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

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TheShadowGuy
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The very warm to neutral customizable high CRI tint and promise of the complex software features are what drew me to this light. If I wanted something relatively simple I’d just buy Zanflare T1 lanterns and never bother with a more premium lantern at all. I am buying a Zanflare T1 anyway, but that’s just because I’m a flashaholic and can’t stop myself…

mdeni wrote:
But if i am honest with myself, that “feature” is very silly. I cannot think of a single person that will actually use it, and even less to make a difference for them to buy the light or not.

Quite a few people (myself included) would use that feature and it is a big selling point. Without that “silly” feature and a great UI (what ToyKeeper has mentioned of the UI sounded quite enticing), I don’t think there would be enough to compel me to buy it over other cheaper lanterns or a diffuser.

DBSAR wrote:
As of right now were hoping to go with efficient Samsung LH351D in both 3000Kor 2700K) and either 4000K or 5000K for the cooler side

The bigger the spread the better, in my opinion. The Samsung LH351Ds from what I’ve seen are an excellent choice.

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The_Driver wrote:
The_Driver wrote:
Why not a MOSFET based linear driver with higher efficiency in the low modes like the LD4 and texas commander drivers?

Nobody thinks this is a good idea? Less components and higher efficiency.


Someone has to design it. Designing parts of this lantern has been slow sofar, only now even the driver takes final form and I believe it is nice that it is being done at all and that it will have nice options and firmware. And an even more efficient driver without PWM like you suggest (I agree that for a relatively low-powered light like the lantern a FET-based lineair driver would be a suitable application) would require lots of extra expertise and time. Apart from that, I wonder if you could get output and tint ramping done without old-school PWM?
DBSAR
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TheShadowGuy wrote:

The bigger the spread the better, in my opinion. The Samsung LH351Ds from what I’ve seen are an excellent choice.

I will suggest to the manufacturer to try to source the 351Ds in 2700K for the warm side and 5000K for the cool side of the two channels for tint ramping, that will give a good range of tints.

That Canadian flashlight guy & Lantern Guru -Den / DBSARlight

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DBSAR wrote:
TheShadowGuy wrote:

The bigger the spread the better, in my opinion. The Samsung LH351Ds from what I’ve seen are an excellent choice.

I will suggest to the manufacturer to try to source the 351Ds in 2700K for the warm side and 5000K for the cool side of the two channels for tint ramping, that will give a good range of tints.


I think it is too much to ask for Sofirn, but if you never ask for it you will certainly not get it:
Could you ask for the 2700K led for one of the colour-bins W1 to W8, and for the 5000K leds for colour-bins R1 or R2? These Samsung tint bins are on or below the black body line, if Sofirn was able to source them (in 90 CRI of course) that would be awesome for the tint of the Lantern.
DBSAR
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djozz wrote:
I think it is too much to ask for Sofirn, but if you never ask for it you will certainly not get it: Could you ask for the 2700K led for one of the colour-bins W1 to W8, and for the 5000K leds for colour-bins R1 or R2? These Samsung tint bins are on or below the black body line, if Sofirn was able to source them (in 90 CRI of course) that would be awesome for the tint of the Lantern.

Will definitely talk to Barry and pass that info on to him.

That Canadian flashlight guy & Lantern Guru -Den / DBSARlight

sbslider
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djozz wrote:
And an even more efficient driver without PWM like you suggest (I agree that for a relatively low-powered light like the lantern a FET-based lineair driver would be a suitable application) would require lots of extra expertise and time. Apart from that, I wonder if you could get output and tint ramping done without old-school PWM?

I am in search of a bit of education in regards to efficiency and driving LEDs. In the area where I am familiar, power supply design, PWM kicks the doors off efficiency vs linear every day of the week. What is it about the LEDs that this is not so? Is it that the voltage drop across the linear regulator is small, due to the close LED Vf and the prime voltage source (rechargable lithium battery)? Or PWM plus the linear current regulators is double loss? I would be interested to read more about this if someone can point to some reference material.

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fixed it
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sbslider wrote:
I am in search of a bit of education in regards to efficiency and driving LEDs. In the area where I am familiar, power supply design, PWM kicks the doors off efficiency vs linear every day of the week. What is it about the LEDs that this is not so? Is it that the voltage drop across the linear regulator is small, due to the close LED Vf and the prime voltage source (rechargable lithium battery)? Or PWM plus the linear current regulators is double loss? I would be interested to read more about this if someone can point to some reference material.

It’s the LED itself. Lower current = more lumens/W. Some of it is due to less heat (which I think does not change significantly with or without PWM) but I believe some of it is intrinsic to the conversion of electricity to light. And that part means more efficiency by running at say 1 mA than at 100 mA with 1% duty cycle.

And the PWM we talk about here is not the PWM of power supplies. It’s a duty cycle for a linear regulator… nothing efficient about it. Some drivers do have more efficient design of course, much like modern power supplies.

One last thing: I don’t know about the LEDs being discussed here but some change tint and probably CRI too depending on current. So a linear driver might not be desirable at all because of that.

And I learned most of that around here. Couldn’t dig up the exact threads but djozz’s LED test threads are usually a good place to start to read technical discussions. So are the driver design threads. Unfortunately some of it may be lost in other places. Stick around and the information will eventually percolate lol

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@DBSAR, I have already spoken to Sofirn about the bin tints and LED tints to use with the right order code. That was a WHILE back though, so they may not remember about it.

However, if Barry can confirm which LEDs they’re using, they should be these, if I’m not wrong:

-5000k LH351D 90CRI (Part number: SPHWHTL3DA0GF4RTS6)

-3000k LH351D 90CRI (Part number: SPHWHTL3DA0GF4VPP6)

@sbslider, this is in regards to the type of linear regulator used. It can either be a single purpose linear regulator, like a 7135, or a FET used as a linear regulator

FET as a linear regulator, will always be better, but let me explain.

- A single purpose linear regulator will run at a constant current set by its specs at 350mA. – If ran at 100% duty cycle, the linear regulator will output 350mA to the LED. – If ran at 50% duty cycle, the linear regulator will output AN AVERAGE OF 175mA, meaning the LED will still see 350mA, but at half the time. This is what we usually do in linear drivers. However, they don’t behave well at thousands of hz, and the efficiency of the LED stays constant, even though the average current will be lower. While in fact, it should be more efficient.

This is where the FET as a linear regulator is very useful, rated at say 350mA.

– If ran at 50% duty cycle, it will output a constant 175mA, meaning the LED will now see 175mA, and its efficiency will be increased at lower current, along with the FET easily handling 100s of kHz of frequency, removing parasitic inefficiencies.

My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547

Eraursls1984
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djozz wrote:
DBSAR wrote:
TheShadowGuy wrote:

The bigger the spread the better, in my opinion. The Samsung LH351Ds from what I’ve seen are an excellent choice.

I will suggest to the manufacturer to try to source the 351Ds in 2700K for the warm side and 5000K for the cool side of the two channels for tint ramping, that will give a good range of tints.


I think it is too much to ask for Sofirn, but if you never ask for it you will certainly not get it:
Could you ask for the 2700K led for one of the colour-bins W1 to W8, and for the 5000K leds for colour-bins R1 or R2? These Samsung tint bins are on or below the black body line, if Sofirn was able to source them (in 90 CRI of course) that would be awesome for the tint of the Lantern.

The major downside to the 2700K is the significant drop in efficiency compared to the 3000K. I’d prefer 2700K of they were the same or close, but would prefer efficiency since they are not.
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@ BlueSwordM and fixed it, thanks for the explanations. I definitely have noticed that LEDs get way less lumens/mA (or lumens/W) when they are driven very hard. But I was under the belief (perhaps, or likely wrong) that at lower drive currents, the lumens/mA curve was pretty constant. So with 4 LEDs each drawing 350mA (fairly low current) the efficiency of the 4 7135s can be no worse than the efficiency of a single FET. But at lower currents, if the switching performance of the 7135 is lousy (sounds like a great BLF improvement project!!) then I can see where the efficiency of the single FET would be better.

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Agro
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The_Driver wrote:
The_Driver wrote:
Why not a MOSFET based linear driver with higher efficiency in the low modes like the LD4 and texas commander drivers?

Nobody thinks this is a good idea? Less components and higher efficiency.


Me thinks so
Agro
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djozz wrote:
The_Driver wrote:
The_Driver wrote:
Why not a MOSFET based linear driver with higher efficiency in the low modes like the LD4 and texas commander drivers?

Nobody thinks this is a good idea? Less components and higher efficiency.


Someone has to design it. Designing parts of this lantern has been slow sofar, only now even the driver takes final form and I believe it is nice that it is being done at all and that it will have nice options and firmware. And an even more efficient driver without PWM like you suggest (I agree that for a relatively low-powered light like the lantern a FET-based lineair driver would be a suitable application) would require lots of extra expertise and time. Apart from that, I wonder if you could get output and tint ramping done without old-school PWM?

Isn’t Texas Commander the right driver?
Kingjohn
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please put me on the list for one…

The_Driver
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Agro wrote:
djozz wrote:
The_Driver wrote:
The_Driver wrote:
Why not a MOSFET based linear driver with higher efficiency in the low modes like the LD4 and texas commander drivers?

Nobody thinks this is a good idea? Less components and higher efficiency.


Someone has to design it. Designing parts of this lantern has been slow sofar, only now even the driver takes final form and I believe it is nice that it is being done at all and that it will have nice options and firmware. And an even more efficient driver without PWM like you suggest (I agree that for a relatively low-powered light like the lantern a FET-based lineair driver would be a suitable application) would require lots of extra expertise and time. Apart from that, I wonder if you could get output and tint ramping done without old-school PWM?

Isn’t Texas Commander the right driver?

We need a dual channel version of that.
deleted-200707
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unsubscribed

I have less interest in Lumintop than they have in their customers

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Huh? Lumintop isn’t building the lights, it’s Sofirn actually.

My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547

deleted-200707
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Then I’m happy and disregard my Lumintop warning. Smile

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chinooker wrote:
unsubscribed

I have less interest in Lumintop than they have in their customers

I don’t know what Lumintop did to offend you, but it would be great if you could stop spamming every single thread. If you have something to say, make your own thread and say it.

Find all my reviews of flashlights and more gear at www.bmengineer.com

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Kingjohn wrote:
please put me on the list for one…

Kingjohn added to the interest list at number 957

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Lexel
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first request was just 2×4AMC driver

added Powerbank stuff

CC regulated MOSFETS

7135s removed
CC regulated without PWM added
LDOmadded
indicator Led removed for voltage divider

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Lexel wrote:
CC regulated MOSFETS

7135s removed
CC regulated without PWM added
LDOmadded
indicator Led removed for voltage divider

Wow. I’m up for that one!

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Looks like the surgery didn’t slow you down? Very impressive. Thanks for your all your efforts!

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Nice! Thanks Lexel!

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WOW Thumbs Up Beer

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severide
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Nice job, Lexel! Thanks!

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If I could buy these guys a beer I would buy them a bar. Thank you all for making this come true!

Armytek Prime C1 Pro, Armytek Prime C2 Pro, Armytek Tiara C1 Pro, Astrolux MF01 Mini, BLF Q8, BLF A6, BLF FW1A, BLF FW3A, BLF FW3C, BLF LT1, Convoy L6, Convoy C8+ , Convoy S3, Convoy M21A, Convoy S11, Emisar D4, Fireflies E07, Jaxman E2L, Lumintop EDC18, Manta Ray C8.2 long version, Olight S1R Baton II special edition series, S2R Baton II, Nitecore HC65, Olight H1R Nova.

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The_Driver
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Lexel, what is the lowest possible current with that FET driver?

Lexel
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its one Channel PWM and should not suffer from low PWM cycle like AMCs are so 0.4%

I am not sure which current we get with lowered MCU voltage
from 5V as DELs driver was designed, here we got 2.8V we should get about 60%

Not sure which current he calculated, need to be tested

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Sign me up.

Do we have any price estimations?

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mdeni wrote:
Sign me up.

Do we have any price estimations?


mdeni added to interest list at 958, too lazy to add the next poster at 959 . . . Wink

As far as price goes, nothing firm, IIRC maybe $30-$40, depending on the final feature set.

PocketSammich wrote: I don’t need this, but I want it. Please sign me up.

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