LED strip synced to music.

Discussion in 'General Electronics Chat' started by maheshvs23, Oct 22, 2015.

  1. maheshvs23

    Thread Starter New Member

    Oct 22, 2015
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    Hello Everyone,
    I wanted to make a circuit which would make my 12V LED strip glow as per the music beats.
    I am a newbie in these things so I only know to connect components on a breadboard by looking at a circuit. While surfing, I found a circuit which would help me do this. I am attaching the layout of the circuit. I made this circuit on a breadboard and facing one problem.
    Once i start the circuit (by giving power ofc :D), the LED's seem to stay ON the whole time, even when there is no music input from the jack.
    And once i start playing music, the LED's fade to the beat (Which is quite opposite of what I want). The fading is too minor to notice but it does fade on the beats.
    Can anyone help me with this circuit, I am sure i attached these components right and the guy who made this circuit (which I found on Instructables) has the circuit working fine.
    Regards,
    Mahesh.
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  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
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    Pin 8 output of the chip isnt used as there is no input to pin 10 its tied to ground, also the output from pin 14 has a gain of 20,000, i think the resistors are wrong value, change R3 to 1K,and i would put a 10uF cap on the input to pin 12, to block the dc from your music source.

    Also better to draw the circuit out using correct symbols.
     
    Last edited: Oct 22, 2015
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  3. maheshvs23

    Thread Starter New Member

    Oct 22, 2015
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    Thanks for the reply, So I basically need a capacitor on pin 5 in order to make the circuit work?
    Sorry, but I haven't drawn this circuit, this is what I found on an website (Instructables). I dont have a lot of knowledge on these, I just connected the components as per this layout and facing problem.
     
  4. Dodgydave

    Distinguished Member

    Jun 22, 2012
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    Can you post the link for the website you found it on, the capacitor on pin 12 goes in series with the audio signal, + to pin 12.
     
    Last edited: Oct 22, 2015
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  5. maheshvs23

    Thread Starter New Member

    Oct 22, 2015
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  6. maheshvs23

    Thread Starter New Member

    Oct 22, 2015
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    and Btw, I only want to power up like 1-2 metres as I dont have 5 metres of LED strip. So can that be the problem here? Cuz im connecting like 2 metres of LED strip to this circuit?
    Regards,
    Mahesh.
     
  7. Dodgydave

    Distinguished Member

    Jun 22, 2012
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    The amount of leds is dependent on the power transistor and supply voltage, i would start by getting one single led to flash first, then connect the strip leds.
     
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  8. maheshvs23

    Thread Starter New Member

    Oct 22, 2015
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    Okay, so Ill get the capacitor and will check the results, thanks for the help.
    If u find any other solution regarding the circuit without me having to go to buy another component, it would be of great help since the shop is too far from here :'D and I really thought this circuit would work :)
     
  9. maheshvs23

    Thread Starter New Member

    Oct 22, 2015
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  10. Dodgydave

    Distinguished Member

    Jun 22, 2012
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    It looks simpler, again there is no input capacitor to block the DC, try it and see, you need a series resistor in the leds, so if you use a 12V supply and 4 leds use a 180 to 330 ohms resistor.
     
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  11. maheshvs23

    Thread Starter New Member

    Oct 22, 2015
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    Okay, thanks for help! Will let you know when I get time to do it :)
     
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