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

Thanks!

And now, please put me on for a second! :slight_smile:
The more I read about this design, the more I love it …

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Interested based on price. Keep up the good work everyone!

It would be interesting to know how the diffuser wil influence the light in matters of cri and color temp. The one I use makes my lights look cooler.
I know it won’t be possible for this one but, somebody spoke of remote phosphor domes. Wich I believe would be perfect for a lantern. I have looked into them but they seem not available anymore. I know yuyileds (?) uses them cause I broke one of their bulbs. The bulbs are really nice but could be a litter warmer for my taste for some applications.

A diffuser will blend the beam, even if the tint is all over the place from 4000k in the spot all the way to 6500k+ on the edges, which means tint shift goes away. However, that means the beam is blended, meaning that 4000k spot/6500k edge will now become a 5300k tint, which makes the light seems much cooler than it actually is.

Samsung’s LH351D 90CRI 3000l-4000k-5000k have been tested to have very little tint shift, so that should not be a problem at all.

How can we know bout the tintshift if we don’t know what diffuser material wilo be used? I

The LEDs themselves have little tint shift in the beam for the 90CRI versions, so normal silicone diffuser should work without any problems, if it’s made consistently of course.

Thanks for asking that question though!

Does anybody know a source for good high quality diffusers?

Yeah, that’s way beyond what we can do in this project. That’s the sort of thing LED manufacturers experiment with for household light bulbs, not something we can reliably get produced for a lantern.

It’s not even used much by LED manufacturers though. Philips did it for a while with their L-Prize bulb, but it didn’t stick around long. It was expensive, and people didn’t like how it looked.

The main counter-example I’m aware of is a lightsaber blade called a photon blade. It shines a royal blue emitter into a phosphor-coated tube to produce a bright green light. But it’s nowhere near white, and the blade alone (without emitters or a host or driver) costs more than the lantern’s estimated price.

Those are some funky looking light bulbs. I can’t find any of those remote phosphor domes, I did find a store where they where out of stock and they not really budget friendly.

I’d be interested. Hopefully the USB c charging works out :wink:

Very simple, very interesting.

But I’d check if white works OK, so it reflects some light back to the head for increased efficiency. Could be a worse blocker like that, so maybe it’s not a good idea.

Hi everyone, I was away for a couple days, but back now. I sent the driver files & info to Barry from Lexel.

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I got a bit confused about the final decision: did you go for the 7135 version or the FET version?

i believe the FET version was decided on & the design for that model sent from Lexel to me.

Thank you :slight_smile:

Should I take a shot at making code for this driver even though I don’t have the hardware to test on? At least then Barry & Co would have something to flash on the MCU.

I can’t guarantee it would work, but … it might.

I can probably get the tint-control stuff working, at least, since that seems to use pretty standard PWM. But I’m not sure about powerbank functions. I need more info about what the USB and opamp enable pin is supposed to do. Lexel, how should that work? Does the pin enable both the USB powerbank circuit and the primary LED output? I’m not sure if the pin needs to go high for regular LED modes, or for powering other devices, or for charging the lantern itself, or a combination.

I believe Lexel offered to build a test driver, (at an unknown cost, which i am unable to dedicate any large amount of funds to at this time) but i believe Barry was going to have their engineers look at the driver design specs Lexel sent me to see if they can build that FET driver posted earlier. Then it may be possible for them to build some test units to send you. (building the driver is out of my ability range) but you can contact Barry or Lexel directly if you want to get more info on the driver hardware.

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Put me down for one, maybe two.

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im interested in 2 lanterns