Hi,

I have device with RGB led which have 4 working states: Red, Green, Blue and Red+Green, my goal is to switch external 12V depending on RGB led states.

I draw this:



It will work or I made mistake somewhere?

Thank you for any advice.

 

Looks like a lot of mistakes from what I can figure, from what you are trying to accomplish I think.
So there are four states, which states are suppose to switch 12 volts and is it a High or Low side switching?

 

There is only high switching.

Blue high -> 12V blue on
Red+green high -> 12V r+g on
Red -> 12V Red on
Green -> 12V Green on

Blue is simple, r+g its AND gate so also.
Red and Green is more complicated that's why I use PNP to off this gates when certain or both transistor are on.

 

How are Q2,Q3 and Q4 supposed to be activated through U4? Does U4 represent simple diodes?
What is this RGB LED device exactly?
Are you trying to get a 12 volt output when any color is activated on the RGB module or just certain colors?

 

U4 is just signal from external RGB LED.

 

U4 is just signal from external RGB LED.

I see that B and R+G are Low side switching, why can't individual R and G not be Low side switching?

 

Cos there is also AND R+G signal and if I do individual when R+G will high, I will have on 3 signals, not only one.

 

A suggestion using diodes D1-D2 to isolate the RED and GREEN.