Hello fellow circuiters!
I'm building a project and I need your help!
I'm trying to transmit audio using a laser. Main idea:
Sound source: smartphone
Transmitter: Laser beam
Power source: 5V/9V
Receiver: Solar panel
Sound reproduction: Speakers
There are many implementations in the web but none suits me nor helps me solve my problem.
There are 2 versions that seem to be close the desired outcome. I provide schematics here: https://easyeda.com/AnthonyKpS/Laser-Transmission-with-an-Audio-Amp.
First scenario-Transformer-Only amplification:
Using an audio jack, we take the AC signal from a mobile phone playing music, connect the two ends to the small side of a transformer and receive a higher Voltage signal. Then connect in series the laser, and battery and the two ends of the transformer.
Result: medium volume distored sound
Fix: Place a trimpot between the battery and the laser, lower the voltage to around 2.1VDC
The problem with this fix is that 2.1VDC is marginally close to the minimum Voltage that the laser needs to work properly, thus in any sudden drops of Voltage the laser lights off. Also, considering that the Supply Voltage of the laser given by the manufacturer is 3~5VDC, the laser is essentially underfunctioning.
Second scenario-Adafruit 2130 amplification (Class D Audio amplifier):
Using an audio jack, we take the AC signal from a mobile phone playing music, connect the two ends to the differential input of the Amplifier, connect the power to it and also the connect the two ends of the laser to the amplifier's output.
Result: medium volume distored sound
Fix: Place a trimpot between the battery and the laser, lower the voltage to around 2.1VDC
Same problem.
Third scenario: Tranformer+Adafruit 2130 amplification (Class D Audio amplifier):
I was told that I should try connecting the audio jack to the tranformer and THEN to the amplifier.
Result: very high satisfying volume but also distored sound
Also, on all the scenarios i tried pluging in the system a 9V battery. The only difference was that there were less voltage drops.
As you can clearly see, in the first two attempts the common denominator of the problem is that damn 2.1VDC that if i surpass the sound becomes distorted or not able to hear at all. Why is that? Also, in the third scenario why do you think the sound is distorted?
Any ideas? Any mistakes I've made?
Please let me know!
Don't hesitate to ask for anything that I haven't provided.
I'm building a project and I need your help!
I'm trying to transmit audio using a laser. Main idea:
Sound source: smartphone
Transmitter: Laser beam
Power source: 5V/9V
Receiver: Solar panel
Sound reproduction: Speakers
There are many implementations in the web but none suits me nor helps me solve my problem.
There are 2 versions that seem to be close the desired outcome. I provide schematics here: https://easyeda.com/AnthonyKpS/Laser-Transmission-with-an-Audio-Amp.
First scenario-Transformer-Only amplification:
Using an audio jack, we take the AC signal from a mobile phone playing music, connect the two ends to the small side of a transformer and receive a higher Voltage signal. Then connect in series the laser, and battery and the two ends of the transformer.
Result: medium volume distored sound
Fix: Place a trimpot between the battery and the laser, lower the voltage to around 2.1VDC
The problem with this fix is that 2.1VDC is marginally close to the minimum Voltage that the laser needs to work properly, thus in any sudden drops of Voltage the laser lights off. Also, considering that the Supply Voltage of the laser given by the manufacturer is 3~5VDC, the laser is essentially underfunctioning.
Second scenario-Adafruit 2130 amplification (Class D Audio amplifier):
Using an audio jack, we take the AC signal from a mobile phone playing music, connect the two ends to the differential input of the Amplifier, connect the power to it and also the connect the two ends of the laser to the amplifier's output.
Result: medium volume distored sound
Fix: Place a trimpot between the battery and the laser, lower the voltage to around 2.1VDC
Same problem.
Third scenario: Tranformer+Adafruit 2130 amplification (Class D Audio amplifier):
I was told that I should try connecting the audio jack to the tranformer and THEN to the amplifier.
Result: very high satisfying volume but also distored sound
Also, on all the scenarios i tried pluging in the system a 9V battery. The only difference was that there were less voltage drops.
As you can clearly see, in the first two attempts the common denominator of the problem is that damn 2.1VDC that if i surpass the sound becomes distorted or not able to hear at all. Why is that? Also, in the third scenario why do you think the sound is distorted?
Any ideas? Any mistakes I've made?
Please let me know!
Don't hesitate to ask for anything that I haven't provided.