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

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.

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.

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

Interested, estimates as to how far off production?

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. *

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.

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)

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.

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

im interested in that lantern too.

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.

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.

Run a laptop? That’s silly. If you want good efficiency, get a tablet. Those can run 10 to 15 hours on the built in battery.

Yes I wanted to convey that 12v out seems not smart to offer

  1. I find laptops WAY convenient than tablets.
  2. I find a power bank WAY cheaper than tablet. Especially that I have batteries anyway.
  3. 4*35E holds more energy than an average laptop, though there’s conversion loss.
  4. If I use all my high-capacity batteries, I could run an energy-efficient laptop for entire weekend. Or my i7-7700k one for 12 hours. :slight_smile:

You doing business work out in the woods? Lol

If I go camping I want to be left alone, and the quality of the latern and runtime is for me the top priority, the other stuff is nice to have, but if it would impact the quality of the lantern I’d rather do without the other stuff.

Agreed. You are camping, leave the laptop at home and use your phone if you MUST check email (or Facebook if that’s your thing). Or as Jason said, a tablet if you can’t survive for a weekend with “just” a phone screen (but them why are you camping at all?) and as was mentioned, most laptops need 19v anyway, so the point is moot IMO.

Now on the other hand, 12v in seems highly useful, being able to charge the light from a car or 12v solar source adds a lot of functionality.

I think if it is decided to go with 12v out, it should be in the form of a cigarette lighter socket. That means any car adapted devices including usb adaptors, lead lamps, car vacuum cleaners, mini compressors or airbed inflators can be used. Sounds useful but it seems like a bit of a stretch at the same time, a big ask for 4x 18650s, and the potential amp draws make the required components probably a bit chunky and expensive.

Maybe a task for another project, a one-size-fits-all emergency power source, with adaptors for everything and a light for convenience.

no way i can imagine a boost circuit to make the 2.9-4.2V cells deliver 12V would make sense and probably is very expensive
Lets forget about anything other then 5V USB out please.