Even though we are using a more complicated driver circuit and 8 LEDs, Samsung LH351Ds are much cheaper when bought in bulk than Cree LEDs, so that should balance out.
It also needs less thermal mass since it will absolutely never exceed 1000 lumens except if modded, so less metal is needed.
@stereodude, it is actually going to be using a linear FET instead of 7135s.
This allows for no PWM, perfect constant current allowing for greater efficiency of the efficiency, and no parasitic inefficiencies coming from PWMing 7135s.
Fitting it under 40€ or 39,99€ with shipping, means no import taxes in many countries. That means the light is 39,99 to the door. A 41€ light with tax is more than 55€ to the door.
Even though we are using a more complicated driver circuit and 8 LEDs, Samsung LH351Ds are much cheaper when bought in bulk than Cree LEDs, so that should balance out.
It also needs less thermal mass since it will absolutely never exceed 1000 lumens except if modded, so less metal is needed.
I do think it’s going to be 40$.
They should charge a few extra bugs.
I don’t want an manufacturer to make loss, like Lumintop on the first round of the GT.
Thanks Lexel for designing the driver. It looks good. I hope your hand is doing well. Now about that question from The_Driver.
The_Driver wrote:
Lexel, what is the lowest possible current with that FET driver?
Lexel wrote:
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
Lexel, you know better than me for sure, because I know zero. But I do know that the led4power drivers have a separate channel for moon mode that uses only a resistor and doesn’t use the FET at all, to get a low enough output. Unless you’ve done something led4power couldn’t/didn’t do to get lower output from the FET, it might not be low enough for some people. For me, there probably isn’t any need for an actual moon or firefly level mode. This is a lantern, with light shining in all directions, not a flashlight with the beam concentrated in one direction.
—
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
For me, there probably isn’t any need for an actual moon or firefly level mode. This is a lantern, with light shining in all directions, not a flashlight with the beam concentrated in one direction.
The lighted switch on a Q8 (and probably this lantern) is bright enough for some purposes. Brighter than firefly, lower than moonlight.
What moonlight in a flashlight means to me is enough to find your way around a room or search for something with night adapted eyes, without the spill disturbing sleepers.
In a lantern this is not a practical aim, as if bright enough to light the room for searching, it is maybe too bright to wave around without disturbing sleepers. In a lantern I think the lowest setting (in warm tints) should enable a sleeper to wake up and immediately grab keys/glasses/flashlight/phone etc left lying around the lantern, but not much brighter than that. I have no idea what this translates to in lumens for a 360 degree beam, but would be interested to find out.
Harder to test I would imagine as well, since the lantern won’t fit many DIY lumens test rigs, and would need a sphere, right?
For me, there probably isn’t any need for an actual moon or firefly level mode. This is a lantern, with light shining in all directions, not a flashlight with the beam concentrated in one direction.
The lighted switch on a Q8 (and probably this lantern) is bright enough for some purposes. Brighter than firefly, lower than moonlight.
What moonlight in a flashlight means to me is enough to find your way around a room or search for something with night adapted eyes, without the spill disturbing sleepers.
In a lantern this is not a practical aim, as if bright enough to light the room for searching, it is maybe too bright to wave around without disturbing sleepers. In a lantern I think the lowest setting (in warm tints) should enable a sleeper to wake up and immediately grab keys/glasses/flashlight/phone etc left lying around the lantern, but not much brighter than that. I have no idea what this translates to in lumens for a 360 degree beam, but would be interested to find out.
Harder to test I would imagine as well, since the lantern won’t fit many DIY lumens test rigs, and would need a sphere, right?
Yeah, I think we’ve both got the same idea. I might not have been clear enough though. I think the lowest amount of light that the FET can do will NOT be as low as the classic moonlight levels but WILL certainly be low enough for lantern use.
—
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
For me, there probably isn’t any need for an actual moon or firefly level mode. This is a lantern, with light shining in all directions, not a flashlight with the beam concentrated in one direction.
The lighted switch on a Q8 (and probably this lantern) is bright enough for some purposes. Brighter than firefly, lower than moonlight.
What moonlight in a flashlight means to me is enough to find your way around a room or search for something with night adapted eyes, without the spill disturbing sleepers.
In a lantern this is not a practical aim, as if bright enough to light the room for searching, it is maybe too bright to wave around without disturbing sleepers. In a lantern I think the lowest setting (in warm tints) should enable a sleeper to wake up and immediately grab keys/glasses/flashlight/phone etc left lying around the lantern, but not much brighter than that. I have no idea what this translates to in lumens for a 360 degree beam, but would be interested to find out.
Harder to test I would imagine as well, since the lantern won’t fit many DIY lumens test rigs, and would need a sphere, right?
Yeah, I think we’ve both got the same idea. I might not have been clear enough though. I think the lowest amount of light that the FET can do will NOT be as low as the classic moonlight levels but WILL certainly be low enough for lantern use.
For this we would need anorher MCU like Attiny 84
I had already to remove Indicator LED output for linear CC regulation
R1/2 Volk age divider for LVP
2 FET channels
Enable for rhe CC OPAs and powerbank
@stereodude, it is actually going to be using a linear FET instead of 7135s.
This allows for no PWM, perfect constant current allowing for greater efficiency of the efficiency, and no parasitic inefficiencies coming from PWMing 7135s.
Can someone explain to me how burning the extra voltage above Vf in a FET instead of a 7135 is going to gain efficiency? What are the switching losses in PWM’ing a 7135? The proposed circuit basically uses a FET as a varistor. It’s 2018 and we’re back to using current limiting resistors?
Why isn’t there a true constant current boost circuit? A 1S4P or 2S2P battery config and a two 4 LEDs strings would operate in boost regardless of the battery voltage. This would give constant brightness, ensure each LED gets the same current, and should have greater overall efficiency than just throwing away power in a FET turning it into heat.
Thanks Lexel for designing the driver. It looks good. I hope your hand is doing well. Now about that question from The_Driver.
The_Driver wrote:
Lexel, what is the lowest possible current with that FET driver?
Lexel wrote:
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
Lexel, you know better than me for sure, because I know zero. But I do know that the led4power drivers have a separate channel for moon mode that uses only a resistor and doesn’t use the FET at all, to get a low enough output. Unless you’ve done something led4power couldn’t/didn’t do to get lower output from the FET, it might not be low enough for some people. For me, there probably isn’t any need for an actual moon or firefly level mode. This is a lantern, with light shining in all directions, not a flashlight with the beam concentrated in one direction.
I agree, no additional moonlight mode is needed. Still, it’s interesting to see how low it will go.
@stereodude, it is actually going to be using a linear FET instead of 7135s.
This allows for no PWM, perfect constant current allowing for greater efficiency of the efficiency, and no parasitic inefficiencies coming from PWMing 7135s.
Can someone explain to me how burning the extra voltage above Vf in a FET instead of a 7135 is going to gain efficiency? What are the switching losses in PWM’ing a 7135? The proposed circuit basically uses a FET as a varistor. It’s 2018 and we’re back to using current limiting resistors?
Why isn’t there a true constant current boost circuit? A 1S4P or 2S2P battery config and a two 4 LEDs strings would operate in boost regardless of the battery voltage. This would give constant brightness, ensure each LED gets the same current, and should have greater overall efficiency than just throwing away power in a FET turning it into heat.
I have to agree.
To play devils advocate:
Part of the reason may be the costs and complexity, though. Getting the boost driver right would require multiple revisions, especially to integrate it into a firmware like Andruil. Sure, there are dedicated smps ICs out there, but that increases the BOM and manufacturing effort.
For those who really care about such things, the BLF designs are all made to be easily modded, which many will do.
Part of the reason may be the costs and complexity, though. Getting the boost driver right would require multiple revisions, especially to integrate it into a firmware like Andruil. Sure, there are dedicated smps ICs out there, but that increases the BOM and manufacturing effort.
For those who really care about such things, the BLF designs are all made to be easily modded, which many will do.
I don’t know if it would make the driver cost more, but I put that into the so what category. It wouldn’t be a lot. It is supposed to be the ultimate lantern right?
I don’t think it would require very many revisions. A prove out of the design should be all that’s necessary. I hope the design gets a prove out before they make the lights no matter what the design is.
@stereodude, it is actually going to be using a linear FET instead of 7135s.
This allows for no PWM, perfect constant current allowing for greater efficiency of the efficiency, and no parasitic inefficiencies coming from PWMing 7135s.
Can someone explain to me how burning the extra voltage above Vf in a FET instead of a 7135 is going to gain efficiency? What are the switching losses in PWM’ing a 7135? The proposed circuit basically uses a FET as a varistor. It’s 2018 and we’re back to using current limiting resistors?
Why isn’t there a true constant current boost circuit? A 1S4P or 2S2P battery config and a two 4 LEDs strings would operate in boost regardless of the battery voltage. This would give constant brightness, ensure each LED gets the same current, and should have greater overall efficiency than just throwing away power in a FET turning it into heat.
The FET based linear driver is more efficient in all modes except the max mode because the LEDs are actually being driven at a lower current. LEDs become much more efficient with less current. A 7135 based driver always drives LEDs at the set current, so they have identical effeiciency in all modes.
A boost driver would be better though, I agree, because the LEDs in the lantern are not driven with high currents. This their VFS are rather low. FET vased linear drivers are good for medium to high currents.
7135s removed
CC regulated without PWM added LDOmadded
indicator Led removed for voltage divider
Wow. I’m up for that one!
Amazing work on this! ( i just got home form ym few days away trip)
This looks like the driver that will be the one to run the BLF LT1 lantern. Just curious, for those who wish to mod the maximum lantern outputs, is “R1” the resistor that will regulate the maximum output? ( meaning simply swapping out that resistor with a different ohm value will change the overall output/amp draw?
—
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
yep, 1S4P as the same configuration for the Q8, which in this case with the lower maximum amp draws it can run on even one 18650 or four.
It’s not constant current regulated. It’s regulated (by throwing away excess voltage/power) until the battery voltage drops below Vf + the Rdson * current. At which point it is no longer regulated.
This lantern is crying out for a boost drivers and series strings of 4 LEDs.
The FET based linear driver is more efficient in all modes except the max mode because the LEDs are actually being driven at a lower current. LEDs become much more efficient with less current. A 7135 based driver always drives LEDs at the set current, so they have identical effeiciency in all modes.
Theoretically yes. Maybe… You’re only saving switching losses. Nearly all the losses or gains in efficiency at varying current levels are due to heating of the die. The die heating at 175mA vs. 350mA with a 50% duty and a reasonably fast PWM will be virtually identical meaning there is no efficiency loss/gain in the LED itself. It’s only the switching losses of the PWM.
I’ve yet to see anyone quantify the switching losses, so for all I know someone is chasing a sub 1% gain.
I think it well be more expensive than the Q8. The design is more complicated.
Project Excalibur - Next Generation LED Thrower (UPDATE 2018-01-15: 1.7Mcd)
Portable Thrower Comparison
Interested in at least 2
@The_Driver, I do think it’s going to hit 40$.
Even though we are using a more complicated driver circuit and 8 LEDs, Samsung LH351Ds are much cheaper when bought in bulk than Cree LEDs, so that should balance out.
It also needs less thermal mass since it will absolutely never exceed 1000 lumens except if modded, so less metal is needed.
I do think it’s going to be 40$.
My very own high current Beryllium Copper springs Gen 3:
http://budgetlightforum.com/node/67401
Liitokala Aliexpress Stores Battery Fraud: http://budgetlightforum.com/node/60547
Two total, two more?
PocketSammich wrote: I don’t need this, but I want it. Please sign me up.
Are we set on the LEDs?
R9 values and BBL? Is the light going to be spectacular?
Under 40$, or under 50$ shipped at least seems decent. I hope the interest will be a lot more if it is really that inexpensive.
At that price point I think I would like to reserve an additional 2, putting me at 3 total.
@stereodude, it is actually going to be using a linear FET instead of 7135s.
This allows for no PWM, perfect constant current allowing for greater efficiency of the efficiency, and no parasitic inefficiencies coming from PWMing 7135s.
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
Fitting it under 40€ or 39,99€ with shipping, means no import taxes in many countries. That means the light is 39,99 to the door. A 41€ light with tax is more than 55€ to the door.
40€ = 46$
They should charge a few extra bugs.
I don’t want an manufacturer to make loss, like Lumintop on the first round of the GT.
For Germany it’s 26 Euro and a few cents to slip under taxation.
And if I must pay a tax, I am OK with that.
In Poland the limit is €22 for purchases and €45 for gifts.
All Chinese imports are „gifts“.
Please sign me up for 2 lights
It is a pity there is no LED choice for higher R9 and CRI value.
Thanks Lexel for designing the driver. It looks good. I hope your hand is doing well. Now about that question from The_Driver.
Lexel, you know better than me for sure, because I know zero. But I do know that the led4power drivers have a separate channel for moon mode that uses only a resistor and doesn’t use the FET at all, to get a low enough output. Unless you’ve done something led4power couldn’t/didn’t do to get lower output from the FET, it might not be low enough for some people. For me, there probably isn’t any need for an actual moon or firefly level mode. This is a lantern, with light shining in all directions, not a flashlight with the beam concentrated in one direction.
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
The lighted switch on a Q8 (and probably this lantern) is bright enough for some purposes. Brighter than firefly, lower than moonlight.
What moonlight in a flashlight means to me is enough to find your way around a room or search for something with night adapted eyes, without the spill disturbing sleepers.
In a lantern this is not a practical aim, as if bright enough to light the room for searching, it is maybe too bright to wave around without disturbing sleepers. In a lantern I think the lowest setting (in warm tints) should enable a sleeper to wake up and immediately grab keys/glasses/flashlight/phone etc left lying around the lantern, but not much brighter than that. I have no idea what this translates to in lumens for a 360 degree beam, but would be interested to find out.
Harder to test I would imagine as well, since the lantern won’t fit many DIY lumens test rigs, and would need a sphere, right?
Beam me up!
I guess I’ll put WhitedragonBC down for 1 more, total of 2, 2nd number 962 on the interest list.
lexvegas added two more at 960, 961 on the interest list.
NuggetMcNugget added at 963 on the interest list.
PocketSammich wrote: I don’t need this, but I want it. Please sign me up.
Look like we can hit 1K order for this light.
Yeah, I think we’ve both got the same idea. I might not have been clear enough though. I think the lowest amount of light that the FET can do will NOT be as low as the classic moonlight levels but WILL certainly be low enough for lantern use.
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
For this we would need anorher MCU like Attiny 84
I had already to remove Indicator LED output for linear CC regulation
R1/2 Volk age divider for LVP
2 FET channels
Enable for rhe CC OPAs and powerbank
[Reviews] Miboxer C4-12, C2-4k+6k, C2, C4 / Astrolux K1, MF01, MF02, S42, K01, TI3A / BLF Q8 / Kalrus G35, XT11GT / Nitefox UT20 / Niwalker BK-FA30S / Sofirn SF36, SP35 / Imalent DM21TW / Wuben I333 / Ravemen PR1200 / CL06 lantern / Xanes headlamp
[Mods] Skilhunt H03 short / Klarus XT11GT, XT12GTS / Zebralight SC50+ / Imalent DM21TW / colorful anodisation
[Sale]
Drivers: overview of sizes and types
DD+AMC based drivers Anduril or Bistro OTSM 12-24mm, S42, 24-30mm L6, Q8, MF01(S), MT03, TN42
Anduril or Bistro 8A buck driver for 20-30mm, MF01/02/04, TN40/42, Lumintop GT, MT09R
UVC and UVC+UVA drivers
programming key
Remote switch tail DD board with FET
Aux boards:
Emisar D1, D1S, D4, D4S, D18, Lumintop FW3A, Fireflies ROT66, Astrolux MF01, Tail boards like S2+
Why isn’t there a true constant current boost circuit? A 1S4P or 2S2P battery config and a two 4 LEDs strings would operate in boost regardless of the battery voltage. This would give constant brightness, ensure each LED gets the same current, and should have greater overall efficiency than just throwing away power in a FET turning it into heat.
I agree, no additional moonlight mode is needed. Still, it’s interesting to see how low it will go.
Project Excalibur - Next Generation LED Thrower (UPDATE 2018-01-15: 1.7Mcd)
Portable Thrower Comparison
I have to agree.
To play devils advocate:
Part of the reason may be the costs and complexity, though. Getting the boost driver right would require multiple revisions, especially to integrate it into a firmware like Andruil. Sure, there are dedicated smps ICs out there, but that increases the BOM and manufacturing effort.
For those who really care about such things, the BLF designs are all made to be easily modded, which many will do.
I don’t think it would require very many revisions. A prove out of the design should be all that’s necessary. I hope the design gets a prove out before they make the lights no matter what the design is.
The FET based linear driver is more efficient in all modes except the max mode because the LEDs are actually being driven at a lower current. LEDs become much more efficient with less current. A 7135 based driver always drives LEDs at the set current, so they have identical effeiciency in all modes.
A boost driver would be better though, I agree, because the LEDs in the lantern are not driven with high currents. This their VFS are rather low. FET vased linear drivers are good for medium to high currents.
Project Excalibur - Next Generation LED Thrower (UPDATE 2018-01-15: 1.7Mcd)
Portable Thrower Comparison
Amazing work on this! ( i just got home form ym few days away trip) This looks like the driver that will be the one to run the BLF LT1 lantern.
Just curious, for those who wish to mod the maximum lantern outputs, is “R1” the resistor that will regulate the maximum output? ( meaning simply swapping out that resistor with a different ohm value will change the overall output/amp draw?
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
yep, 1S4P as the same configuration for the Q8, which in this case with the lower maximum amp draws it can run on even one 18650 or four.
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
This lantern is crying out for a boost drivers and series strings of 4 LEDs.
I’ve yet to see anyone quantify the switching losses, so for all I know someone is chasing a sub 1% gain.
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