M21C with XHP35 driver and FC40 is great
I would buy one definitely, too.
Just buy.
All items are in Convoy Store :)
I just think the 2.3A current is a bit small. Of course, if you like this configuration, I will add a link soon.
Hello Simon,
if you think about raising driver current specifically for this host + led combination, I think, 3A would be the best setting (keeping in mind, that this host is smaller than L6 and L21A).
I have it already but i was telling MoreLumens that components are allready available at your store
I agree, XHP35 driver upgraded to 3-3.5A wiuld be great in M21C
Anything change with the XHP35 to run at higher amps? From this old test here, it peaks at ~2.5 amps: https://budgetlightforum.com/t/-/43473, and at 3.5 amps output starts turning blue.
We are thinking to pair this driver with FC40...
Oops, yeah I see. Depends if parts/design have to, and can, be changed to run at higher amps
I think it's possible. M21C driver cavity can accommodate even bigger components than they are now on present drivers.
Clearance will help for a bigger coil, and depends. For example on the original BLF GT buck driver DEL designed, he had designed in more amp capability, think ~5 amps or so, if I recall.Of course there was plenty of room on that driver in that light.
Can someone to tell me what is the driver diameter of new S21B. It is 22mm? From Simon store I saw that XHP50.2 version used the new 3A boost driver which is 22mm. Also now we also have very good buck driver for 3V in 22mm so we have nice S21B host for new switching drivers from Convoy, if it used 22mm drivers.
It is 22mm.
Thanks.
Can’t wait to mod my L6 with FC-40 and a 4A driver, Simon please make it happen
Anything change? 
To be more precise, since output data was collected each 0.25A, we need to analyze previous and subsequent data:
- 2.25A: 2500 lemmings
- 2.50A: 2570.
- 2.75A: 2580.
- 3.00A: 2530.
Peak was somewhere between 2.5 and 2.75A. Since 2.25A shows a lower value than 3A, we can infer that the peak was closer to 2.75 than to 2.5A, probably at ≈2.66A.
Test data shows that at 2A output was already above 92% (2380/2580) of the measured peak, and 96.9% at 2.25A. In my opinion, 2.1A is already hot enough (close to 94%), imho. There's simply not enough XHP35 test data, just (!) one test. For a driver which must be paired with all sorts of XHP35 emitters, I think it is wiser not to go overboard. Not all emitters peak the same, check SST-20 tests for example: 6500K (peaked at ≈6.75A), 4000K (peaked and died at 7A?), 3000K (peaked at ≈6.15A).
One more data point, Koef3 with his more powerful cooling setup observed a peak at 3.2A:
But I agree, 2A is enough and 2.1 is even more so. I’d go with no more than 2.25 and even that only as a Turbo mode or in a huge host.
Gents don’t forget we’re asking Simon for Amp increase for use with FC40 emitter.
Present 2.5A driver is more than enough for tiny XHP35