LED strip synced to music.

Thread Starter

maheshvs23

Joined Oct 22, 2015
7
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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Dodgydave

Joined Jun 22, 2012
11,284
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.
 
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Thread Starter

maheshvs23

Joined Oct 22, 2015
7
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.
 

Dodgydave

Joined Jun 22, 2012
11,284
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.
 
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Thread Starter

maheshvs23

Joined Oct 22, 2015
7
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.
 

Dodgydave

Joined Jun 22, 2012
11,284
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.
 

Thread Starter

maheshvs23

Joined Oct 22, 2015
7
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 :)
 

Dodgydave

Joined Jun 22, 2012
11,284
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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