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

angerdan · 2017-09-15T13:49:22.000Z

Zulumoose:

ideas for other features:

waterproof slot for matches, usb cables etc

12v input

Timer to off or moonlight mode

threaded base for tripod mount

flap or curtain for creating a shadow side, ideally reflective for more output to the other side

My thougts for this are:  
1. would make the lantern bigger, but maybe there’s a nice compromise (also weatherproof will be more realistic and less expensive than waterproof)  
2. if USB input supports QC 2.0, 12V would be possible with standard gear (regular USB Type-C or 3.0 cable and USB QC powerbank or power supply)  
3. nice idea, also for childs  
4. like with the Fenix CL20R, magnetic tripod mount would be perfect :)  
5. this should be optional, to make it cheaper for people don’t needing it. Clever would be an electronic solution with controlling half of the horizontal LEDs separately (like the Cateye Rapid X3)

DBSAR · 2017-09-15T16:23:40.000Z

ok Miller sent me some info on the Q8 design. I will work on a basic specification description of a combination of my current prototype above using the Q8 battery tube/base possibly, (with drawings) and explanation on how the lantern could be used with the extra mentioned ideas mentioned. The Q8 driver may be a bit to much for a lantern, ( the higher modes would cause severe overheating very quickly and short run times on the higher modes) as for lanterns continuous run times are among the most important. Right now the prototype pulls roughly 700-mA on high, (from a modified 2-7135 Q-Lite driver) and keeps the XP-L U5-5A3 emitter right in its most efficient maximum lumens-vs-amp-draw range, and will give a full weekends worth of use on high with a single charge from four 2500mAh 18650 cells, but giving the light output of an incandescent 40-watt light bulb.

sac02 · 2017-09-15T17:22:44.000Z

Per the Cree datasheets, 700ma through a U5 XP-L is about 265Lm.

In real world use that is plenty of light to sufficiently illuminate a small outdoor campsite or large room indoors. And I do think 250 or less will be the most commonly used level of the lantern. But I also think that it would be nice to have higher outputs (I mean, this is BLF after all) of maybe 500Lm available somehow.

What kind of driver did you have in mind for the production light, did you want it to be 7135-based?

If it is 7135 based, the PCB could easily be designed to accept additional 7135’s so that even if the production light shipped with 2*7135, the mod-minded users could add one or two more.

The_Miller · 2017-09-15T19:26:01.000Z

There you go…
A smaller MCU, less parts GLR driving the led, leaving lots of space for the cool charging and powerbank functions on the driver board.

Tally-ho · 2017-09-15T19:41:52.000Z

Wouldn’t it be possible to have the charging and powerbank fonction within an add-on part screwed between the head and the battery carrier that can be unscrewed when you don’t need it or when the weather turn bad…except it both ports are well protect like the muni-USB of the zenflare F1.

DBSAR · 2017-09-15T20:34:31.000Z

sac02:

Per the Cree datasheets, 700ma through a U5 XP-L is about 265Lm.

In real world use that is plenty of light to sufficiently illuminate a small outdoor campsite or large room indoors. And I do think 250 or less will be the most commonly used level of the lantern. But I also think that it would be nice to have higher outputs (I mean, this is BLF after all) of maybe 500Lm available somehow.

What kind of driver did you have in mind for the production light, did you want it to be 7135-based?

If it is 7135 based, the PCB could easily be designed to accept additional 7135’s so that even if the production light shipped with 2*7135, the mod-minded users could add one or two more.

When i first built the prototype it had three 7135s, ( for 1.05 amps) and was roughly 500 lumens on high. a high-mode with 1 amp draw on four 3200mah 18650s will still give a good usable run time of 14+ hours then i tested.

The_Miller · 2017-09-15T21:16:35.000Z

Samsung 35E seems more attractive each day it seems, for the GT and for the lantern.

sac02 · 2017-09-15T21:42:34.000Z

I was just looking at the 35E the other day on US battery distributor websites (Liionwholesale, IMRbatteries) and they aren’t available on one, and are $6.50/ea +shipping on the other. Has anyone seen them yet on the usual Chinese sites yet? I agree they would be ideal for this lantern or the GT.

(But I have a bunch of Sanyo GA’s ready and waiting for the GT)

I will give one additional - though not particularly compelling - reason why I like the potential of adding a USB-out (powerbank) function. The last time I went out camping I took some LED strip lighting that I had cut and wired up to the right length to illuminate the EZ-up canopy and it worked really well. I used 12V strips, and ran it off a 3S 18650 holder. Those little 2835 SMD LEDs are surprisingly effective, in case you haven’t played with them. If you instead purchased 5V strips, you could run LED strip lights directly off of your BLF lantern. It might not be ideal, because if you want to grab the lantern and go pee, you’d have to unplug the strip lights, but it would be a neat party trick to use the lantern as a power source for the larger camp lighting.

Obviously the much more common use for a 5V USB that most would appreciate would be to charge other electronics like phones.

The_Miller · 2017-09-15T21:48:14.000Z

How many people would try to charge a notebook when 12V out was present ?

12v in seems clever, east to add a car charger to package.
12v out, hmm
I am using 10m and 20m light strings all around (on bridges, ar the fence) that charge a single AA cell with the sun and light up all night. Lots of those stings are sold with 3*AA cases too andni have two with USB that I use with a powerbank during Christmas time. Indeed very cool to use while camping to show where those tent ropes are at night for example.

JorisFRST · 2017-09-15T21:56:52.000Z

The Miller:

How many people would try to charge a notebook when 12V out was present ?

Laptop will pull quite a bit of of power, think most will easily do 60 watts and probably need 19-20V anyway, so it’s not going to last long or be very efficient.

Texas_Ace · 2017-09-15T22:28:32.000Z

The Miller:

There you go…
A smaller MCU, less parts GLR driving the led, leaving lots of space for the cool charging and powerbank functions on the driver board.

The FET takes up the same amount of room as two 7135’s plus the 7135’s have to have a good thermal path to the head in order to not throttle. The MCU also would not change unless firmware was created for the next gen MCU’s. In which case they could be used on any driver the same way.

Still a buck driver would net you higher efficiency and longer runtimes.

Space is not the issue with the driver anyways, the issue for this light is efficiency. A linear driver is very inefficient and will drastically reduce runtime.

If a linear driver / pwm driver were to be used, then it doesn’t really matter how you do it, it will be about the same. More then 2 7135 chips and the Q8 setup will take up less space though.

On top of that, using the Q8 head as it with a screw on bezel attatchment would net a few positives.

First the 4 LED’s would net higher efficiency and longer runtime

Then people could use the Q8 as a Q8 or a lantern by simple swapping the bezel, meaning there are already 1500 lights on order that could use it

anycolourfloyd · 2017-09-15T22:35:17.000Z

Interested, estimates as to how far off production?

DBSAR · 2017-09-16T00:51:03.000Z

UPDATE - I fixed all the Original-Post images of the lantern, (where photobucket had cut us all off from embedding images i now switched over to Imagur.) - For those new to the BLF Lantern project the images are now working for you to see the OP. *

alternety · 2017-09-16T19:30:05.000Z

Newly following this thread after a long hiatus, I am not really understanding the merits of some of the design parameters.

An added note: I saw the picture with the flashlight underneath, and forgot about the fact (which I know from long ago) that the actual LEDs were on the top. Not using the LEDs in the flashlight. This invalidates what I said concerning the Q8 as a direct light source.

Texas_Ace supports the idea of removing the Q8 bezel and screwing in the lantern part. I really don’t think that is the optimal approach. It requires the user to carry around the Q8 bezel and the lantern if they may want to use the Q8 to do more than just being a lantern. And they have to exchange the functional units in the dark (and rain, snow, dust [think garbage in the threads], etc.). A Q8 would have significant other applications as a standalone flashlight. I believe the most versatile approach would be a clamp on the lamp portion to fit the Q8. This would make it easier to interface with other flashlight bases with different threads, sizes, and configurations.Why make the lantern diffuser dependent on a specific light source? Making this clamp adjustable (preferable), or offering selected alternate clamps, would greatly expand the possible purchasing population.

An adjustable stand for supporting the lantern would be necessary. For a camp light one can not really assume a nice even surface is available. So a set of tripod legs with an adjustable clamp will fill the bill.

So you have a lamp that takes multiple versions of flashlights and stands up well on an irregular surface. And all of the flashlights used can be simply removed for use as a flashlight. You now have a system that does not require a specific flashlight as its’ base.

Power is another issue. First of all, if you are configuring for multiple light sources, the direction of the development on power functions is not viable.

If things do not move to my suggested configuration, there are issues. If the light is used to charge phones and other things, they will be better served by the popular battery recharge packs with Li batteries in them.

If you want to use a battery charger pack to recharge an independent custom light source; this is not an optimal energy path to recharge a lamp. The battery pack is a set of cells (probably moderate capacity) and a voltage converter. There are power losses there. If you are going to haul around a recharging pack, use it for phones. If you want to charge the lamp from a battery pack; the energy issues are worse.

It is simple, and more efficient, to just carry some spare Li cells. If you want to charge phones, carry a pack to do this. In the majority of real world cases, the light will be the primary requirement; not the phone.

There are relatively inexpensive cell chargers for inputs of 120 VAC and 12 VDC. When the lantern light goes out, it is unlikely the user will say that it is OK, because by tomorrow afternoon the light will work just fine. Or an hour; or 5 minutes. Replacing discharged cells is quick and easy. Discharged cells can them be connected to a 12 VDC charger and fairly quickly be replenished by a transport device (car). Remote operations with a solar charger can be a similar situation. Leave the solar panel charging cells in camp, and you have fresh batteries when you get back. A set of charged cells in holders is lighter and quicker than other portable recharge approaches.

I really want the lantern light dispersing parts to work on the Q8. Other lights with my suggestions are a bonus which should improve the volume for manufacturing.

DBSAR · 2017-09-16T05:19:58.000Z

Another photo of the well-tested & beaten prototype with my favorite Rum back on my east coast trip, here in the wilderness with the moon in the sky. ( lantern was on Low mode for this photo)

DBSAR · 2017-09-16T05:25:56.000Z

The Miller:

Samsung 35E seems more attractive each day it seems, for the GT and for the lantern.

The 35E x 4 (with 3500mAh) in the Lantern would give amazing run-times even on a 1-amp high mode. (that’s 14 Amp-hours of total capacity!) a single charge of 4 cells would give a long weekends of use easily.

cabfrank · 2017-09-16T05:52:06.000Z

That’s a really great picture, and I bet the rum is tasty too.

swissbianco · 2017-09-16T07:46:43.000Z

im interested in that lantern too.

ToyKeeper · 2017-09-16T08:05:29.000Z

If it’s a Nx7135 or FET+1 or FET+N+1 linear driver, the driver should be a fairly quick and easy matter since there are already several good designs available. If it needs to be a boost/buck driver, or if it needs USB charging / powerbank functions, you’ll definitely need one of BLF’s overworked and underappreciated circuit designers to help create something new.

There should at least be plenty of room for boost/buck components, especially if it only needs 500 lm.

As long as the driver isn’t too crazy though, I should be able to put together some firmware for it reasonably quickly.

Of course, the easiest lantern solution would be a bezel attachment for the Q8. If that isn’t appealing though, it sounds like there are a variety of other options if people are willing to put in the work.

Agro · 2017-09-16T10:20:53.000Z

The Miller:

How many people would try to charge a notebook when 12V out was present ?

12v in seems clever, east to add a car charger to package.
12v out, hmm
I am using 10m and 20m light strings all around (on bridges, ar the fence) that charge a single AA cell with the sun and light up all night. Lots of those stings are sold with 3*AA cases too andni have two with USB that I use with a powerbank during Christmas time. Indeed very cool to use while camping to show where those tent ropes are at night for example.

That’s a VERY interesting concept. Frankly, I haven’t considered a SRK lantern other than a diffuser for Q8.
But add a powerbank with enough power to run a laptop and with replaceable batteries (so I can run it for long) and it’s indeed an interesting concept.