I have a Dorcy 41-4297 flashlight (body). It used to have a K2 Luxeon led sitting in it, but thanks to my butter fingers it is no more, so I popped out the pcb that contained the LED.
The above link shows the light fully assembled and its tech specs, plus you can mouse over some of the pics to see the emitter and other features.
I have since ordered a Cree XR-E Q5 star to replace the Luxeon, but I wonder about the flashlight's capability to handle such an LED. You see, the weird thing I discovered is that this flashlight appeared to run without a constant current driver. The pcb which contained the LED had nothing on it except for positive and negative contact points for the 3AAA battery holder and flashlight body, respectively.
Below are images of the PCB so you can see what I am talking about.
I have seen very few discussions about this particular flashlight, even less about its internals. The tailcap appears strange, and I never was a fan of the color-change battery indicator boot. I wonder if circuitry intended for the LED is housed there, but to me it seems unlikely.
Tailcap:
So right now my plan is to get the star when it eventually arrives from DX and thermal epoxy it to a brass heatsink (basically a washer). I will then solder wires from the star to some contact point of my own creation (on the bottom of the star) for + (the center hole in the brass washer will allow for the battery cartridge to make contact with such a point), and send another wire to contact the body of the light for -, along this little ledge here (which seems how neg contact used to be achieved)).
aforementioned "Ledge" upon which pcb once sat:
makeshift brass heatsink sitting in ledge, note center hole for + contact:
My main concern is the circuitry (if any) in that tailcap, which appears difficult to take apart without damaging it. I wonder if it will impede or assist the proper functioning of the Cree led.
I'd say that the chances of the tailcap containing a driver are slim, so the led will most likely be direct-driven. If this is so, I wonder what my output and runtime characteristics will be on 3AAA batteries.
Anyway, I thought I'd submit my plans for hacking on this light to the hive, so please offer your criticisms and/or suggestions.