This is also weird. While testing, in a higher mode, think turbo, I heard/felt a 'pop' coming from the head which I really thought was the LED blowing the silicon bubble, but instead, the blue tint shift went away! It still gets hot quickly on turbo, but the tint shift issue is no longer. Didn't notice any physical damage to the LED either. Wonder if maybe it wasn't reflowed properly, then the heat melted the solder some what and re-seated the LED better on the pads. A bad reflow can cause the tint shift, from what I thought.
Even though in the initial use of the flashlight I didn't notice any angry blue, this evening after turning it on I indeed saw that the tint turned blue after staying for a couple of seconds in Turbo.
So TomE , it seems that there is something clearly wrong in the flashlight in general.
I shall send a message to Fomolov to let them know about the issue.
Did'n't check specs, but yes, seems like the 219D is low Vf LED, so amps can go crazy. That pic I took of the tail PCB certainly appears to be everything a fully working driver needs - I'm assuming that is a full driver, and at the head, is probably something simple like a resistor or something, no smarts. Got a couple of 18650S owners over on FB (Flashoholics Anonymous group) saying they don't see the blue shift on turbo on full charge, but mine is not showing that now as well. May have to risk an attempt to get the head apart.
Out of the box quite nice. Great fit and finish and nice compact size. No sign of blue-shifting tint when I used the partially charged cell that came with the light.
But then I used the built-in USB to fully charge the folomov cell and PROBLEM!!! When turned on in turbo the light blue-shifts within 5 seconds and output drops dramatically. Instead of 800 lumens it looks like its only outputting 100 lumens.
Once the light is warmed up by having been turned on and off for 5-10 seconds, the problem is worse. Turning the light on while it is warm causes the blue shift and reduction in lumens to happen almost instantly (less than 2 seconds).
and all of this is with the cell that came with the light! It’s not even a high discharge cell I assume.
My guess is the LED simply can’t take the amps. Either that or the LED is defectively installed. If anyone can get the head open it might be worth swapping the LED to something else. Perhaps XPL HI.
The most interesting thing about this light seems to be its tail-mounted driver with no extra channel to run BAT+ back or run the switch signal forward.
How does that work? Does it seem like something which might be useful for BLF designs?
I agree. I’d LOVE it if someone made a tail mounted e-switch driver that didn’t need the extra channel and sold it on Mountain Electronics. :heart_eyes: :heart_eyes: :heart_eyes:
I agree - it's fairly unique, but I think the UltaFire UF10 had the same design. Here's the UF10 driver from the tail:
I really like the UF10, same sort of tail e-switch, but much simpler UI. All I did was swap the LED/MCPCB,and maybe wires to get more output and added bypasses.We use it about every night with the dog.
Ohh, this is the PCB at the head, so there are some surface mounts but no smarts, I believe:
This info is disheartening.
I ordered one which will arrive tomorrow after the all clear was given.
Maybe I’ll get lucky with my sample but Not going to keep a flashlight that can’t be dis assembled to fix.
How does the flashlight operate with other cells?
Thanks
Actually, I think the fully-charged cell might be providing too much voltage to the LED.
After running the light another couple minutes on and off I notice that it no longer seems to blue-shift and dim. So the issue seems to occur with the fully charged cell.
Anyone figured out how to change the LED in the 18650s yet? From looking in the back of the head it looks like a press-fit plastic washer might be keeping the guts of the light in place.
Well, that's not press fit plastic. It's a black painted LED isolator glued to, what I think, is a shelf. I got the isolator ring off and it exposes threaded screw holes with screws in them from the top. Only way they could do that if the front end bezel comes off - suspect it's glued,very hard to see where.
Nothing magic done there. If the driver is completely in the tailcap it can work. think about that way that the tube is the led negative wire. The led positive is directly connected to batt+ and that is all. So the head only have a contact PCB which connects batt+ to led+ and tube to led-.the circuit is the same just the driver location changed in the light. The only drawback I see that is not good for high power lights because you can’t measure heat at led. If thermal sensor is in the controller it takes a lot of time to sense the heat. The only working option is timed stepdown. I hope I soon get mine and make an X-ray photo from head to see if there is any parts in there other than only a PCB.
