Wiring Question: LedEngin & NB

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02-24-2016, 11:52 PM
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Wiring Question: LedEngin & NB

Hey everyone! I've been away from the saber building gig for years now, but I'm looking to fix that now!

After months of reading threads, I've decided to work with the Nano Biscotte V3 because it's small, easy to work with, and has adjustable parameters. Beyond that, I didn't need the extra features that the CF or the PC featured; I'm a simple dude.
From previous saber builds, I have already acquired a LedEngin GGRB (aka LZ4-00MC00) and a premium speaker from TCSS. I want to be able to use these components in my build, mainly because I don't want the added expense of buying another LED module, especially when I have this one. The NB also arrived today, so I am committed to coming up with a good solution to make these components work.

I've attached a picture of my proposed circuit diagram with what components I want to use and how I plan to wire it all. To my understanding, all the main LEDs, including FoC, are wired in parallel and that the FoC won't be used until the board registers an impact. From the LedEngin's data sheet, both the blue and greens require the same amount of forward voltage, so resistance can remain the same throughout if driven to 1000 mA each. Although, on the FoC, I'm willing to wire the red instead or lower the forward current for FoC and one of the greens to add up to 1000 mA if need be. In such a case, I'll have to recalculate what resistors to use. Should a data sheet be needed, you can find it here: http://www.ledengin.com/files/produc...LZ4-00MC00.pdf

I also plan to make a crystal chamber or use one of TCSS's illuminated switches, so I've also accounted for an accent LED. No specific one yet, but the NB's manual should help me out in my decision.
I tried making Li-Ion batteries work for this build, but there was no way to do it without using a voltage regulator that just trap a lot of heat. Instead, I've found another rechargeable solution with Tenergy's NiMH batteries. They sell a pack that delivers 4.8V and 2000 mAh, which fits perfectly with the NB's max ratings. Thanks to an old thread, I've found a charger that works with NiMH and the TCSS's 2.1 mm adapter wire: http://www.batteryjunction.com/unsmchfornib.html

So, here's the big question: is this good?
02-25-2016, 09:19 AM
Don Se Wion

Actually the NB is designed to work at its best with a single LiIon battery (3,7V).
Using a 4.8V NiMh battery pack can exceed the maximum voltage accepted by the card.

If you want to use the NiMh pack you need to add an 4001 diode (or equivalent) one the positive line between the battery pack and the NB.
As indicated in the NB manual, a fully charged NiMh battery pack can exceed the 5.6V.
Just check diagram and explanation at page 10 of NB v.3 manual.
02-25-2016, 09:39 AM
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Quote:

Originally Posted by Don Se Wion

If you want to use the NiMh pack you need to add an 4001 diode (or equivalent) one the positive line between the battery pack and the NB.
As indicated in the NB manual, a fully charged NiMh battery pack can exceed the 5.6V.
Just check diagram and explanation at page 10 of NB v.3 manual.

Ok, thanks for the tip! I've updated my diagram adding a 1N4001 diode like the manual/you suggest.

Another big concern I had was using a LedEngin in this build, as I've read some mixed reviews about using them with NBs. In theory, this set up should work out fine. What are your thoughts on the matter?
02-25-2016, 09:44 AM
Silver Serpent

Apart from the fact that LEDEngins tend to be power hungry monsters and are a pain to solder? Nah, no reason you couldn't use them. The new Crees (and the older Rebels) are typically brighter than the LEDEngins. That's a big part of why we've stopped using them.

If you've already got one and don't feel like buying a new LED, then feel free to reuse it. It'll be fine.
02-25-2016, 09:52 AM
Don Se Wion

Well, I'm not wiring a Ledengin since years now and I'm at work, but looks like you are picking the wrong pads.
As far as I understand you want to have two dies for the blade and one for FoC.

The cabling mostly depends on the version of Ledengin assembly you have in your hands.
Assuming you have the version where all 4 dies can be wired independently, you need to make few adjustments.

For example the two tiny pads sitting side by side on two of the six prongs (don't know how to call them) are normally positive and negative for a single die (each pair).
The remaining 4 larger pads are matching two by two for the two remaining dies.

I suggest to test each die with a couple of alcaline batteries (3V) to verify the colors connected to each pad.
Blue and Green will not light up much, but you must be fast with the red because 3V are a little high for it.

An additional note, remember to use the thermal pad between your led and the led assembly.
Those Ledengin are dissipating a lot of heat.
02-25-2016, 10:47 AM
face palm

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Quote:

Originally Posted by Silver Serpent

The new Crees (and the older Rebels) are typically brighter than the LEDEngins. That's a big part of why we've stopped using them.

If you've already got one and don't feel like buying a new LED, then feel free to reuse it. It'll be fine.

Good to know, thank you for the confirmation!
I have an idea about how I could make the set up a tad brighter:
Instead of wiring both green LEDs to the board, I've been thinking about wiring just one to the board while wiring the other directly to the battery using the momentary switch to power up the LED and the board at the same time. Knowing the NiMH batteries will vary in voltage, I would plan to use a LED driver to ensure 1000mA gets to the LED. There are also LED drivers that ensure 1200 mA regardless of voltage so that the LED overdriven, which doesn't seem to be an issue for LedEngins as far as I know. If it's working out right in my head, then this setup will still be in parallel.

EDIT: I've just discovered most LED drivers for 1.2 A outputs require higher voltage inputs than what I have :( I may still overdrive it, but use an appropriate resistor instead.

Quote:

Originally Posted by Don Se Wion

I suggest to test each die with a couple of alcaline batteries (3V) to verify the colors connected to each pad.
Blue and Green will not light up much, but you must be fast with the red because 3V are a little high for it.

An additional note, remember to use the thermal pad between your led and the led assembly.
Those Ledengin are dissipating a lot of heat.

I was using the LedEngin's data sheet in wiring considerations, although I could've gotten anodes and cathodes mixed up!
But I've been testing out the pads with alkaline batteries for a while, mainly cause I got bored one day and testing the pads out gave me some degree of satisfaction/motivation to build :cool:
Thanks for the tip on the thermal pad, I probably would have forgotten about it!