View Full Version : Noob of the day requesting help

05-27-2014, 10:04 PM
I've spent the last couple days looking over what I could find and I've decided that this might be the setup I want. First, note that I'm not saying to use both green and red, just listing them as options. I'm trying to focus on getting the lighting electronics figured out before I go any further...

Nano Biscotte v2
12mm Anti Vandal Momentary Green Ring Switch
18 ohm / 1/4 W resistor

Rebel Star LED & MHS Heatsink Module (Green)
1000 mw buck puck

Rebel Star LED & MHS Heatsink Module (Red)
700 mw buck puck

Recharge port tbd
Speaker tbd
Panasonic Li-Ion 18650 3.7V 3400mAh PCB Protected Rechargeable Battery

Here's the wiring diagram/calculations I made:

A few questions I have if anyone would be able to help me with :)
1) Am I better off going with the buck pucks or finding resistors to suit my calculations?
2) Are my calculations correct? / Will this all go poof as is?
3) Do I have enough voltage for my chosen setup?

05-28-2014, 05:59 AM
1) The Puck Bucks will not work for those LED's, with the Battery you have selected. (minimum forward voltage requirements for the puck buck is > than the battery)
2) You cannot use Puck Bucks with the Nano Biscotte. (The NB has a Voltage max that is less the the Voltage need by the puck buck)

Puck Bucks are used for "Stunt" builds (no sound), as they offer constant current (which means the blade won't dim as the battery drains, as it would with traditional resistors).

The sound board does not current regulate, so you would need to resistor those LEDs so you don't cook them.
You could get away with not resistor-ing the green, by using that battery, and tweaking the NB settings, but a choice is to resistor as a safety measure.
The red will HAVE to have a resistor, period.

Credit to FJK and SS for posting this answer so many time, even I memorized it!

I'll leave the wiring diagram review to the "experts".

05-28-2014, 07:16 AM
Thanks Kevin. I guess I just need my calculations and wiring checked. Having a hard time finding the right resistors based on my calculations, so I wonder if I got the voltages wrong.

Forgetful Jedi Knight
05-28-2014, 07:47 AM
Your calculations are correct, more or less. You will likely have to "round up" to get the resistors you need (and are commonly made). .5 Ohm 1/2W, 2 Ohm 1W, 18 Ohm 1/4W. Other than that, the diagram looks ok.

05-28-2014, 01:36 PM
Thanks, FJK. I'll see what I can do to find some. I'm just surprised that my calculations come up with something that isn't stocked here because I would think that most of us would come up with the same numbers for common configurations. So the best thing to do is round the numbers up to be safe? How high is too high a variance?

And the next challenge...get the Lithium battery into Canada...hmmm...

Forgetful Jedi Knight
05-28-2014, 01:40 PM
I basically gave you the resistors that you would need. Tim DOES carries 2 of the 3. The calculations themselves are one thing, what is commonly produced by manufacturers is another. While Tim tries to carry the common ones, things change, and it's not always easy or prudent to keep up, so... it is what it is.

06-22-2014, 06:08 AM
I'm getting the tri-rebel GGW as a replacement for the green due to availability and I want to make sure this makes sense before I start wiring.

In this one I'm wondering if it is possible to wire all three LEDs as indicated for sheer brightness and a softer green. I've calculated a .2 ohm .2 w resistor requirement for the two greens, so I'm wondering if I can run them both off a single 0.5 ohm 0.5 watt resistor. Which will actually be two 1 ohm 1/4 watt resistors wired in parallel. The white will be on it's own pair of 1 ohm 1/4 watt resistors.

Next is with the power extender thrown in for FoC. I read somewhere that you can run the positive line right off the battery (plus resistor) without having to go through the power extender and just run the blacks through the PX for the FoC.

Thanks again for all your help :)

Forgetful Jedi Knight
06-22-2014, 10:32 AM
You really should use one resistor per dice. Buying a single resistor is far cheaper than buying a replacement LED when you blow it.

The PEX can be run with just the (-)'s and the FoC control wire.

07-19-2014, 04:59 PM
Is there a thread on how to get batteries legally into Canada? Ive been looking for quite some time with no results ,

Forgetful Jedi Knight
07-19-2014, 05:29 PM
Is there a thread on how to get batteries legally into Canada? Ive been looking for quite some time with no results ,

Welcome to the Forums. You can just buy batteries in Canada. Google Li-ion batteries and Canada and I'm sure you'll find some suppliers.

07-24-2014, 06:12 AM
I've had it done a little while now, but here are some pictures. Thanks again for your help FJK. Things went together really smoothly with only a few challenges. Like trying to tighten that AV switch. Tape on the top of it really helped :)


The only thing I have left to do is add the power extender, which was out of stock when I ordered. I've configured it internally to make it easy to swap out the green tri-rebel with a deep red rebel, and I've ordered a royal blue rebel so I can do the same. Honestly, the red looks a bit goofy with the handle design and the green AV switch. I have plans to make a more Sith styled one as the dent in the chequing account diminishes, and for now I'm going to turn my attention toward making a stunt showpiece only. I'm going to find a nice piece of wood and carve it into a stunt Katana-style hilt. Since the LED could overheat, being wood, I'm only going to use a momentary switch in the circuit so I don't leave it on too long....but I think the design is worth attempting :)

Forgetful Jedi Knight
07-24-2014, 08:17 AM
Looks good. I'm glad to hear it was fairly easy for you.