Pico Crumble V2 resistor question

I'm trying to work through my first wiring of the Pico Crumble V2 to the Tri-Rebel RGB LED both sold here on the Custom Saber Shop. I wired everything exactly like the Pico's owners manual - which lists using .5 1w resistors. I bought those and connected it - I'm able to fire it up and at first get through a couple of clashes before it completely shuts down (no shut-down sound - just goes dark). I suspect the resistors are incorrect.

The trouble is, though the calculations are easy to go through (I use http://ledcalc.com) the listing on the LED itself is not. The Luxeon Tri-Reble Star information on the CSS says: (http://www.thecustomsabershop.com/Lu...Star-P777.aspx)
- Lumen ratings at 700mA
- Red/Green/Blue = 90-161-58
- Red should be ran at a max of 700mA but the other colors are good up to 1000mA

So what are those numbers by "Red/Green/Blue?" If I enter them as the "Voltage Drop Across the LED" the resistor cannot be calculated. So, I use the recommendation on the calculator for a "Super Bright Red" which is 2.2

I entered the following in the calculator:
- Red
*Supply Voltage = 3.7v
* Voltage Drop Across LED = 2.2
* Desired LED currant = 700mA
* Connected to 1 LED

This gave me the 2.2 ohm 1w resistor. What say you, is this correct?

I used three 0.47 ohm 0.5 watt resistors wired in series for my deep red, so that is basically a 1.4 ohm 1.5 watt resistor. I think a 2.2 ohm 1 watt resistor should work, however you could put up the wattage and lower the ohms a bit.

Quote:

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Originally Posted by Seth Skywalker

I used three 0.47 ohm 0.5 watt resistors wired in series for my deep red, so that is basically a 1.4 ohm 1.5 watt resistor. I think a 2.2 ohm 1 watt resistor should work, however you could put up the wattage and lower the ohms a bit.

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So did you do that with the Pico and Rebel Tri-Cree? How did you arrive at that calculation? Is mine incorrect?

I used the nano biscotti. It doesn't make a difference if you use the nano or the pico, if you have the same battery supply, after all you are using a 3.7 volt battery source. I however used a Tri-Cree not a Tri- rebel. I will always suggest to calculate the resistors yourself instead of an online calculator. It's both easy and more accurate. If my calculating is correct, a 1.85 ohm 0.9 watt resistor should work. If I am incorrect please someone step in and correct me.

I dunno, that shut down to be sounds like a short somewhere, not the resistors. Then again, I'll defer to the experts here.

Quote:

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Originally Posted by Seth Skywalker

I used three 0.47 ohm 0.5 watt resistors wired in series for my deep red, so that is basically a 1.4 ohm 1.5 watt resistor. I think a 2.2 ohm 1 watt resistor should work, however you could put up the wattage and lower the ohms a bit.

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Wiring resistors in series like that will add up the ohm values, but wattage remains the same as the lowest resistor.

3x 0.47 ohm 0.5 watt resistors would be the equivalent of a 1.41 ohm 0.5 watt resistor.

CDSabers, your 2.2 ohm 1w resistor is correct.

Quote:

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Originally Posted by Silver Serpent

Wiring resistors in series like that will add up the ohm values, but wattage remains the same as the lowest resistor.

3x 0.47 ohm 0.5 watt resistors would be the equivalent of a 1.41 ohm 0.5 watt resistor.

CDSabers, your 2.2 ohm 1w resistor is correct.

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Thanks for correcting me, I will be more careful with my answer next time.

I think it is most likely a short circuit or an unstable connection.

If you are using a spring-clip type battery holder (Ex: http://www.thecustomsabershop.com/2A...ctor-P722.aspx ) then you may be losing battery connection briefly when you have a clash event. Hardwired batteries will eliminate this problem.

Sometimes you want removable batteries for various reasons (extra run time during trooping sessions, no room on hilt for charge port, personal preference), but it's something to consider when designing your saber.

Also, be sure your battery is fully charged. They don't necessarily come at 100% when you get them from TCSS. Low batteries are probably the #1 cause of issues for a new saber builder.