too bad this one is canceled. Maybe someone is going to build it anyway?
I was just thinking about how to add resistance in the D1S with 2mm^2 white flat. Is there enough clearance with the reflector for some 1 or 2W resistors in the head to the side of the MCPCB? You could attach them to the head with thermal adhesive to make sure they don’t overheat. For the 2mm white flat you need to add about 0.1 ohms to get the current down to 7A or so, so they need to dissipate between 4 and 5W.
Easy.
Just replace the BeCu spring with a regular steel spring of a similar size.
Yeah I guess that would be easier. Djozz measured steel springs to have about 50mOhms each.
Interested!
a proper thing would be a real new 1S high current buck driver
I began one with a 16A rated chip that may handle 12A fine in 20mm diameter
on the 1mm² white flat I see no big problem if he gets a proper thin low resistance inductor like Coilcraft 6030 and 4A
with the existing buck driver designs RMM, Sofirn and KD uses
someone measured the GTmini at 4.5A, does this mean the GTmini can use oslon white without any mods?
XPL-Hi will self regulate its current with DD on a safe value
the 1mm² white flat would kill itself under same conditions
No.
It’s 4.5 A with an XP-L HI.
just to clarify, hank is not building this…
But is it something that can be cobbled together by a hobbyist?
if you find a good 4A buck driver that fits yes
So Best to drop a the o`l S4 2B dedomed into the DS1 then hey
Anychance the Black flat in 2mm2 would be ok in the DS1 ??
Dave
the problem is fully charged cell dont drop that deep in voltage even at 8A or so
I put a whiteflat in my D1S.
With a full 30Q it only draws 4,9A… I guess it’s safe enough
310kCd
3.29V at 4A, no way a 30Q drops that much with high conductive springs
Lets not forget that the driver is electrically isolated from the body itself so black flat is a great led for this light if stock DD driver is used. White flat might be new and slightly better but the black flat its not “old stuff” yet 
Why the talk of a buck driver, is it necessary to lower the voltage? Limiting amperage to it I get, not catching how a buck driver would come into play.
I put a Black Flat in a little Utorch UT01 with a good 14500 cell, performs very nicely, so wouldn’t it be just as feasible to use a high capacity 18650 that can’t deliver high power… 30Q would be totally the wrong way to go with a direct drive supply….
(For the record, have already done a Black Flat 1DS and changed it back out, didn’t care for the result. Now, the Z1 with the Black Flat is a different story! As is my X5 with AHorton aspheric…)
If you add resistance with a fet driver you can set the best current for only one voltage level. If you set resistance with full battery when battery depletes the current will fall and output also. If you put in a slightly better battery it will give more amps to led. If you put in a GA cell it will give lower current. But a buck driver can make constant current for the led and no matter what battery you put in the led can’t get too much current, and if voltage dropping it can get more amps from battery to keep the same current at led. Simply it can keep more stable output.
Is there an option to get an 5000k 70CRI SST-20 in the Emisar D1S?
Having a 2mm2 sized die, it would give us quite a bit more throw coming stock, and would easily handle a FET driver.
We could even dedome it if we wish for even higher throw.
But so can a linear CC driver.
Sure, a buck driver is very nice and efficient, but it also has a larger minimum voltage drop than a linear CC driver like the ones from led4power or the LD25.