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

Please put me down for one more (total 2)

Thank you.

What is the height difference between the V2 and the sample ? Doesn’t seem way more than about 1 cm.

No, I wasn’t planning to have a 4000K turbo mode. It can’t sustain that much heat.

For anyone who missed the details earlier, the lantern has 14 of the 7135 chips, with 7 attached to each set of LEDs. So it can make about 2.45A of warm white and 2.45A of cool white. For the middle tints, it tries to maintain a steady power level while changing the amount of power which goes to each channel. But exactly in the middle, it could also have a 4.9A turbo mode.

In the current prototype, middle tints actually decrease in power because the mixing formula doesn’t account for the non-linear PWM response curve. But I plan to fix that in firmware so it’ll maintain pretty close to a steady power level regardless of tint.

I think the plan is to set the default power limit to 1.4A or 1.75A. This increases the runtime without making it visibly much dimmer, and it also makes the light safer thermally. But those who want more power could simply touch a soldering iron to a couple spots on the battery side of the driver, and it would enable more of the 7135 chips. Creating a solder bridge like this is really quick and easy to do.

That sounds awesome and super easy TK. And thanks for the re-explanation of what’s going on with that. I apparently missed that earlier. :+1:

Maybe this will be the precursor to a BLF light bulb with tint ramping

Looks great, put me down for 1.

I’m only worried about the diffusing material. Looks too white instead of a frosted clear material (Like sticking DC fix to a clear lens). White semi translucid diffusers can degrade over time and turn the tint yellowish/greenish.

I just measured it, and the test unit is 6 Millimeters taller. ( 1/4” inch)

Wow, I didn’t expect that much. Thank you for measurements.

Apologies for being slow, but now I’m really confused - is the plan 14x 7135 chips on the board in total (i.e. 7 per channel) or 7x7135 chips on the board? Also, I’m glad to hear that all 7 chips are going to be populated - I think my soldering skills are up to forming a solder bridge, but probably not up to sticking an extra chip onto a PCB…

Edit: Where are my manners?! Thank you to team LT1 - I am now ridiculously excited about this project. There’s already so much incredible work that you’ve put in, and I’m very grateful for it!

Oops, typo, i meant 6 millimeters. :smiley:

:smiley:

Right after your response I looked again at the pictures trying to figure what I didn’t get. My brain froze with confusion…how could it be 6 cm ?!?

:smiley:

Ah yes, I remember we discussed about it in PMs.

All of the 14 7135s will be soldered in.

However, only 4 per channel will be activated at the same time.

I would love one. Thanks!

That’s awesome that all the 7135s will be populated and that we just have to make solder bridges to bring the others “online”. Very smart and thoughtful of you all. :+1:

That’s what we are planning.

We are planning to limit power via firmware, with only 4x7135 per channel being activated initially.

Edit: See, this is what happens when I’m confused.

I don’t believe that is correct. The plan was to populate all 14 7135s (2 channels, 7 per channel), and allow folks to connect in additional ones by shorting pads. On the prototype all the pads came shorted. Like I think DBSAR said recently only 4 or 5 would be connected as “stock”.

correct, that is the original plan. Have 4 or 5 connected from the factory by default, and the rest left open for those who want to push more output at a sacrifice of run times. I will be testing the maximum run times & amp draw loads with all 7 connected at first, then desoldering a couple of the 7135 bridges on each channel to get amp readings and run time comparisons then. The extra AMC chips are to be on the board for user modifications. (increase in output)

Nope. The control chip doesn’t have the physical ability to activate individual 7135 chips.

There are two ways for the user to adjust the highest power level:

  • Physically connect or disconnect 7135 chips by adding or removing solder bridges on the battery side of the driver. This changes how much power is considered “100%”.
  • Use firmware to adjust the ceiling level lower than 100, if desired. The firmware allows configuring the ceiling level, but it is set to 100 by default. If the user lowers it, 100% will still be available… but it is treated as “turbo” and is only accessible with a double click while already on a lower level.

Today there has also been some discussion of a “turbo plus” which would only work at 4000K color temperature… but I wasn’t planning to add anything like that.

Please place me on the interest list.

I’m already on the list for two, 688 and 689. Please add two more for a total of four.

I plan to pick up 4 full sets: lantern, batteries, case, etc, etc.

The first two are mine. Mine mine mine. The new ones are planned gifts. Depending on overall price, I can see picking up a couple more than four.

Amazing work, thank you.

One side note. I’ve been going out to Burning Man since the late 90s and have rigged up a ton of led solutions over the years. I’m the ‘light dude’ in our camp. This is exactly what I’ve been trying to make as far as a portable lantern goes. I’m not sure I want to be responsible for the possible carnage, but I think a post or three in BM forums would yield a great deal more initial orders. If that’s desired. At a risk of drastically lowering the S/N of this thread.