mastro14720
New Member
Hi everyone, I am wanting to build a project that uses LEDs to "dance" or react to music. Here is a YouTube video of what I'm aiming for.
The IC I want to use for this is the LM3914. I've tested the chip using a potentiometer as a voltage divider (for the signal source) and it worked great. The schematic I used for this is attached as C1.
When I play music from a phone as the signal source, however, the circuit does not work properly. The circuit I used for this is attached as C2 (it can also be found in the data sheet).
According to the data sheet for the LM3914 IC, the input signal has to be above 0 volts. To my understanding, don't audio signals dip below zero into the negative range? Could this be the reason why it is not working properly? Would I also need to use an op amp for the circuit because the output of a phone or computer isn't strong enough? After doing some digging I found a circuit that seems to solve both problems but I am not sure. This circuit is attached as C3.
The data sheet for the LM3914 can be found at this link:
https://www.ti.com/lit/ds/symlink/lm3914.pdf
Currently I am a sophomore electrical engineering student at Ole Miss, so I am no expert in this stuff. I would appreciate any help you guys could give me.
The IC I want to use for this is the LM3914. I've tested the chip using a potentiometer as a voltage divider (for the signal source) and it worked great. The schematic I used for this is attached as C1.
When I play music from a phone as the signal source, however, the circuit does not work properly. The circuit I used for this is attached as C2 (it can also be found in the data sheet).
According to the data sheet for the LM3914 IC, the input signal has to be above 0 volts. To my understanding, don't audio signals dip below zero into the negative range? Could this be the reason why it is not working properly? Would I also need to use an op amp for the circuit because the output of a phone or computer isn't strong enough? After doing some digging I found a circuit that seems to solve both problems but I am not sure. This circuit is attached as C3.
The data sheet for the LM3914 can be found at this link:
https://www.ti.com/lit/ds/symlink/lm3914.pdf
Currently I am a sophomore electrical engineering student at Ole Miss, so I am no expert in this stuff. I would appreciate any help you guys could give me.