LED Dimming Question

[SquidwardTentacles]

Hopefully I won't get told to rethink my plans or anything with this question (JOKE!).

I've done some looking online and not sure I have it figured out yet so I'm asking others that have done it.

On my new JBJ nano, I have 25 three watt white (very white) LEDs. I've added seven blue stunners which has helped a ton. However, I'd like the capability to dim the whites. I am aware of the reason this is not included in the manufactured product (over-reaching patent).

I have found a few options but rather than burn cash on some that may or may not work, I figured I'd ask here...


Thanks,

Squidward

 

[SkiFletch]

What are the drivers for the whites? Is it some stock thing, or did you DIY them in the first place? If stock, are you willing to have some fun with the original design?

 

[SquidwardTentacles]

The stock LEDs are what I'd like to dim. 700mA. I was looking at some DC dimmers but not sure about them. I've got some good blue in there with the Stunner Strips but I am out of room for many more mods in the canopy.

 

[SkiFletch]

Well, depending on how the driver functions, it may or may not have inherent ability to simply lower the input voltage via a "dimmer" and lessen the output of the LED's... The driver IC itself might be fine with it, but if there are fancy DC/DC power supplies in there that convert your input voltage down to some control voltage, they may not operate at too low of an input. Then without control voltage, the IC's won't even come on. It's unlikely to damage them by trying that, but I'd want to KNOW before I tried .

The way to find out would be to crack the case on whatever stock controller they come with, see what kind of regulator they use, and then determine if that regulator has dimming control built-in, or will be "ok" with lower input voltage. Many IC's have dimming control options built-in that manufacturers just don't bother using via either SIMPLE pwm controllers, or just analog voltage input. If that's the case, you could just lift the dimmer, supply it with your own small/simple circuit, and have the control you want.

 

[SquidwardTentacles]

OK, thanks for the input. You obviously have some experience in this field. A neighbor of mine is a rocket scientist for NG. I'll get him to take a look. I am pretty good at electrical, but this is a step up for me.

Thanks again.

 

[SkiFletch]

I'm surpised dwzm hasn't replied here too. He's the LED driver guru .

 

[der_wille_zur_macht]

I usually don't touch computers on weekends. Too busy with this other thing some people call "the real world." :lol:

Agree with what's been said though. It's probably not likely that it will be "simple" to dim a commercial product that wasn't intended to be dimmed, but you never know. A good up-close photo of the PCB inside the driver might let us give you some help, but the best option is probably to replace the driver with something that has dimming capabilities out of the box. And given that most of these types of unit are highly integrated, that might not be very easy, either...