I apologize for the confusing wording in that thread. I was trying to relate that I know what a 7135 is and generally how it works. My goal was to add a chip with similar functionality to the driver. It worked but was horribly inefficient. I swapped the capacitor opposite the inductor with a 1uF (no idea what value was there already) and it seemed to increase runtime with no noticeable drop in output. If I recall correctly my light, with my eneloops, went from ~90 minutes to ~120 minutes before it was too dim to be useful.
After several days of reading about boost drivers my head hurt a lot. I came to the conclusion that the only real way to mod them is to replace the various components. Unfortunately, all the variables seem to interrelate. Without knowing the specs for that central chip it’s a guessing game.
I have variety of inductors coming so that I can swap them out and see how it changes output vs runtime.
Has anyone measured tail cap current on the cell types? Given that it survives 10440 it might be an ok driver for 2 X AA. What is current draw with 10440@ 3V?
What the PAM2803 has is not what we’d normally refer to as temperature regulation. It has “Over Temperature Protection” which kicks in at 150c. The recommended operating temp range is –40c to +125c junction temp and an absolute maximum ambient temp of +85c. What you are seeing is not the chip proactively trying to reduce the temperature, it’s the chip reactively trying to prevent an outright failure while already operating above the absolute maximum temperature. The reason that it goes back and forth slowly rather than flickering is due to the 15c hysteresis. “Over Temperature Protection” should trip at 150c and not un-trip until 135c due to the hysteresis. The datasheet isn’t the be-all and end-all, maybe it will survive forever like that. My intention with the above is simply to help you better understand what the datasheet says.
See above RE: “survives”. That said, I think that 2xAA or 2xAAA will be fine. After quickly examining the pics over in this thread: Фонарик BLF 348 Nichia NVSW219BT - V1 (post#11 by MSS) we see that the driver is using a 0.5ohm sense resistor. That’s perfectly reasonable (about 0.19A output - exactly as one might expect with the output measurements). While the driver may be unregulated for part of the discharge, the amperage should not be high enough to cause any temperature problems. Swapping in a smaller sense resistor could help maintain regulation (more boost).
Any possibility of a new group buy? I would definitely buy a couple or three. I did post a WTB in the forum if anyone has an extra they’d like to sell!
hey dude @mhanlen… you are a bad influence on my wallet… as your reviews made me buy the noctigon m43 and just recently the emisar d4Ti (3pcs)… hahahahaha
BLF-348 is available again in GearBest, but now it’s using the Nichia 219C instead of 219B.
(I wonder if the 219C used in the recent batch is 90 CRI or not?)
What I’d like to ask is if the lumens of the current batch using 219C would be the same as the older series which use 219B?
(I understand that 219C is brighter than the 219B, but when using an Eneloop AAA and assuming the tailcap current is 0.8A or 1.10A, what is the expected OTF lumens of the 219C?)
According to the description, it claims to be the same one we had multiple group buys for. If that’s true, then it is the good version. I’m not 100% sure we can trust Gearbest. I haven’t heard of any fakes from them recently, but they’ve definitely done a lot of fakes in the past. If you decide to buy one, how about testing it out really thoroughly for us and letting us know if it’s a “good” one or not? There are many of us that would still like to buy some more. :innocent:
I bought some of the SingFire lights, and a couple of the BLF with Nichea. I found that I preferred the SingFire to the BLF Nichea.
I d on’t spend any time comparing beam colors.
Except for the increased price I prefer the Hugxby Xp1.
Jerry
What are the reasons why many of you want to buy them?