FOC help

[jediwannabe]

OK this is my first post, now I have done as much research as possible but need some help. I am in the final stages of my first saber build, pics to come. Anyway here are some specs. Gonna run petite crouton 1.6 with two Tenergy 18650's. I need to get a resistor for the FOC, and wondering if one is needed for the main led.

I have an LED Engin 10w RGBA. Main color will be amber so do i need any resistor to run this? The amber specs are 2.5 forward and 700mA with 7.4 from the battery.

FOC is gonna be green the specs provided are 7.4 volts from battery, led forward voltage of 3.5 at 700mA nominal. based on the led resistor calculator, Tim sent me a link, I should use at least a 2.7 watt 5.6 ohm resistor. I can't find one anywhere with these numbers so I am hoping someone can let me know what resistor to use?

I have the resistors for the illuminated red ring momentary switch and the led accent light. I wanted to have this finished so me and my 4 year old can go see episode 1 tomorrow with our sabers. Please help.

[Sunrider]

Read up on the PC manual everything is in there. Do not try to complete the saber in one day. Make sure you know what you are doing first and double check your work.

[Silver Serpent]

Wattage is a minimum value, you can always go with a higher wattage resistor. There is a 10w 5.6 ohm resistor in the store. http://www.thecustomsabershop.com/56ohm-10w-resistor-P20.aspx

700mA seems a bit low for a LEDEngin. I know you can easily drive the green at 1000mA or higher.

The PC will run the primary color of your main LED without a resistor. The electronics will automatically adjust the voltage and provide the current you have specified in the config file.

And I agree with Sunrider. Don't try to rush this. If you get in a hurry, mistakes (sometimes expensive ones) will be made. Episodes 2-6 will be coming out again as well, just in case you don't have this saber completed in time.

[jediwannabe]

Deffinately not rushing this it's already been well over a month since i started, that being said if it's not ready then my saber will stay at home since I cannot cancel on my boy. He can still take his saber I just won't have mine. I am aware of that resistor as Tim also pointed that one out to me but he suggested I go to the pros on the forum to ask about the proper way to do this. I have found a 3watt 5ohm at radio shack and am curious if that would be a safe choice given the minimal time the FOC actually will be firing. Is there another alternative anyone else can suggest?

[Silver Serpent]

It is my understanding that for the FoC you can use a smaller wattage resistor, but I don't know how much lower you can use before you run into problems. Someone else will have to speak up about that.

[Kevin Starwaster]

The PC will run the primary color of your main LED without a resistor. The electronics will automatically adjust the voltage and provide the current you have specified in the config file.

And I agree with Sunrider. Don't try to rush this. If you get in a hurry, mistakes (sometimes expensive ones) will be made. Episodes 2-6 will be coming out again as well, just in case you don't have this saber completed in time.

Ok wait what? What happened to always using a resistor? Right now I'm trying to work out the math on the resistors for a ledengin RGBA.... my cart is waiting for me to add some resistors to it so I can place my order. (I already have the PC)

Is it really not necessary?

[Silver Serpent]

The main LED (the one that lights up the blade all the time) is driven by the electronics in the PC. It's a fully featured LED driver. So you do not need a resistor for that LED.

For everything OTHER than the main LED, (FoC, accent LEDs, etc) you need a resistor.

[Kevin Starwaster]

The main LED (the one that lights up the blade all the time) is driven by the electronics in the PC. It's a fully featured LED driver. So you do not need a resistor for that LED.

For everything OTHER than the main LED, (FoC, accent LEDs, etc) you need a resistor.

Ah thanks... Re-reading the PC manual I think I found the source of my confusion... Page 16 talks about using the main LED to calculate the resistor for the power on LED and I misunderstood and thought the dice on the main LED needed resistoring. sigh. Creeping senility strikes again.

[jediwannabe]

I was able to find a 3watt 8.2 ohm resistor so now I just need to get everything buttoned up