What did you mod today?

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! :smiley:

I advised him on getting a pair of oven mitts to wear…

It’s not 8mOhms, it’s even lower.

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.

I measured close to 50mV at 6A, but maybe there was an error.

I don’t know how to do those measurements, but I personally would be more interested in 16-20A instead of 6A. :wink:

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.

An SBT70 can gobble up 20A at 3V?!

I only thought the CFT-90 could go up these insane currents at low voltages.

Also, that 6A is just a reference figure. And yeah, if you are pushing suddenly 18-20A, that 20mV becomes 60+mV.

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.

I tested few springs a while ago by using accurate 4-wire method, including IO short spring, and its resistance was 7,4mOhm :

https://budgetlightforum.com/t/-/46929/201

@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.

Yeh, I wish their were more alternatives with a round die :heart_eyes:

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. :wink:

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. :smiley:

Love it so much I once took a stacked focus shot in macro to be able to see it clearly. :smiley: lol

That looks amazing :slight_smile:
Love the CBT140.
I still haven’t tried my method of making round LEDs by masking the top.

yeh, at that price it can stay as elusive as a unicorn :confounded:

Be interested in seeing your attempt at masking Enderman :nerd_face:

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.

The body tube on my D4s is ~70mm. My cell is 65mm long. That leaves 2.5mm for each spring. The spring wire is 1mm in diameter. I have a few extra Emisar springs I bought. When compressed to 2.5mm the electrical path isn’t the full spring length. There is contact between coils and it looks like there is more than one loop in contact at the battery end. It is a little hard to estimate the shortest path, though.

It looks to me like some tweaking the roundness and/or alignment of the coils could actually lead to better contact, by forcing the coils to slip against eachother as they are compressed and/or tipping a bit so that there are additional contacts and paths between spring, battery, and pcb.

Let the Build begin. :beer: Planning stage has ended. :beer:
This will be a 3 step project. Had to protect the head with some quilting batting and painters tape.

Tool is finnished so i do not scratch the head, lether cushions for the vise are glued together and cured and the new driver (from Lexel) is ready. So time to pop the H03 open. Have to get the heatgun ready first but then nothing will stop me. Wish me luck. Hope to get it open without doing any damage to the threads. Switch rubber and front glass/tir are removed. Tube is filled with a 19,5mm pipe to prevent it from squashing. I think there is nothing else i can do to prevent failure.


For the record, I have seen heavily glued threads remove the aluminum thread from a light leaving it stripped and impossible to reassemble, even with the use of a torch. Just saying… approach it carefully and take your time…

Good luck!

Oh, and watch for that to roll off to one side, careful not to scar up the head…

Edit… and watch for the tube to want to spin in the pads on your vice, the knurling may try to eat the leather and then get eaten by the vice. (Yes, I’ve seen a lot of things happen …)