My Copper (is it really brass?)pill KD C8 was pulling 4Amp stock, and I added copper braid on both springs…
and now it is pulling 5.3Amp on high. :~
Medium is now pulling 3Amp.
On high it gets hot very fast. I compared it with ultrafire C8 pulling 3Amp on high and well its just like the KD C8 medium.
Thing is, I was wondering if the KD is not just wasting 1 Amp in heat? I have no way of measuring the actual light output.
You may be pushing it a little bit too far if the pill and PCB are not copper.
Which driver are you using, a direct drive or a stacked AMC7135?
Above 3.0A is the point of diminishing returns so you may not getting much brightness improvement as much as heat generated.
Here’s a brass vs copper shot, brass has a yellow tint whereas copper has an orange tint.
Keep going!
Haha. I drive my KD xml2-u2 on sinkpad over 6 amps.
Fried a switch today though.
Opps!
Chris
I guess the pill is brass, more yellow than red metal.
No idea what driver is used, as it is a stock C8 xml. I compared it to a KD C8 on xml2 and it was a bit brighter than the xml2. That was before the spring mod!
I appreciate that there is absolutely no PWM whine on any mode. If I knew what driver KD is using on this one, I would probably try to put one xml2-u2 on copper star with fat wires from driver to the pill. pretty sure it will be able to pull 6Amp.
At 5Amp it’s hot after 30 seconds. I read that if its too hot the led would be dimmer so @6Amp… will it be brighter or dimmer?
The XML is rated for 3A maximum. What you have done is found the least efficient way to convert electricity to heat.
Rated yes maybe… but it is sure brighter 5Amp than the other one
3Amp. So I am not wasting ALL of the 2 Amp into heat. A lot of waste for sure, but not all.
What I am not sure is whether it is/was brighter/same @4Amp.
The LED may be running very hot, possibly overheating and dimming. Of course, that would be hard to measure without a lux meter.
If you have a smartphone, you can use the built in lux meter to see how much the brightness decreases from the time you turn it on due to overheating and sag.
If you want the most out of your light at 5-6A, swap the PCB into a copper Sinkpad/Noctigon as well as the pill for maximum heat transfer.
Here’s match’s test results:
There’s a chart floating around here somewhere, you start getting diminishing returns after I believe 3 amps, but you will see a worthwhile increase between 3-5 amps imo. Beyond that you start getting into short lasting LED and extreme amounts of excess heat. Above 6 and you’re just asking for and spontaneous combustion of anything in the path of the light emitting from the soon to be dead LED, a melted flashlight, and blown LEDs.
I see no problem in it as I guess with decreasing battery voltage the current also decreases anyway. You have basically a turbo mode and the mid mod is high mode…
But as others have wrote I would recommend a copper sinkpad/noctigon for best performance. I don’t use alustars for lights above 2A anymore.
Anyway the 5Amp is tail current, not at emitter. So I assume that there is loss at the switch and driver. Anyone have a guess how much loss approx?
“I don’t use copper stars for lights above 2A anymore”…….?”
the links to the app to use the smartphone? app
There are good and bad ones, but I’m using an Android app called the Physics Toolbox for my Nexus 4.
Here’s the thread about it:
I think there are good iOS ones as well.
If you had a light meter set up to check lumens I would bet that you will see the lumens drop off quickly. Probably starting at 1250 or so and quickly down to 900 you would be able to watch as it takes a nosedive. This is from thermal sag. Copper stars and good heatsinking will keep the lumens higher longer. The fact that you haven’t fried the emitter tells me you are getting some loss from resistance to begin with, buck driver or thin wires take your pick. Depending on what kind of batteries you are using you could be getting some battery sag as well. Probably all a good thing or it would have gone a nice shade of blue and then stopped working completely. My advice would be to buy a couple noctigons from international outdoors. Either reflow your emitter or just buy complete new ones. In the meantime use your high as a turbo mode only. While you have it apart you can always de-dome the emitter if you want more throw and a more neutral color.
Good luck and have fun.
Would the app work properly on it?
I’m sure it would be able to provide lux measurements, but phones have different max input values.
The Nexus 4 goes up to a generous 10,000 lux, but not sure about the S4.