^ Good point. Since that TN31 driver is also voltage limited (on output), maybe the higher Vf of the XM-L2 was restricting current.
I will check that out when I go into the light next time. Might be this weekend.
I can say the 219C with it's dome created a nice beam profile and tint. Throw was not stellar. It measured some where around 150 - 160kcd (I think it was 156), but I didn't put any effort into focus. Just wanted to get a general feel for what it would do.
That shows the 219C really has low enough forward voltage to get as much current as one wants with one cell. Time to stack more 7135s on a Q Lite. Direct drive turbo is for Crees!
It sounds like the 219C should do okay with a FET as long as it only uses low-amp cells like the NCR18650A. I think. Does this sound right?
I want to put one in my CNQG brass 18650, but it only has room for a single-sided driver… so that means 4x7135 or a FET+1. Does a FET+1 and NCR18650A sound like a safe combination?
With DD drivers extra voltage is burned off in LED,since DD is just low resistance switch;with linear drivers extra voltage is burned off in driver itself.
Excellent work, btw! From the beamshot earlier you posted, looks like the 219C doesn't tint shift much when de-domed.
Is this the same one you reported earlier with the SS collar? It sounds like it would do the same on a KK cell. I can fit the KK 26700 cells in my 1405's - the 26700's have high capacity and pretty good low resistance.
What's the SS collar? I recall discussions - can't recall if it helped much. I tested one hand made by O-L way back but didn't get any noticeable improvements.
Should end up at around 1240 emitter lumens, according to the chart. Close to the maximum but, more importantly, on the left side of the output curve. So I think the main remaining issue then would be heat, with is a bit easier to deal with. I may even use this as a testbed for thermal step-down features on an attiny25. In such a small driver cavity, the MCU should have a relatively easy time sensing the pill temperature, especially if I cram in a thin piece of thermal-conducting foam.
I reflowed 3 of these on a (slightly well used) triple board. I will see this evening how much they draw from a FET driver and a 25R
Ok, I measured the triple at 12,8A with a fully charged 25R and at 10,8A with a fully charged 18500 IMR Efest.
I’d expect an Efest Purple or LG HE-4, Samsung 30Q, to do higher than 12.8A. Hence my 15A wager…
Still, very impressive lot of output in a High CRI rendition, no doubt! :bigsmile:
Edit: Assuming you did spring bypasses, right? Through board on the switch? What size wires did you use? I’ve taken to using 18ga for these projects to allow every possible bit of current to flow. 16 ga if I can fit it in.