About 22mm. I was looking at D4v2 boost driver in it. It’s very compact, though not the most compact. The machining is excellent and I have a soft spot for Jaxman. But figure if you buy Jaxman you need to plan a driver swap before you purchase.
Here’s a comparison to some familiar friends:
I have XHP50.3 HI 90cri that I’d love for it.
I have one Jaxman. Their S2+ equivalent. E2 I think. I baked it, modded it to triple that uses 18500 tube but takes 18650 battery and has H17Fx driver.
Nice little hotrod.
Do we see a PWM in 2m distance pic? Have you tested it for PWM (stability) in various modes and batt voltages?
It couldn’t be PWM but it could be oscillations due to instability, Haukkeli can check with the Opple though we don’t know how high it can go in frequency and since there is no noise it must be higher than audible frequency if indeed there are oscillations.
I never tested it above 6A so it’s possible the compensation values are not adequate for 6.4A. The values from the suggested schematic in the datasheet for example are only good below ~4A (at 6Vout).
I’ll assemble one with the same values as Haukkeli’s and check with the scope.
Im just asking because of Lume1 project. There was no any info of instability in nicely made data sheets, but that drivers was flickering in some cases. Stability in switching drivers is important.
Very true, even if it’s not visible/audible it can decrease the efficiency.
My bet is a bad camera user fiddling with settings he fully doesn’t understand. But I can check with Opple soon.
I tested flicker from moonlight to turbo with Opple. I took maybe 7 samples. There was no flicker in any of them. Distortions in pictures could be from camera noise or flicker from led “fluorescent lamps”.
I continued with this KR1 little bit more. I swapped in XHP70.3 5700K M4 90cri and dedomed it. Now it is really neutral, duv 0,0016 and 4500K
I continued with building 12V driver for KR4. I used stencil I ordered along with boards
On the hotplate
And flashing
I had some problems with low modes. Here I did some troubleshooting.
I ended up building another one. I also used 1uH inductor this time. TheFreeman did some efficiency tests and 1uH gained 1% more efficiency compared to 1.5uH.
Then I did some output measurements. Battery voltage was ~4.14V
Input amps
Output amps
Driver in place
2 *XHP35.2 4000K 90cri +6500K 80cri +3000K 80cri. Calculated output OTF should be~3200lm.
Aux board connected
And finished. Here are 2 KR4’s. Nichia 519A 5700K dedomed with linear driver and this one. Both on lowest mode.
Here it’s alongside the KR1 I built earlier
Here are some measurements. Anduril 2 stock stepped mode step 4.
Thank you for reading this thread. These drivers will hopefully be available soon for everyone willing to build them.
Great job !
Very impressive !
I don’t understand a thing about this, but I envy these skills and knowledge!
I’m glad it entered the OL Contest as well, different stuff to widen the perspectives 
