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View Full Version : How sweet that sound is! Only you guys know.



rrvancelette
05-03-2016, 08:34 PM
Let me just start by saying thank you to all who answer and read these post. I have been building sabers for years and coming to this forum as long. I don't post much and I read everything. Most of the sabers I have built have been for others and always with no sound. Tried my hand at some MR boards and did well and felt the time was right to spend the money on some good boards. I got a NB 3 And CF 8.. Whoohoo.... only you guys know the satisfaction of that first bench test, after months or sometimes years acquiring all the parts for your ultimate saber, after days of learning and wiring, you pull that kill key and Boom...AAAAHHhh That sound.....Thanks everyone for all the great posts. Now I have everything wired to my NB I need to hear some opinions and one more question answered. I have 10 12w RGBW leds. The specs are
* Brightness: red: 70-90LM green:140-160LM blue:30-50LM white :160-220LM
* Wavelength: red: 620-625nm; green:520-525nm; blue:460-465nm; White 6000-7000K
* Forward Voltage:red: 2.2-2.5v green:3.2-3.4v blue:3.2-3.4v white :3.2-3.4v
* Forward Current: 700mA
I want to have the brightest that I can and my color will be green. But with this led I could use a small 3 position slide switch and have a red, green or blue blade and use white as FOC. Or I could get this from the custom saber shop
Green/Green/White Cree XP-E2 CopperNova

Green Cree Part# XPEBGR-L1-0000-00G01
130 Minimum Luminous Flux @ 350mA
Forward Voltage @1000mA = 3.58v

White Cree Part# XPEBWT-L1-0000-00F51
266 Minimum Luminous Flux @ 1000mA
Forward Voltage @1000mA = 3.15v
So I guess my question is. Is the tri-cree that much brighter that I would chose that over having three colors. And Please Ohms law is killing me Cold you please tell me what resisters I would need.. Thanks again..
And This is the battery I use
Li-Ion 18650 3.7V 2600mAh PCB Protected Rechargeable Battery Module

Silver Serpent
05-04-2016, 04:58 AM
The GGW Tri-Cree is going to be quite bright.

Another option would be to use a BBW Tri-Cree and a Photon Blade. You'd have a blazing green blade, and you could swap that blade out for a normal blade to get blue.

For Ohm's Law, look at the links in my signature. The three pieces of information you need are your battery voltage (3.7v), the forward voltage of your LED, and the current you wish to run the LED at. All that info on wavelengths and luminous flux is not important when it comes to calculating your resistor.

rrvancelette
05-04-2016, 07:54 AM
Thanks Silver Serpent, So i'm going to try to wrap my brain around this. I know it's probably easier then I think. So (3.7v-3.58v)=0.12 So all that's left is current correct? which is 1000ma? Here is where I get lost. I know resistors need to be rounded up and looking at the resisters at the CSS They all, except the 20mA DynaOhm have (18ohm 1/4w resistor)So what does the number 18ohm mean? and 0.12 would be rounded up to a 1/4 w?

rrvancelette
05-04-2016, 08:01 AM
I have found someone else who asked the same question and his calculations was the same as mine on the first part 0.12.. And he was told to use 0.47 ohm 0.5 watt. Now great that I found an answer, but does not help me learn to do it myself. Still a little unsure.

Greenie
05-04-2016, 08:04 AM
The lowest value resistor in store is, I believe, 0.47ohms. 18ohms probably won't even light the LED.

rrvancelette
05-04-2016, 08:07 AM
OK.. But what does that last number mean and how does it factor into the equation?

Silver Serpent
05-04-2016, 08:37 AM
Thanks Silver Serpent, So i'm going to try to wrap my brain around this. I know it's probably easier then I think. So (3.7v-3.58v)=0.12 So all that's left is current correct? which is 1000ma? Here is where I get lost. I know resistors need to be rounded up and looking at the resisters at the CSS They all, except the 20mA DynaOhm have (18ohm 1/4w resistor)So what does the number 18ohm mean? and 0.12 would be rounded up to a 1/4 w?

You're right, it's easier than you think. Your current is 1000mA, which is 1A. Plug 1A into the equation for current and you'll get your ohm value.

R = (3.7v-3.58v) / 1A = 0.12 ohms. That's roughly a 1/8 ohm resistor.

To figure out the wattage, you MULTIPLY by current instead of dividing.

W = (3.7v-3.58v) * 1A = 0.12 watts. Any resistor with at least 1/8 watt rating is good. 1/4 watt, 1 watt, 3 watt, they'll all work the same. Be advised that higher wattage resistors get BIG and take up a lot of precious room in your hilt.

There's a 0.47 ohm 0.5 watt resistor in the store that does the job nicely. Honestly any value below 1 ohm is negligible, so you're adding it to keep the LED from overdriving itself.

rrvancelette
05-04-2016, 09:03 AM
Just to make sure i'm getting this. If i'm using a red that is..((3.7 V) - (2.59 V)) / (1 A) =
1.11 ohms. So I would round up and use 2ohm 1w resistor. yes?

rlobrecht
05-04-2016, 09:48 AM
Round up. The next up from 1.11 ohm 1.11 watt is 1.2 ohm 3 watt.

rrvancelette
05-04-2016, 09:56 AM
I get it! I was thinking that the number 1.11 ment 1w 11ohm But I get it now. Thanks all you great people for helping me out.
Give a man a fish you can feed him for a day.
Teach a man to fish you can feed him for life..;)

DarthFender
05-04-2016, 05:07 PM
Another satisfied customer.