b4tn
Valuable Member
All, I have a surplus of 450nm blue LED's that I want to make dim-able moon lights with. They are standard 5mm 3v 20mA LEDS. I want to make this as simple as possible with what I already have available. I have come up with the below schematic that I wanted to check with the experts and make sure it will work ok. My PWM signal input must be 3.3v @1khz. I cannot change that without messing up my main light fixtures. So that being said, my PWM signal is coming from a PCA9685 and I am not sure if I "need" a transistor or not. As it sits right now I am driving a single blue LED with a 100 ohm resister in series directly off the PW pin and ground with no issues. 4 LED's in series should only draw 20mA according to my calculator so I think that the PWM driver could capable to drive all of them safely but would it be better to add a transistor for a layer of safety? I am open to any advice.
