*BLF LT1 Lantern Project) (updated Nov,17,2020)

Looks great. Lets get this thing produced

Nice video DBSAR, i’m not bothered with your sniffles but sometimes you are speaking a little to fast for a foreigner like me but I was able to understand 99% of what you were saying (I know it’s difficult to change our way to speak : flow, diction).

I prefer the larger emissive area for heat and larger emissive area for light of the sample over the V2. Maybe an optional shorter globe (with more angle) could be made to satisfy more people (camper with van vs camper with backpack only).

One detail I appreciate about Astrolux flashlights is the 2 size tripod mounts. The bigger size is for (“Congres”) 3/8-16 UNC thread and there is a removable stainless steel insert, which is more wear resistant, for (“Kodak”) 1/4-20 UNC thread.


Would it be possible at this stage to make this adjustment ?

Great video DBSAR. Thanks again for all the hard work. The lantern looks great.

Thanks for doing the video Den. I enjoyed that discussion of the lantern prototype.

This lantern just looks awsome, only a few little changes and we can start the production. But I would also agree with the others that the bigger top of the factory prototype actually looks better than the V2 prototype, just because the proportions of the lantern are more in balance. On the original prototypes the battery compartment looks far to big compared to the top.
An other thing I noticed is that the buttom seems to be positioned a bit high, maybe it would look better if it would be a bit lower, more in line with the knurling.

Concerning the driver, is there something that will work as an electrical “buffer” to avoid the lantern to turn off with “strong” bumps on the bottom ?
It might not happen with longer protected batteries but might be a problem with shorter batteries that less compress the springs.

It would take “local storage” to do that, which means adding a large capacitor on the driver board. Someone already requested a large capacitor for the purpose of tricking the charger circuit into running without batteries, in order to use the light directly from the charger. But I doubt even a cap just large enough to power through a bump is possible at this point, because the driver hardware is really done and ready for production. Maybe a future version can implement something like this. The real fix anyway is just to make sure the correct combination of springs and battery tube length is used so that bumps aren’t a problem. And to always have at least one cell inside, so the light will work with or without a charger plugged in.

I didn’t/don’t have this problem with my BLF Q8s which need a strong bump to turn it off, I’m not that clumsy when using it :smiley: but I just remember that some people complained about it.

It would either take an additional power source, or some stiff springs.

After reading the TP5100 datasheet it’s a shame it doesn’t look like it offers any configurability regarding the LED indicators.
Most important thing obviously is the charge termination point being correct but as some people prefer an earlier cut-off voltage (since it improves cycle life while capacity loss isn’t that big) it would have been nice if the indicator could be configured to change to green a bit earlier let’s say 90% SoC instead of 100% SoC.

Which would be a win-win, those who want all the capacity can leave it to charge and know they get all the capacity as it terminates correctly at 100% SoC but those who care and prefer improved cycle life could pay closer attention to the charging process and yank it off the charger when the light turns green a tad early.

At least the TP5100 seems to be a bit more sensible with it’s charge cut-off. If I understood the datasheet correctly it terminates at ~ 1/10th charge current. Instead of going on and on closer to the 10-20mA range needlessly stressing the cells while gaining very little capacity.
So with the lantern been set to 1.5A it should be terminating the charge somewhere around the 100-150mA point.

I have noticed that some like the larger head, and its not a critical concern to me so i can have them leave it as that size of everyone agrees.

I’m not sure if the TP5100 chip can be program adjusted, (Toykeeper is better qualified to answer that question) but i do agree, as i prefer a cut off point between 4.15 ~ 4.17 volts, rather than the 4.19 volts. As of right now i feel leaving the LT1 from the factory with the 1.5 volt charging jumper as default, (especially when using high-capacity cells) and possibly having the lantern be shipped with 5 or 6 of the 7135 chips active, and the remaining 2 extras on each channel left open for those who want to increase the output.

Does the V2 and sample lens produce the same amount of output?
Output being equal, I think more compact would be universally better for everyone. I wouldn’t want a larger lantern just because it “seems” right.

Liking where this is going. I’m in for 1

Ok, was thinking of posting a vote poll. (one for the switch LED color, and the other for the lantern lens/head, ( leave it at the current size or shorten it)

Making a poll for that seems to be a good idea. Put before I/we vote for a particular switch color I first want to know what the planned functionality for that switch led is. Is it just a simple location led that helps finding the lantern in the dark, or is it intended to work as a moonlight Led? And does it it have any other funktions like e.g. a low battery warning?

I believe Toykeeper has the firmware sent to allow the brightness adjustment for the switch LEDs, as it can be used as a locator glow, a fire-fly or moon light glow, and unsure but i think a candle flicker was mentioned.

Please put me on the list for one. Thanks!

Poll sounds good.

Come on Den, lets just go with it. A different switch color ok, but no more redesigning please. You’ve done an awesome job, and the lantern looks fantastic. 3 1/2yrs will be long enough.