Questin about MC-E emitter..

[Starflex]

Hello!
I have read some post about this led...but I have a doubt: some people report a draw of 1,8A, some others a draw of 2,6 A.

I don't have understand if the higher current depend by the type of cell (for example, 1,8A from a 3,6V fully charged Li-Ion cell and 2,6A from a fully charged 4,2V Li-Ion cell) ...so, in your opinion, is better to drive the led with a 3,6V or 4,2V cell (of course, 3,6V is the tension reached by a 3,0V Li-Ion cell) ?

 

[DM51]

I'll move this to the LED section, where discussions about emitters belong.

 

[yellow]

very easy: DONT DIRECT DRIVE IT!


in theory: the max current of an emitter die is about 800 mA,
so a quad die should get 4 times if this to give the theoretical output.
Makes 3.2 A, right?
Thats a power no single cell can give + there are variations in each die/led also, thats why You read those different data ...

single cell + parallel wired quad led + direct drive --> problems + low output You have already read about


The only "good" way to drive it, is wired in series + a step-up driver + 7.2 V pack (2 Li-Ion cells),
but that is only my point of view.

 

[old4570]

My guess - Cheap drivers ..

 

[Starflex]

@Yellow: I think it could be a resonable idea... but I want put the MC-E in a 26mm flashlight (like the cheap ultrafire 502B)..and I haven't found a led that I can drive with 7,2 volts or more...
On DX the only one (26,5mm) is suitable for 2,7-4,2V; there isn't the parts to made it: I can buy single led, the circuit board, but there isn't the reflector, for example...

 

[zzonbi]

the current depends on battery type, and on the given led and its temperature too.
trying to control the current with resistors or driver boards is easier, but if you must direct drive the lower voltage batteries are safer. if you can comfortably touch the heatsink the led is probably ok.

 

[bretti_kivi]

you can't buy all the parts from one source.

Try heatsink from britelumens, a taskled driver and a sandwichshoppe reflector.

I will be running 2 of these (just as soon as I drill the holes in the heatsink for the 4-series wiring) in a couple of mags.
Write up will follow later. Definitely voltage not current based, or most drivers will not work with it; 500mA @ 13.2V is around 1.3A @ 7.2V input, losses taken into account.

Bret

 

[old4570]

@Yellow: I think it could be a resonable idea... but I want put the MC-E in a 26mm flashlight (like the cheap ultrafire 502B)..and I haven't found a led that I can drive with 7,2 volts or more...
On DX the only one (26,5mm) is suitable for 2,7-4,2V; there isn't the parts to made it: I can buy single led, the circuit board, but there isn't the reflector, for example...

ProductId=1845 over @ KD , this is the driver I use in my MC-E DX drop in , it gives up to 1.8A on fresh RCR123A 3.7v [ 4.2 fully charged ] and about 2.2A on a 18650 ...

Im still looking at the multi mode drivers out there , but not very much to chose from at this sort of level ATM .