Color Organ circuit question

[avdrummerboy]

Hey all, for those who don't know, a color organ is a fun circuit to build that flashes lights in response- frequency based- to music input from a source.

Anyway, I designed a circuit that uses a signal input that doesn't rely on a built in microphone- most designs that I found online did.

I just wanted to put it up and see if any of you can see anything wrong with the design.

Thanks in advance for anything.

Flickr: avdrummerboy's Photostream

 

[superdiy]

Hi,

You'll have to connect the neutral of the mains to the GND in your circuit otherwise the triacs will not be switched on, because there is no return path. I would however not recommend connecting the mains neutral to the circuit directly, because then you are also connecting the mains neutral to the negative output terminal of the amp and everything else connected to the amp – CD player, mixer etc.

Rather put zero-crossing opto-couplers (triacs) inbetween the 2N2222's and the triacs in your circuit - something like a MOC3041 would work beautifully. Drive the LED inside the MOC3041 with the 2N2222 and use the triac connections of the MOC3041 to drive the triacs in your circuit.

By using the zero-crossing type opto-triacs you will not have any interference on the mains, usually caused by the triacs switching their loads - the zero-crossing opto-triacs have built-in detection circuits which only switches their triacs on and off when the AC signal goes through zero - hence "zero-crossing".

I have added the opto-triac to one of your 4 channels - refer to the datasheet for more info.

 

[avdrummerboy]

Oops 8-O , yeah that would help. Thanks for the opto design idea, that would be a whole lot better than a direct point connection.