On the K9.3 driver the sense resistor is 10mΩ and and the sense voltage is bumped to 90mV compared to 50mV in the 5A KR4/D4V2.5 driver (also with 10mΩ Rsense). I assume it’s the same for the 7.5A driver, no change to Rsense and Vsense = 75mV.
I am not sure, i will have to look at it, maybe someone can share a picture of what that should look like?
I know, i ordered these 6 weeks ago. Had i realized i was using a sft40 i would've asked for one of them to be 9amp. but then again, heat is a factor, so 7.5a might not be terrible in that small host.
hmm. this sounds interesting. would you be able to share with me what part would be needed, and where it should be soldered, to make this change? I have a feeling i get the concept of what needs to be done, because -
I feel like there is an old Matt Smith (Adventure Sport) youtube video where he mods a driver of some sort by soldering / stacking resistors onto each other to get more current? I wonder if this is the type of mod you and JaredM are referring to?
CNCman - haha! yes it is, im pretty excited. Will probably take me both days due to small obligations around the house. lol
TmaxxJJ - I know me too! I know the FET enabled KR4 driver shold pump out some amps with the Molicel P26a i will use in that KR1, I'm excited for that!
And the D1s should be good, once i can properly tune that beam! its been rough, and i've got over an hour just into reaming the reflector and swapping between different centering rings, no rings, kapton tape, etc.. If i cannot dial in the beam very well, i may try the CULPM1 in the D1s as well... but i really do not want to "throw in the towel", but that D1s reflector is being a motherf**&er to try and dial in with that SFT40.. It started out horrible, so at least I'm making progress lol..
D1s from what I remember hearing had a flawed reflector. I believe the GT mini reflector fits it however… but maybe I have that backwards.
About the sense resistor, you’ll see a relatively large resistor marked with R010 or something similar. That would mean its .010 ohms or 10 milliohms. Whatever the value is, the formula is as follows.
Sense resistance (milliohms) * current (amps) = sense voltage (millivolts)
For example
10mOhm * 7.5A = 75mV
You then use this voltage and work backwards using your desired current. Lets say you want 9 amps
75mV / 9A = 8.33mOhm
So thats your target resistance
Resistors in parallel behave such that the total is the inverse sum of the reciprocals.
So 1/0.00833 = 1/.01 + 1/x
1/x = 20.05
X = .050
So stacking an R050 on top of a R010 should yield 9A.
As I said, I may have had that backwards. D1 definitely had a bad beam, and I remember some folks swapping reflectors between D1s and GT mini. I can’t remember which was better and never had either personally.
Got a cheap triple flashlight from Alonefire. It comes with a white, warm, and UV LED. Swapped out the random white and warm LEDs with a XPL-HI 5000k and a sliced LH351D 2700k. Apologies since I can’t really manipulate white balance properly. The LH351D looks more orange IRL rather than rosy.