Hi guys,
I'm looking for some help, suggestions etc. for a basic circuit i'm currently working on. I've reached my knowledge limit and theres only so much Googling and reading I can do before my head hurts.
I currently have 2 LEDs in my car that I want to 'dance' with the music coming from my car radio, basically increase in luminance with the bass, and stay on a low luminance when there's no or quiet audio. I've attached my current diagram (please excuse the quality, i know it's poor!). I've tried a prototype, and it works but i'm not happy with the design for several reasons, and am hoping someone could give me some help.
1. The audio output of the car radio seems to be at 5v even when there's no audio, so I am assuming that it swings from -5v to +5v to produce the waveform for the speaker. How can I measure the peak output so I know what resistor to use to prevent any high volume audio from causing damage?
2. Do I need a resistor and a diode between the audio output and the base/emitter to prevent negative voltages from damaging the TIP31? If so, what type of diode?
3. Is TIP31C my best option?
4. Any other suggestions, I have a big hunch this circuit is completely wrong even though it does seem to work.
5. Also, i'd like to make a version that switches the LEDs OFF when there is presence of bass audio, and stay on a low luminance when theres little bass or no audio, can anyone point me in the right direction here, are we talking a PNP transistor?
Thanking you in advance for any help you can give, it will be much appreciated!
Dan
I'm looking for some help, suggestions etc. for a basic circuit i'm currently working on. I've reached my knowledge limit and theres only so much Googling and reading I can do before my head hurts.
I currently have 2 LEDs in my car that I want to 'dance' with the music coming from my car radio, basically increase in luminance with the bass, and stay on a low luminance when there's no or quiet audio. I've attached my current diagram (please excuse the quality, i know it's poor!). I've tried a prototype, and it works but i'm not happy with the design for several reasons, and am hoping someone could give me some help.
1. The audio output of the car radio seems to be at 5v even when there's no audio, so I am assuming that it swings from -5v to +5v to produce the waveform for the speaker. How can I measure the peak output so I know what resistor to use to prevent any high volume audio from causing damage?
2. Do I need a resistor and a diode between the audio output and the base/emitter to prevent negative voltages from damaging the TIP31? If so, what type of diode?
3. Is TIP31C my best option?
4. Any other suggestions, I have a big hunch this circuit is completely wrong even though it does seem to work.
5. Also, i'd like to make a version that switches the LEDs OFF when there is presence of bass audio, and stay on a low luminance when theres little bass or no audio, can anyone point me in the right direction here, are we talking a PNP transistor?
Thanking you in advance for any help you can give, it will be much appreciated!
Dan
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