I finally got an emisar D4 with XPG2, and dedomed the emitters in warm gas. With a charged VTC5A I measured 30kcd at 15s. That is with stock springs. I really like the beam with the dedomed XPG2s.
I learned from bypassing the springs in the D1S that it is a real challenge to keep the spring assembly short enough to not crush the cell. I really appreciate the design of these lights keeping the size as small as possible, but it does make some modding more difficult. Anyway, I figure the stock springs are relatively low resistance.
There’s not much to be gained by bypassing Emisar springs. They were chosen to make that less relevant, by being low-resistance and compressing pretty much flat during use.
Don’t forget you are talking to a forum of powerhungry flashlight enthusiasts. :laughing: These springs have about 8 mOhms each. Cutting out nearly 16 mOhms would significantly reduce the total circuit resistance and would get some gains. But I think the design is an ok trade-off to get the smaller size.
I modded a friends S41, changed emitters to the W6 binned Samsung LH351D at 5000K, swapped the MOSFET for an Vishay-Dale SIR404DP, changed leads to 20ga Teflon coated, 22ga spring bypasses… with a new Nitecore 18350 it does 3232 lumens, on a Samsung 25S it pushes 4888 lumens!
I advised him on getting a pair of oven mitts to wear…
At a 20mV Vdroop at 6A, these springs have 3,33mOhm of resistance.
It’s absolutely amazing for a spring. Even mine are 10mOhm BeCu springs are nothing compared to them. Doing a spring bypass would just help lower resistance even further, but you will not get much in terms of % brightness boost, with a ton more heat.
Remember though Blue, all things are a matter of perspective. If it’s not JUST the spring that is being changed, it may be an open doorway to another dimension. For example, what seems like a small gain on an emitter that is maxed out, swap to an emitter that can handle double or triple the current and suddenly that small gain becomes much larger. An example would be removing the current limited XM-L2 U4 and putting an SST-40 in it’s place. Or using an SBT-70 that can gobble up 20A all by itself… same 3V supply demand.
How did you measure the springs? Pressed nearly flat against the bare pad at the center of the tail/driver PCB? If not then you may know the resistance of the springs, but you don’t understand the system.
@BlueSwordM
Yes the SBT-70 was a power drainer. Factory rating Vf 3,8V /10,5A. But could handle much more with propper cooling. And because of the round die perfect for Aspherics. I think it still has one of the nicest beam profiles in an aspheric light. I tryed to buy one when i really started with modding. But they were gone at that time.
The CBT-140 is still in the wild, big price to go with it’s big output numbers though. Probably the last round die, at least in “white”. There are SBT-70’s in green and blue.
In a Jaxman Z1, quality zoomie…
This was using a pre-focus aspheric that I built a holder for and had threaded in directly on top of the emitter.
I had also built a new solid copper pill to replace the brass one that came in the light.
Removed the glass window over the die as well, somehow I just love seeing that bridgework of 24 bond wires out in the open, in all it’s glory.
Love it so much I once took a stacked focus shot in macro to be able to see it clearly. lol
Edit: guess I have to spell it out…Pink Panda quoted me and commented on what I said, then stated “Be interested in seeing your attempt at masking Enderman”
You are right, the resistance might go down when the spring is compressed. But maybe not by much since the spring doesn’t really touch itself upon compressing and the center shouldn’t actually touch the PCB.