12w LED + Nano Biscotte Problem

[Circles]

I have attempted to wire a saberforge 12w LED to a Nano Biscotte V2 (using the PEX hack). When the LED is unplugged it works great, but when plugged in there is a large amount of static coming from the speaker. Sometimes the swing sounds will repeat over and over again. Does anyone have insight on this issue? Also, the resistors I am using for the LED are the ones saberforge have installed. Battery is 3.7v Panasonic 18650.

Here is a video demonstrating the issue:
http://youtu.be/WRJsFmZUrZM

Pictures of the wiring have been attached.

[Forgetful Jedi Knight]

Welcome to the Forums.

The problem you have is not surprising given the facts as you have stated them. The "PEX hack"? What/How exactly did you do the "hack" and what were you trying to accomplish?

[Circles]

Thank you for your response!
The "PEX hack" is required when one uses a 12w LED with the Nano Biscotte. If I am not correct, the transistor from the Power Extender gets wired to the transistor on the soundboard, so the led is using the PEX transistor instead. The Nano Biscotte can't power a 12w led so the hack is required. There are some others that have successfully done this numerous times, noteabley (youtuber) Shameem.

[Forgetful Jedi Knight]

I am aware of what the "hack" is suppose to accomplish.

Basically people are trying to make the NB "do more" than it is suppose to (or more accurately - designed to), and the side effects you are experiencing are the result. Offhand, I would say that the resistor you (or whomever) used isn't "strong enough" for your purposes.

[Circles]

Could it be possible that both transistors are combining? Resulting in the need for a larger resistor. Right now the led is resisted for a 3.7v battery.

[Forgetful Jedi Knight]

Could it be possible that both transistors are combining? Resulting in the need for a larger resistor. Right now the led is resisted for a 3.7v battery.

OR whomever did the resistor calculations, did them wrong. Given the LED you are using and where you got it from, that would be my suspicion.

[Kouri]

Did my own bit of digging, and if you're going to insist on trying the hack, this appears to be the recommended diagram:

12496

I'm going to guess that where you're currently wired up runs into the audio circuit, causing the static.

Also mentioning that this is just what I've found - I haven't tried this myself, nor do I intend to. I'd personally prefer a board that can handle the 3-4A of current a quad-cree like yours would be asking for.

[Circles]

Yeah, I was going to do it that way, but was too weary since it's so small. I'm going to try it though and if that doesn't work, I'll look into different resistors. I'll repost my findings; thank you all for your help! This is my first saber build.

[Forgetful Jedi Knight]

You might want to consider scrapping the 12W and using a Tri-Cree, Just 2 of the Tri-Crees (without any "hacks") would probably be brighter than the LED you currently have.

[Circles]

I'm definitely going to try the Tri-Cree for my next saber, but I want to try and work out the 12w. I just rewired the led according to the diagram and nothing changed. I am now going to attempt to figure out if it is a resistor problem. I understand finding the right resistor for a single LED, but how would I go about finding a resistor for 4 LEDs in parallel?

[darth_chasm]

One on each die is the recommended way.

[Circles]

After a lot of messing around, I noticed that the static matched up with the flicker of the LED. I then set the flicker on the Nano Biscotte to 0 and the static sound is gone. No idea why this is, but I can live with it. I have one more concern though. My LED flickers for a split second when I pull the kill key, is there a reason for this?

[tsaiphil]

Maybe a short' double check the wires and battery.
Not a big fan of 12W LED, it gets super hot.

[Jay-gon Jinn]

If you guys are using that led because it's "12watts", you might want to read this over: http://www.ledsupply.com/blog/1-watt-3-watt-high-wattage-leds-explained/