Cg2 Controller Leds Options

[Weirdjerz3y]

Hello all, Im modding my CG2 Controller. Its going to be Black and red. With the red Transparent for leds. My problem is at first, when I had 4 leds, it was nice and bright. I added two more, and they are extremely dim. I want them to be always bright, Like my XCM Light up controller shell. I was reading about posting here, to see how to make it bright, but i didn't find much. I found out about a Charge pump or DC-Dc converter, my problem is, how will i build it?
here some pics of how I installed them. If anything is wrong, or out of place, please tell me. I want this controller to come out nice and bright. And the controller is going to have quite a number of leds. Im going to light up the dome, joysticks, XYBA buttons, and if possible or i got space the d-pad. I already did the triggers, and bumpers.



^This was before I added more leds, and added the transistor.



^my XCM controller, Its always bright, even if its about to die. But the MB on it is a Matrix.
*ignore mess in background, I took these after adding some more leds.
I'm not sure how to resize pictures, so if they are big, sorry. And Thank you for looking at my current project, and helping me out with it.
-I forgot to mention, I have a Pre-programmed RapidFire chip under the pcb, Thats why you see extra wires going to different places.
The PCB itself is for the negative and positive wires for the leds. So all it goes to one easy location.

This post has been edited by Weirdjerz3y: Apr 28 2012, 07:48 AM

[RDC]

Using the Transistor for the LEDs is fine, and they will handle more current than an OC as well, so it's better to use a Transistor for this.

There should be 2 Resistors on the Transistor, one on the Base (around 1k or so is fine), then one form the Base to Emitter (around 10k or so) so it turns the thing completely off. The BE Resistor isn't always needed, but it's good practice to use it.

A Resistor should always be used on an LED, unless the voltage you're driving it with is under the LED rating, but in this case it both is and isn't.

If the LEDs are spec'd at 1.9v-2.3v then they could be going bad, or the spot you're using for power can't source the current. The 2 x AA batteries are ~3.4v when new, and even if you're only using PnC batteries they are ~2.7v fully charged, which drops to 2.2v when they are low. That line also has 3.3v on it when the PnC cable is plugged up, and even minus the voltage drop thru the Transistor, you're still overpowering them with new AA or when charging batteries. So you're throwing over 2.3v into them at that point, until the batteries drain some, so they would need a Resistor for sure at that point but then they don't when the batteries get low.

This is the main reason sticking LEDs in the controller 'as-is' never flies, because there is no good regulated source for driving them and where an LED driver or DC-DC is useful, but the more you stick in there the shorter the battery run time is going to be also.

Since those are Red LEDs and they have a lower voltage, you could also use a Regulator set around 2.5v or so and use that as the power source, that way the LEDs would never get any more than ~2.2v or so (less than the 2.5v because of the Transistor voltage drop) but they're still going to dim some when the battery level gets under 2.5v, and it will since the controller can still run on 2v or so.

If you're really wanting to put in at least 5 more LEDs, plus the 6 already in there, you're looking at a 220mA current draw, which is far more than the controller uses just on it's own, so the 30-40 hours of run time it had on the batteries will be a thing of the past.

Anything you use will need to handle around 500mA to be safe with that many LEDs, Regulator, LED driver or DC-DC, any method will need to be able to source that current to drive all of those LEDs.

You could go with some Buck or maybe Buck-Boost LED driver, but you're looking at an IC to do that, plus it's support circuitry, and some math to get it all working right with your setup, and making up a PCB for it would be the best way to go there, plus it would also cost the most.

The most simple thing to do would be to just use a 2.2v Regulator and a manual switch so there's no voltage drop to deal with. The Transistor could still be used, but the LEDs are still going to dim some when the battery voltage drops.