Laser Wireless Audio Transmission Kit Laser Infrared Teaching Experiment Fun Electronic Production Parts



Product Name: Laser Wireless Audio Transmission Kit Parts

Reminder: The kit is mono transmission. If you want to buy two sets of two-channel audio, you can modify the audio input line. The kit does not have a battery, please bring your own 2 9V battery, the store also has a corresponding battery, the purchase of the link below is not a lot of battery power, it is recommended to take a few more. The transmitted audio signal is definitely not wired, the sound quality is good, there is a little noise, and the sound is not very big. It is mainly used for welding practice and fun entertainment. Please take caution when you are concerned.



Transmitter Operating voltage: 9-12V (12V emission distance is the farthest)

Receiver operating voltage: 5 ~ 12V (the higher the voltage, the louder the volume)

Input: 3.5 audio input (computer, mobile phone, MP3, etc.)

Function: computer, mobile phone, mp3 audio transmission.

Transmission distance: 20-50 meters is recommended. The farther the signal is, the more unstable the signal is.

Drive speaker: 0.5W-10W speaker

Transmitter module PCB size: 2.0 * 2.6cm

Receiver module PCB size: 2.2 * 4.0cm

Working principle: The sound is transmitted by infrared laser. The basic principle is to convert the fluctuating sound into a red laser. Then the laser vibration signal is received at the photodiode receiver of the receiver circuit, and the signal is demodulated to achieve sound reduction. The transmission distance can reach 50 meters or so and can be used to manufacture long-distance wireless speakers.


Circuit theory

Transmitter: The audio signal of the mobile phone, mp3, computer, etc. input by the 3.5 headphone port, or the microphone receives the sound and is amplified, and the laser transmitter is driven by the transistor S8050, and the audio signal is transmitted in the form of the laser line.

Receiver: Photodiode receiver tube for receiving infrared transmitter signals, converted into audio signals through the LM386 audio amplifier chip. Audio is amplified to output signals.

common problem:


  1. The transmission distance is short: the normal transmission distance is more than 20 meters. If the signal exceeds 100 meters, the signal will be weak. If the distance is short, check if the voltage at the transmitter is too low. If the voltage is lower than 9V, check if the battery is sufficient. Replace the battery. Also, adjust the transmit and receive angles must be in the same line or otherwise affect the receiving distance and effect.


  1. There is noise: normal operation will have a smile, low noise is normal, if the noise is too large, check whether the photosensitive receiving tube is affected by ambient light, please try to avoid ambient light; 3.5 audio input cable must use high quality shielded wire, Otherwise, noise will be generated by interference; the transmission and reception must be at the same straight line angle, otherwise the sound is too small and the noise is obvious.


  1. The sound is overloaded, please adjust the audio input volume.