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

You’re doing some very impressive design work here, DBSAR :beer:

Looking at the star with 2 LEDs on it, I just had a random thought: would it be worth having two 3000K LEDs and two 5000K ones?

I have a picture in my head of two Convoy S2+ tailcaps set into the top of the lantern, allowing the user to physically switch the two colour temperatures in and out separately. You could have 3000K for relaxing in the evening, 5000K for a work light, or an extra efficient “4000K” mix getting a few more lumens per watt by spreading the power over 4 LEDs.

I have no idea whether any of this is possible or sensible, mind :slight_smile:

DBSAR…what if you added a white wall around the LED meant to make it invisible from the sides?

Interested!

Add me to the list :).

If you use just two batteries in the battery tube, together with two XP-L’s it should be good to go for testing: too much output on max but he leds should be good.

Or else, you could use a simple resistor in the circuit to tame the driver, try 0.1 Ohm for a start. If you use an old-school 0.1 Ohm 1W capable through-hole resistor you could even use it floating, soldered in the middle of one of the led wires. That will eat up a few 10th’s of a V, drastically reducing the current. It is how many drivers of this type are tamed in stock flashlights.

Electronics experts please correct me if I’m wrong.

I thought the Q8 driver was a FET +1 design. If so, the thing to do is get a two channel driver that uses 7135’s for both channels (or a three channel driver). Have it configured with one bank of just a few 7135’s and the single 7135 “bank” and leave the rest of the spaces unpopulated. Get Narsil installed on it, and you have functionally the same mode sets and UI as the Q8 but with a lower max regulated output. This will allow you to test run-times more accurately than if you just try to hobble the FET on the Q8 driver to make it put out less current. I think Texas_Ace or Lexel could help you out with that driver, if you tell them what you’re trying to accomplish.

FET+1 is not really a problem when adding an inline resistor, if the driver is using the 7135 just some heat-burn-off will be transferred from 7135 to the added resistor, and the ramping curve will be very slightly affected but I doubt that you will notice it.

The V1-Prototype had that design, ( if you go to the OP and have a close look at the photos of it you can see the white band around the top of the lens) but with a higher percentage of frosting for the lens it would not be that noticible.

Interesting idea indeed. Not sure how much it would add to the cost of the lantern overall to add a switch to the top and have two different tint sets of LEDs.

I thought of that resistor method which is what i done to reduce current in most of my driverless lantern mods. But with this thing putting so much amps out i[m unsure of the heat issue with a resistor getting to hot, or of which one to use.

Ok, I just thought ‘regulated’ would be inherently more efficient than a hobbled FET, which is ‘not regulated’ AFAIK. But then, I don’t know much, so the likelihood of my being wrong is great! :stuck_out_tongue:

I’m not sure how physically feasible it is to put a stack of 7135 chips on the FET pad. With the 7135’s middle/wide pin up, IIRC, that means from left to right the pins are LED~~, GND, PWM. Meanwhile, the FET has four pins and a big pad. The three leftmost pins are GND, the right pin is PWM, and the big pad is LED~~.

Adding a Moonlight Special driver as a slave board might be an option, for testing. Or a slave board with only 7135 chips on it, wired to/from the Q8’s FET pad. Or using a FET+N+1 Q8 driver without the FET. Texas_Ace made a nice 46mm one:

https://oshpark.com/shared_projects/tEWsX9HP

Or Lexel sells some pre-made:

He might even be willing to put Anduril on it. The ramping table will be a bit messed up with the second power channel so low… so it’d probably be a good idea for me to make a special build for it.

A floating inline resistor is how lightsaber drivers work. They’re basically direct drive with a resistor on the low-Vf channels. On those designs, the resistor has a tendency to turn into smoke… but the Vf of a red XQ-E is a lot lower than XP-L.

It’s definitely an easy solution for testing purposes, though the output won’t be regulated at all.

About a 3000K+5000K mix, that’d probably be do-able but would require some redesigning. The driver is going to have two channels regardless, whether that’s for low and high power or warm and cool CCT. But in the latter case it’ll need two equal sets of 7135 chips, a new MCPCB, and the firmware will need some significant changes.

If a second button is used, it would need even more changes, including the host design, and I’ll definitely need some 2-switch hardware to use for firmware development. It could maybe be something like one switch for regular controls, one switch strictly to control color temperature. I have a mechanism in FSM which allows input events to “fall through” top layers where they’ll be handled by lower layers, which would make it pretty easy to make the two buttons completely independent of each other regardless of which mode the light is in. The second button would just fall through to something which handles tint changes.

Color change functionality could still be done on only one button though. It’s mostly just a matter of how to map it into the UI, and what (if anything) to remove to make room. Like, maybe in regular output mode, “click, click, hold”, which is currently unused, could be used to ramp back and forth between tints. And then it’d apply globally to all modes. Or that could fall through as described earlier, so there’d be a single action for tint changes which applies to all* modes.

* “Click, click, hold” is already used during the “off” state and “lockout” state, so those mappings would collide. Also, all mappings are used in “momentary” mode, so tint adjustments would not work there either. It would otherwise be global though.

Oh, um, also, going from two LEDs to four will probably increase the price a bit. But since XP-L isn’t really necessary, that helps. XP-G2/3 or Nichia 219c costs less than XP-L.

I think Phlogiston meant 2 hard switches so you use just one control channel and connect and disconnect the different leds to it

The colour temp change does necessarily have to be done in the software, it could be a physical switch in the ledwire.

https://nl.aliexpress.com/item/OMTEN-PBS1203B-12mm-L-12mm-W-x-9-2mm-H-LED-Flashlight-Clicky-Switch-Black-5/32691557982.html

Hate to add to the peanut gallery again, but I don’t personally see the value of having two separate LED color temps. If I want warmer or cooler LEDs than what the lantern comes with, I’d rather swap them myself instead of having two that stay off all the time. This just sounds like what cheap headlights and some Nitecores do with a primary cool white emitter and secondary warm white ‘reading light’.

Personally, I can’t see why I would switch back and forth - but that’s just me. On the other hand, for those people that need a red light, it would be easy to mod the color temp they don’t like with red emitters as well. Either way, I really like the way this is coming along. Can’t wait to see production prototypes and hear more about release dates and prices!!

Adding more physical buttons, even if they’re simple toggle switches along the LED wires, makes the host more complicated. I can’t rule it out as a possibility, but one button is easier to do than two or three. It already has spots taken by the e-switch and USB port(s).

I have found color changing to be a useful feature on light bulbs sometimes, and I frequently mix tints in light fixtures to produce a better result than any single tint alone, so I can see the appeal of being able to blend. But I have no idea if that’ll happen on this lantern.

In any case, it’s possible, and there are at least four different ways to do it… but it has not been a consideration before today.

Thank you for the expertise & help on this! - I have removed the FET from the Q8, and piggy-backed on a 105C driver board, (stripped of all its components except for three AMC7135 regulators, and remote wired them in to the Q8 driver, so now after testing the maximum amp draw is 1.05 amps on maximum mode. The V2 lantern prototype is now alive & running. :slight_smile:

photo below showing the piggy-backed 105C board with three 7135s in place of the FET.

Driver wired back into the light, ( i encased the 105C 7135 carrier in a shrink tube casing for insulation)

UPDATES, May,8,2018

- The V2 BLF Lantern prototype is now up & running! First tests are underway, (with measurements, comparisons to the V1 and other lanterns, etc.)

- I have yet to still install the TP4056 charger board & plug port, and wire than into the Q8 driver so it can be charged up via Solar panels, wall plug, or vehicle port like the V1 has. I may also change the green switch boot LEDs to a amber or orange LEDs, so that can serve better as a nightlight/firefly option when the lantern is off. SO far, the V2 seems to be slightly brighter on high mode (using the 5-mode group of the Q8 driver, & on high its drawing 1.05 amps from the four 18650 cells, which will give this lantern a run time average of 15 + hours , at around 600 ~ 650 lumens on high mode, using four 3500 mah cells from previous testing at that amp range in the V1 lantern & other modded lanterns i have.
Right now, the V2 has two 3000K XP-L 7A emitters, which gives it a more incandescent light similar to a regular filament light bulb, close to that of a 50 watt incan on high. ( the V1 currently has a single 4000K XP-L emitter.

( photos coming soon showing the smoother & more even light emittance of the V2 over the V1 with the new frosted main single globe/lens & dual emitters.)

- A new basic blueprint & design drawing is under way as well, which will need to be created as a finalized CAD for Thorfire to have the base to work from towards a production version. As for the final driver design & workings to add the charger option, that will require the help of those knowledgeable in that field, as ToyKeeper has worked on adding the Candle-mode and sunset mode for the lantern.

Below Showing the BLF Lantern V2 (on the left in the photo) giving first light, (on the Low mode) along side the V1 lantern on low mode.

Below you can see the warmer tint 3000K of the two XP-L emitters of the V2 on the left, , versus the 4000K single XP-L in the V1 on the right.

Below you can see the new V2 prototype is slightly shorter & more compact than the V1 version. (also the V2 has a new lanyard design where the paracord stays outside the lantern head, making it more sealed.
The actual Lantern blueprint will have some of the body fins removed to slim it down and lighten its weight, ( as all the fins are no longer needed to cool that mid-section area like it does in the Q8 flashlight does, also the head will have some fins added to help with cooling the LEDs.