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

11384 posts / 0 new
Last post
The_Driver
The_Driver's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 10/20/2016 - 05:51
Posts: 1450
Location: Germany

I think it well be more expensive than the Q8. The design is more complicated.

WhitedragonBC
WhitedragonBC's picture
Offline
Last seen: 4 months 1 week ago
Joined: 05/17/2014 - 00:42
Posts: 190
Location: California

Interested in at least 2

BlueSwordM
BlueSwordM's picture
Offline
Last seen: 1 month 1 week ago
Joined: 11/29/2017 - 12:34
Posts: 5544
Location: Canada

@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

sbslider
sbslider's picture
Offline
Last seen: 7 hours 2 min ago
Joined: 01/22/2017 - 13:41
Posts: 1637
Location: United States
WhitedragonBC wrote:
Interested in at least 2
sbslider wrote:
WhitedragonBC wrote:
Interested
WhitedragonBC added to the interest list at number 949

Two total, two more?

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

mdeni
mdeni's picture
Offline
Last seen: 1 month 5 days ago
Joined: 08/06/2016 - 05:17
Posts: 271
Location: Europe

Are we set on the LEDs?

R9 values and BBL? Is the light going to be spectacular? Smile

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.

Stereodude
Offline
Last seen: 12 months 3 days ago
Joined: 03/16/2013 - 21:14
Posts: 521
Location: US of A

Lexel wrote:
7135s removed
CC regulated without PWM added
LDOmadded
indicator Led removed for voltage divider
Does this mean it will be constant current regulated? Is it a boost driver with two strings each with 4 LEDs? Is the intent to run the batteries 1S4P?
lexvegas
Offline
Last seen: 11 months 2 weeks ago
Joined: 07/24/2018 - 14:20
Posts: 91
Location: USA

At that price point I think I would like to reserve an additional 2, putting me at 3 total.

BlueSwordM
BlueSwordM's picture
Offline
Last seen: 1 month 1 week ago
Joined: 11/29/2017 - 12:34
Posts: 5544
Location: Canada

@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

mdeni
mdeni's picture
Offline
Last seen: 1 month 5 days ago
Joined: 08/06/2016 - 05:17
Posts: 271
Location: Europe

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$

joechina
Offline
Last seen: 2 hours 14 min ago
Joined: 03/05/2016 - 08:23
Posts: 1444
Location: Germany

BlueSwordM wrote:
@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$.

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.

joechina
Offline
Last seen: 2 hours 14 min ago
Joined: 03/05/2016 - 08:23
Posts: 1444
Location: Germany

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.

Agro
Agro's picture
Online
Last seen: 1 min 24 sec ago
Joined: 05/14/2017 - 11:16
Posts: 6300
Location: Ślōnsk

In Poland the limit is €22 for purchases and €45 for gifts.

mdeni
mdeni's picture
Offline
Last seen: 1 month 5 days ago
Joined: 08/06/2016 - 05:17
Posts: 271
Location: Europe

All Chinese imports are „gifts“. Smile

NuggetMcNugget
NuggetMcNugget's picture
Offline
Last seen: 1 month 2 weeks ago
Joined: 09/16/2015 - 14:39
Posts: 315
Location: Sweden

Please sign me up for 2 lights

mdeni
mdeni's picture
Offline
Last seen: 1 month 5 days ago
Joined: 08/06/2016 - 05:17
Posts: 271
Location: Europe

It is a pity there is no LED choice for higher R9 and CRI value.

DavidEF
DavidEF's picture
Offline
Last seen: 1 week 1 day ago
Joined: 06/05/2014 - 06:00
Posts: 7699
Location: Salisbury, North Carolina, USA

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

Zulumoose
Zulumoose's picture
Offline
Last seen: 6 months 3 weeks ago
Joined: 04/13/2017 - 09:25
Posts: 859
Location: South Africa
Quote:
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?

Beam me up!

sbslider
sbslider's picture
Offline
Last seen: 7 hours 2 min ago
Joined: 01/22/2017 - 13:41
Posts: 1637
Location: United States
sbslider wrote:
WhitedragonBC wrote:
Interested in at least 2
sbslider wrote:
WhitedragonBC wrote:
Interested
WhitedragonBC added to the interest list at number 949

Two total, two more?


I guess I’ll put WhitedragonBC down for 1 more, total of 2, 2nd number 962 on the interest list.
lexvegas wrote:
At that price point I think I would like to reserve an additional 2, putting me at 3 total.

lexvegas added two more at 960, 961 on the interest list.

NuggetMcNugget wrote:
Please sign me up for 2 lights

NuggetMcNugget added at 963 on the interest list.

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

Satan@103TFS
Offline
Last seen: 2 days 3 min ago
Joined: 09/04/2017 - 12:51
Posts: 569

Look like we can hit 1K order for this light. Beer

DavidEF
DavidEF's picture
Offline
Last seen: 1 week 1 day ago
Joined: 06/05/2014 - 06:00
Posts: 7699
Location: Salisbury, North Carolina, USA
Zulumoose wrote:
Quote:
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

Lexel
Lexel's picture
Offline
Last seen: 1 week 6 days ago
Joined: 11/01/2016 - 08:00
Posts: 5895
Location: Germany
DavidEF wrote:
Zulumoose wrote:
Quote:
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
Offline
Last seen: 12 months 3 days ago
Joined: 03/16/2013 - 21:14
Posts: 521
Location: US of A

BlueSwordM wrote:
@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_Driver
The_Driver's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 10/20/2016 - 05:51
Posts: 1450
Location: Germany

DavidEF wrote:
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.

lexvegas
Offline
Last seen: 11 months 2 weeks ago
Joined: 07/24/2018 - 14:20
Posts: 91
Location: USA

Stereodude wrote:
BlueSwordM wrote:
@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.

Stereodude
Offline
Last seen: 12 months 3 days ago
Joined: 03/16/2013 - 21:14
Posts: 521
Location: US of A

lexvegas wrote:
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 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.

The_Driver
The_Driver's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 10/20/2016 - 05:51
Posts: 1450
Location: Germany

Stereodude wrote:
BlueSwordM wrote:
@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.

DBSAR
DBSAR's picture
Offline
Last seen: 6 days 22 hours ago
Joined: 02/11/2013 - 23:28
Posts: 6315
Location: Ontario, Canada

Phlogiston wrote:
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!

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. Smile 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

DBSAR
DBSAR's picture
Offline
Last seen: 6 days 22 hours ago
Joined: 02/11/2013 - 23:28
Posts: 6315
Location: Ontario, Canada
Stereodude wrote:
Lexel wrote:
7135s removed CC regulated without PWM added LDOmadded indicator Led removed for voltage divider
Does this mean it will be constant current regulated? Is it a boost driver with two strings each with 4 LEDs? Is the intent to run the batteries 1S4P?

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

Stereodude
Offline
Last seen: 12 months 3 days ago
Joined: 03/16/2013 - 21:14
Posts: 521
Location: US of A

DBSAR wrote:
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.

Stereodude
Offline
Last seen: 12 months 3 days ago
Joined: 03/16/2013 - 21:14
Posts: 521
Location: US of A

The_Driver wrote:
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.

Pages