 7805 5V Linear Voltage Regulator to effectively convert 9V to 5V.

Transmitter Section:

In this section, only four components are being used.

Both the MAX4466 and PAM8403 modules are powered using the 5V output from the voltage regulator. The output of the MAX4466 Microphone Amplifier Module is connected directly to the PAM8403 Audio Amplifier Module.

The PAM8403 supports 2 channels. You can use one channel alone or use both channels as I have. However, we are going to drive only one laser. The laser’s positive and negative terminals are connected in parallel with one of the channels. While connecting, I have mentioned using a 30-ohm resistor in series. This is for limiting the current flowing through the laser diode. If you are using the same laser diode as me, this resistor is not needed as it already has a 30-ohm resistor connected internally.

Receiver Part:

Below you can see the schematic of the receiver part. You might notice a similar power section here like the transmitter part, as our requirement is still the same. We are powering the system using 5V.

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Receiver Section:

Here, the solar panel’s negative side is grounded, and the positive side is connected to the input of the PAM8403 Audio Amplifier Module. Like the transmitter, I kept both input channels connected. An extra step is applying the bias voltage to the input using a potentiometer, which sets the DC offset to the input of the amplifier. Finally, a speaker is connected to the output of the PAM8403 amplifier module.

That completes our circuit. Next, let us move on to the assembling part.

Building the Circuit

Let’s build the circuit according to our schematic. I am using a breadboard to assemble all the components.

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Above, you can see the assembled image of the transmitter with its parts marked for your reference. The laser diode is directly soldered to a 2×2 Berg strip connector, allowing it to be easily fixed to the breadboard. Similarly, the battery connector is also fitted with a Berg strip for easy breadboard integration.

In this transmitter, there are two configurable areas. One is the gain adjustment in the MAX4466 Microphone Amplifier Module, which controls the sensitivity of the microphone. The other is the amplitude adjustment in the PAM8403 module, which controls the output power to the laser diode. These configurable options allow for precise signal control.

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Above, you can see the assembled image of the receiver. Parts like the speaker, solar panel, and battery are connected to the breadboard using Berg male strips, which I have soldered to the wires and fixed to the breadboard.

Like the transmitter, the receiver also has two configurable options. There is a potentiometer connected to the input of the PAM8403 module, which is used to set the DC offset to the input signal. The PAM8403 module itself has a potentiometer to adjust the amplitude of the signal going to the speaker, effectively allowing volume adjustment.

With this, we have completed building the circuit as per the schematic diagram. Next, Working demonstration.

Working Demonstration of the Wireless Audio Transfer Project

After successfully assembling the components, we began testing the project. It works well both indoors and outdoors, regardless of the conditions. The range of the wireless transfer is impressive, as the intensity of the laser does not diminish significantly under clear weather conditions. As long as the laser beam hits the solar panel, the audio is transferred seamlessly. We also tested the setup from multiple angles and encountered no issues.

The image above was taken while testing the setup outdoors. Unlike other projects, I did not include any GIFs to show the working process, but we have made a video that you can watch below. The video provides a complete demonstration and explanation of the project.