what resistor for cree xr, 4.5 source volts

[brentjsimm]

i got the terralux extreme 5 watt drop in for my mini mag. i want to run the lamp with 3 n-cell (4.5 v total) batteries. i'm not sure what type of resistor to get b/c of the wide range of power i can run the led at. please help

 

[Gunner12]

The drop-in has a driver in it so three N batteries might burn out the driver and destroy the drop-in.

 

[brentjsimm]

well, if i was to run a resistor between the batteries and the led, what size resistor would i need?

 

[Gunner12]

My first question is why do you want to run it with 3 N cells(more output?).

The driver(Batteries to driver, driver boost voltage, then power to LED) in the drop-in boosts the 3v input to probably around 3.3-3.6v. Using 3 N and a resistor would probably just lower your runtime.

 

[brentjsimm]

thanks for your help, i'm an idiot. you said that it had a driver built into it. i looked at it and didn't notice a driver though. i was trying to power up b/c i assumed only 3 volts were going to the led. if it up-drives to where i want it, then that's fine. i had a brain fart and didn't realize that it had a driver in it. does the led itself have a driver, or is that something that terralux built in?

 

[brentjsimm]

don't worry about responding. i'm not stupid, i promise. i think i need some coffee. i see what you're talking about

 

[Gunner12]

Don't worry about it, we all have bad days. As long as you see what I was talking about and don't waste your hard earned money by frying the module.