I'm wanting to smooth a PWM LED signal being used as a trigger for additional lighting. Right now it has some relay chatter at fade on and fade off. Everything is 12v and the trigger is the negative line of the LED being tapped (Toyota). What I've researched says to use a 470ųF rubycon capacitor across the pos and neg inputs. Also wanting to double check check the orientation is correct. I've seen one of these firecracker with someone else.

 

Please do not connect the DC power supply to the power line.
You need a power supply.

 

Please do not connect the DC power supply to the power line.
You need a power supply.
View attachment 370483

Why not?

What power supply is he going to use, if he can't use the 12 V power from his Toyota's battery?

The capacitor across the DC power inputs for the control side is unlikely to do what he wants (though there's no harm and some benefit, especially since it doesn't look like there's any decoupling capacitor on board (but maybe I'm just not spotting it).

He says that it is chattering at fade in and face out, which argues that the problem is a lack of hysteresis, which would be a problem with or without the use of PWM, but the PWM probably aggravates it.