Novice question to modify Dorcy 3D flashlight

[Cpt999]

Hi,

I am a complete novice in terms of modifying LED flashlight. I have an older Dorcy 3D LED flashlight (1 or 1.5W) from Target and I am thinking of making it brighter. The emitter module seems to be easy to de-solder and replace. Which brighter LED should I get and what else needs to be done (such as removing/replacing a series resistor etc.)? I looked at the DX site and found that two parts seems to match the shape of the original emitter:
(1) SSC Seoul P4 (U-bin) SW0 Bare Emitter
(2) Luxeon Lumiled 3W 700mA LED Emitter (LXHL-PW09)

Which one should I get to replace the original? Thanks very much in advance.

 

[DonShock]

The Seoul P4 would be the simpler mod. A straight swap would give you more brightness at the same current as the existing Lux1 LED. The Lux3 would work also, but you would probably need to change the resistor in the Dorcy to increase the current up to the 700-1000 ma where it is the brightest. Of course, your brightest result would be to do both, use the Seoul P4 AND change the resistor to increase the current.

 

[Walt175]

I put a Seoul P4 into mine, and it works well. My only complaint is that I have a doughnut hole out to about 3 feet. I need to make a shim to raise the height of the star to focus it better.

 

[Cpt999]

Thank you for the replies. I have not unscrewed the small circular PCB yet. I guess the series resistor is on the other side of it. I will go ahead and order the Seoul LED and try it.
I think you can twist the head to focus the light, though the pattern is not that great.

 

[Cpt999]

A quick question: could you tell me the current of the original Lux 1 LED? I would like to get some idea of what new resistor value is needed to increase the brightness. Thanks.

The Seoul P4 would be the simpler mod. A straight swap would give you more brightness at the same current as the existing Lux1 LED. The Lux3 would work also, but you would probably need to change the resistor in the Dorcy to increase the current up to the 700-1000 ma where it is the brightest. Of course, your brightest result would be to do both, use the Seoul P4 AND change the resistor to increase the current.

 

[DonShock]

Yes, just unscrew the retaining ring to access the current limiting resistor underneath. The star is on a flat board underneath the retaining ring and it will drop right out once the ring is removed. And I haven't measured the actual current to the LED on the Dorcy, but the rated current for a Lux1 is 350ma. IIRC, the first Lux3s were rated at 700ma and it was later raised to 1000ma. I have always run my Lux3s at 1000ma with no problem. But the hatsinking in the Dorcy is pretty poor so you might want to keep the current down a little. I haven't done any work with the Seoul P4s, but I think 1000ma is the max current on those too.

 

[Cpt999]

Looking at the DX site again and I saw the same Seoul P4 being sold on a star board, which is same as the one in the flashlight. So I guess I can also order that and it will be easier to replace the whole star board? However,there seems to be some quality issue with that star board version.

 

[tkflash1]

Hey all! Just wanted to mention that to raise the emitter for a seoul upgrade you don't need a copper shim under the star on the Dorcy light. Just remove the star and sub assembly and remove the black plastic spacer under it and add a thin piece of plastic or cardboard about the thickness of what you need between switch assembly and the black plastic spacer. It is easy to cut out with scissors to fit around the wire. Then reassemble. To find the thickness you need play with the reflector. This helps get the correct focus with the stock emitter too if it isnt correct. Those black spacers are not all the same thickness from the factory. I have several of these lights and they are all different. Tom