where does the resistor goes in this driver?

[Gofilord]

1.5V~4.2V 3W Cree Circuit Board for Flashlights (16.7mm*5.6mm) - Free Shipping - DealExtreme

this is the driver and it has no pot. I have to have some way of lowering the current and a forum member told me to hook a resistor (for my needs a 2.7 ohm) but I have not idea where to connect it.
I thought on the red wire straight to the diode..

 

[Cyparagon]

You need to replace the sense resistor. It will be the resistor that heats up the most during operation.

 

[Gofilord]

how do I recognize this sense resistor without messing up my diode?

 

[Eudaimonium]

Dude, there's only one resistor on the entire god damned board.

It even says in the review down there, quote:

Pros:
You can get higher current buy resoldering R150 resistor to R100 (0.1 Ohm). To get more stable output add 10mF solid capacitor to both tantalum on-board (total 2 of 20 mF).

Don't make me photoshop fifty arrows pointing to it on the picture of the board.

 

[bennett326]

has anyone tested those drivers they look pretty sweet

 

[bobhaha]

Dude, there's only one resistor on the entire god damned board.

It even says in the review down there, quote:


Don't make me photoshop fifty arrows pointing to it on the picture of the board.

Do EEETTT!!

 

[Flaminpyro]

Come on I want to see all them arrows :crackup:

Dude, there's only one resistor on the entire god damned board.

It even says in the review down there, quote:


Don't make me photoshop fifty arrows pointing to it on the picture of the board.

 

[Eudaimonium]

Alright,

I thought a dozen or so should do it.

If you are still having trouble identifying the component, paypal me some munies to get the rest of them arrows. Seriously, that's like 40 arrows for spare change! Free shipping! Guaranteed to unmistakenly help you identify your god damned resistor! One time deal!

 

[Gofilord]

hahaha LOL thanks.
you say I should remove it and put a 2.7 resistor in spot?

 

[Eudaimonium]

Nope, it works the other way around - smaller the resistance = more current you're getting out.

Now, what current are you trying to get out of it? It says on DX that it's rated for 1.2 Amps output if lithium ion cell is used as power supply which should be good for 445nm diodes.

What diode will you use it with?

EDIT- Oh and sorry if you were offended in any way by what passes for my version of "joke" up there No offence was intended.

 

[Gofilord]

PHP diode, and I'm trying to get 93mA. also, I wanted to know if 3V is enogh

 

[Eudaimonium]

Well, I bet 3V is enough.

Now, to lower the current, if 1.2A is supplied by it out of the box, you'd need 10x smaller current which means 10x larger resistance so ... yeah, 2.5 to 2.7 ohms should do well.

Let us know how it goes

 

[Gofilord]

Yes so going back to my second question:
do I have to pull out the existing resistor and somehow put the 2.7 ohm in?

 

[Eudaimonium]

Yes, you need to remove it.

There are a good number of SMD soldering tutorials on Youtube that'll teach you tricks such as desoldering a 2-pad component (resistors, etc)in one move.

 

[foulmist]

has anyone tested those drivers they look pretty sweet

i have but all I got was 600mA @ 3V
nothing special really

i tried with both lithium and alkaline batteries, at a single AA battery I couldn't even get 300mA ??? ?? wth :wtf:this driver is no good for higher current!

good for low currents though

and yes I have tried lower resistors

 

[LaZeRz]

By changing the resistor and the schottcky you should be able to get up to 2 amps of current.

EDIT:

spelling error required*