Downboy questions for project

[AlexGT]

I have 2 downboy circuits rated at 1500ma each and would like to know if I could solder a trim pot instead of the resistors (Which one?) to have a variable brightness and efficient driver for a diamond dragon led.

I want to be able to adjust the brightness from low to a high of about 2 amps. So I might want to wire the downboys in parallel.

How should I do this?

Any ideas?

Thanks!

AlexGT

Here is the pic of the Downboy with the 2 resistors one at .05 and the other at .10

 

[Der Wichtel]

You have to figure out where the feedback pin of the IC is. Then you can add a pot and two resistors.
However it won't be easy since you have to cut the fb trace and add the pot between that trace.

 

[AlexGT]

I was thinking of an adjustable trimpot (Potentiometer?) as Darkzero did on his Mobydick flashlight

What I was going to try was unsolder the resistors and wire the contacts to the trimpot and have a variable resistance across them.

AlexGT

 

[Der Wichtel]

the resistors should have less than 1ohm because they are current sense resistors.

It will be difficult to find a pot whithin that range ( 0-1 Ohm) furthermore it must be able to handle the current.
If you find one, then just replace one of the resistor with the pot

 

[darkzero]

I was thinking of an adjustable trimpot (Potentiometer?) as Darkzero did on his Mobydick flashlight

Nope, not me. I think you are referring to LEDZepplin?

 

[AlexGT]

Opsss! Thanks for the clarification!

AlexGT

 

[nailbender]

Hey Alex

I am sure you would rather use what you have but what about a 2 amp shark with a remora. Wayne sells these at the shop.

Dave

 

[AlexGT]

Thanks for the tip Dave, I was trying to find use for these drivers before I decide to sell them.

Do you know if the Sharkbuck 2A can take 2 Li-ions in series to drive 1 Cree or Diamond Dragon led at 2 amps regulated?

Do you know the drive current for Low and medium on the remora circuit board?


Thanks!
AlexGT

 

[nailbender]

Hi Alex
yes you can use two li ions with the sharks, most of that is covered at the shoppe. I am not sure of what the levels are of the remora. Led Zeppelin probably could.

sorry for the late reply. Problems with DSL

dave