First I ordered boards. I ordered them from Aisler this time. Next I ordered components from Mouser. Component shortage made things more difficult than they needed to be.
I searched many alternative parts and in the end TheFreeman sent me few low resistance mosfets from his personal stash with Attiny 1616 programmer.
When I had everything at hand it was time for assembly. I first build 6V 6A version for KR1. And here it is, straight from the hotplate:
Next phase was flashing the MCU. TheFreeman had modified the Anduril 2 code I think previously made for HDR linear driver.
I used AVRDudess and programmer TheFreeman also provided. I could have made one by myself, but this way it was easier.
First version of the firmware had some bugs, that were quickly smoothed out.
Next I did some testing.
I soldered wires to the ground ring and spring pad. I also added switch for ease of testing the driver and of course the led wires.
Notice that the driver has additional 5060 P-Fet capability on the backside for even better efficiency and pads for aux and switch lights. I plan to install that P-Fet next.
I dismantled KR1, added switch spring to the new driver. Then I decided to take some comparison photos of drivers.
And all together
Keen eyed viewers might have noticed that Noctigon/Emisar driver uses 50mOhm sense resistor. So it causes ~0.1V voltage loss in sensing stage. My earlier boost driver from Intl.Outdoor had 20mOhm one.
To be continued…
Here I took some Opple readings.
First stepped mode stock step 4
Then turbo
This led has very neutral tint for whole output range. DUV 0.0029. Beam is very pure white. It seems to sustain top of the ramp easily. If checked from XHP70.3 datasheet it corresponds to about 1000 lumens after reflector and lens losses. Not bad for 90cri led in small flashlight(led bin: 2D M2 90cri). Turbo output corresponds to little over 4000 lumens after losses.
Here’s still one photo of the lowest mode.
Next I planned to took some beamshots and maybe compare moonlight modes of different flashlights.
Quick moonlight comparison between this KR1 and Convoy M21B. Both in lowest mode and both using a boost driver of similar max output. Both also have same led.
Some piping in darkish enviroment ~20m away.
Control photo
Turbo
That’s it for now. I’m happy with this build. Only con of this light is the capacity of 18650. This driver will allow me to use every drop of it.
I suggest everyone to read TheFreeman’s driver thread. He’s closing the point of making these public. Still some UI things to solve. Anyone with skills in that regard is welcome to offer some help for him.
I will continue in near future with KR4 and 12V build.
Very nice to see the first of my HDR boost drivers assembled and used by someone other than me , Haukkeli was very motivated to go through the whole process and he provided valuable feedback, he’s a great beta tester :+1: .
In this configuration (6.4A6V) the lowest mode is ~75uA, for comparison the lowest output (li-ion) Zebralight is the SC700D at 50uA (6V), with some tweaks it can go lower but I think this is low enough.
That light looks pretty good, what driver size is that though ? it looks very small for a 26650 light.
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.