Is this really the resistor I need

Hey guy's what's up just did a resistor calculater, calculation for red led and I thought I knew what to do but I think it may be wrong. So if I'm running a red off of a tri rebel on a battery that's 7.4 18650 should I need a 8.2 ohm resistor?

battery 7.4
led forward voltage 2.4
led forward current 700 ma
resistor 8.2?? ohm 4 watt capable

It throws me off because with single cell it was only 2.2 2watt capable.

I only ask cause that seems like a lot. also I'm under the impression the watts don't make the world of difference as long as you have the minimum watt capability, out of curiosity does it matter if I use 10w, 5w, 3w, 1w, as long as its at least the minimum.

Please help I got my blue and green good and don't wanna blow my red.

Thanks

Your math is a little off, but not by too much. What Brand of Tri are you planning on using?

A Luxeon Tri-Rebel R/G/B I got from the store around a month ago. An my battery is the 7.4v Li-ion 2600mah 18650 battery from the store.

Thanks for any Help

I got my stuff all working with some help solving problems, but my red LED. I was gonna run two 3.9 5 watt resistors in line on the positive.

1.Will my red Led be safe or am I going to blow it?

2.I only have 3 watt or 1 watt resistors left can I use them to get from the 7.8ohms I should be getting from my 5watt to get to the 8.2ohms I need?

The resistors I have left are a; 2.7ohm 10w, 2x 1.2ohm 3w, 1ohm 2w, 2x .50ohm 3w, 2x 3.9ohm 5w, 2x 3.3ohm 5w, and 2x dynaohm 20ma variable.

How Do I do red? I'm saying 2 3.9ohm 5w=7.8 ohm 5 watt, I should be safe? Is their a better solution with my available resistors?

Can anyone confirm/suggest safety first lol.

If i do the math (7.4-2.4)/.7=7.143. So the 7.8 ohm should be safe, but I am not sure what wattage does with series wiring.

If I'm not mistaken, two 3.9 ohm 5 watt resistors wired together will result in 1.95 ohms resistance and 10 watts.

Excerpt from NB manual...

"Without going too much into boring details, there's a simple rule of the thumb sayingthat wiring 2 identical resistors in parallel divides the resistor value by 2 and multipliesthe wattage by 2. "

Edit: Ah I see. Wiring them in series does add the resistance together. Parallel halves the resistance.

Got it all together now I have red, green, or blue. All you have to do is switch out the connections via jst connectors. I used my original blueprint with a slight modification. I have figured out a double light set up with three colors and three combos all with one switch of color, once again via jst. I have red going female to a split output male on the switch converter and green to buckpuck which is connected too the second split male on the switch converter. To switch color all you do is dis connect any color an connect the third unused color. this set up requires two switches for now but here it is haven't wired it all yet will do tomorrow.

Red to male Green to puck= red/green/orange orange is both colors also can do yellow with Mywire. I have a variable version where I throw a linked female to female wire with two 3.3ohm 5w resistors on it for green or blue; yellow sunriders, purple.

Blue to puck green variable to male= green/blue/sunriders

Red to male Blue to puck= red/blue/pink, purple

I tested all the resistors on everything I'm gonna do my split female to male, male for the momentary out tomorrow. Then Im going to make that female, female 6.6 ohm resistor link. I tested it all with gator clips all except running two things off the momentary switch converters battery out at the same time.

I will post a walkthrough and diagram with a item list when I'm done so the next guy doesn't go through the same struggle. I couldn't find anything on this style of set up an it is fairly cheap solution to doing more then one color stunt saber without buying a soundcard or a color blender.

Let's hope the momentary switch converters out can handle powering 2 LEDS at once

Thanks to all who helped. just thought of problem, you could only do red then orange because the momentary would have to be on for the green to work. huh thought I had something O well gonna work it out tomorrow I'm sure.

edit(took 5 mins lol) Solution I will move the female to double male output wire I make to the battery=female and to the switch converter=male and buckpuck=male solves that and the question if the converter could handle to outs because it won't need to.

This also Gives manuel FLASH ON CLASH



Attachment 13782

Got It will post a video of the FOC soon

I never soldered my link for blue/green combo yet either, I need it for emerald green or orange. I had work today so I will finish that after work tomorrow.

Heres my colors so far

Attachment 13808