Will these work like MJLEDs? Help me wwglen?

cratz2

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Well, they may be useful and may make you happy, but they almost certainly won't be as bright as the MJLEDs on two cells. One of the reasons, if not the reason, the MJLEDs are/were so popular is because they have a lower forward voltage so they work very well on two alkaline, NiMH or Lithium cells though some report early failure with Lithiums.

The Sandwhich Shoppe has non-cutdown LEDs for like $3.00 each which are likely the same thing as the MJLEDs. Or for a cheaper option if bought in bulk, the 35k LEDs from KevinL work pretty well on 2 cells, even better on three and are only like $1.00 each.
 

cratz2

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Well, the Shoppe is a very reputable dealer so if they say they are the same, I take their word for it. I was under the impression they are the same as the MJLEDs but they aren't cut/sanded down. This means that unless modified, they ones from the Shoppe should throw more light forward but with a less smooth beam than the cut down MJLEDs. The MJLEDs are cut down so the reflector can catch more of the emitted light and direct it forward resulting in a more traditional beam.

There are several posts on how to modify the non-cutdown LEDs into the cutdown ones. I'll search and see what I come up with.
 

jbrams

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I found these (second LED down, not the top LED) on a canadian website for $1.25 plus $5 shipping CAD ... I figure that buying a few at $1.25 then modifying them myself would get me some very cheap MJLEDs ... BUT:

(1) Are these similar enough, or will they work like MJLEDs? (i.e., the specs seem the same, but am I missing something?) Specs:
10,000 mcd
5mm LED
Voltage: 3.4~3.9V
Current:
Normal: 30~50 mA DC

Peak: 100 mA (pulse)

Angle: 15~30 degree

(2) How should they be modified to become some kind of "homemade MJLED"? I see a thread on this by wwglen, but I'm missing the details on what needs to be done to change the LED physically (other than cutting the leads) ... grind/sand them polish it? How should it be changed (flattened top? Soemthing else?). A close up of a MJLED might be helpful here if anyone has such an image.

(3) Would these LEDs be more appropriate?:Emitting Color: White
Size or Style: 5mm
MCD: 22000 Mcd
Type: TS UB 4die
Voltage: 3.5vdc
Current Draw: 100
Viewing Angle: 25 deg
Part #: 5m100w


Thanks!
Abe
 
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balazer

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The MJLED is rated at 100 mA constant, 150 mA peak. It's been show to maintain lumens pretty well at 70 or 80 mA. The LED you're looking at is not very similar.
 

jbrams

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balazer said:
The MJLED is rated at 100 mA constant, 150 mA peak. It's been show to maintain lumens pretty well at 70 or 80 mA. The LED you're looking at is not very similar.
Well, that's that I suppose.

In that case, where can MJLEDs be had for cheap ($5?) without high shipping costs? I've seen lambda's (sp?) site but he seems to be out of stock. Any suggestions? Also willing to trty nite-ize but walmart is not nearby or, well, a company I want to support if I don't have to.

Thanks,
Abe
 

jbrams

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cratz2 said:
The Sandwhich Shoppe has non-cutdown LEDs for like $3.00 each which are likely the same thing as the MJLEDs. Or for a cheaper option if bought in bulk, the 35k LEDs from KevinL work pretty well on 2 cells, even better on three and are only like $1.00 each.
Are the Sandwhich shoppe LEDs really the same thing as MJLEDs? If they are different (I'm guessing they are) then how are they different and is it possible to change them to better emulate the MJLED (and if so, how)?

Thanks for the fast replies!
 

LEDninja

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Uncut MJLED from the shoppe. Very weak hotspot, slightly more spill light. Almost a weak flood with a slightly brighter center..
http://theledguy.chainreactionweb.com/product_info.php?products_id=578

Cut MJLED from Lighthound. Strong hotspot, spill light a little less bright. More traditional flashlight beam pattern.
http://www.lighthound.com/sales/mag_flashlight_accessories.php

Beam pattern descriptions are for minimag. I was able to get a pretty good hotspot in an Energizer flashlight/lantern with a great big reflector. with the uncut MJLED that I removed from my minimag.
 
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