I wish the lantern project would be a sort of addon to the Q8, I am sure with a proper reflective cone shaped on the top with a milky cylinrdical diffusor the light pattern would be great, without moving the LED on the top
Have tested more of the diffuser designs that I wished to count, (and abandoned all of them) some are ok, but not nearly as beneficial as a down-firing design for lantern use to minimizes eye-glare from the angles that most lanterns will be used. As Miller mentioned it’s a question that been answered many times. One example is i have a head i built to fit on top of a BLF SD-10 ( and other lights with the same sized head) that is very close to your drawing, but like most all types of flashlight diffuser heads of that style, sens eye-stinging glare to the eyes when carried like a lantern by a lanyard, or on a table that is lower than your horizontal plane of view. ( example, when resting on a low table beside chairs at a campsite, or a coffee table, when you look down at it you get the direct view of the LED and its piercing glare. ( which is even worse with the colder tints higher than 3700K.
—
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
Indeed, there is tons of space above the driver in the mid-section to add the charger & USB bank electronics.
What about the option to add an optional wireless remote control&status modul (bluetooth) there?
Bluetooth remotes would just drive the price way to high, and to complex and a feature that many would never use. I have a couple remote control lanterns and the Manker Godmes Bluetooth flashlight. A feature rarely used.
—
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
Driver progress! We are still in design stage, so a few things will probably change before it is all said and done. But I am close to ordering boards and parts for a prototype.
Basic specifications for the stock setup:
Constant current drive to LED (no PWM), 0 to 1 A (can be bumped up to about 2 A with a resistor change)
Output can be adjusted in firmware with 4 mA resolution (255 steps over the 1 A range)
Firmware is TK’s domain and will probably be a flavor of Anduril
2 A charging via a micro USB port. Cells over-voltage protection. Proper charging profile with 128 mA pre-charge, 256 mA charge termination. 4.208 V termination voltage with 0.5% accuracy.
Power-bank functionality: 2.1 A output for a phone or tablet via a standard USB port
90%+ efficiency for charging and power-bank output buck/boost circuits.
Bottom half is the LED driver, top half the buck charger and 5 V booster.
The board is 46 mm diameter ‘SRK’ format. It needs a brass contact ring for the cells+ contact, isolated from the board in the top quadrant. This is an unfortunate necessity due to the power-bank chip’s thermal requirements.
USB ports should be through-hole type for the sake of durability. Not so easy if we want to keep the 46 mm SRK format board. So at the moment they will be on a separate board, together with the diagnostic LED for power bank functionality. The bunch of small wire pads for USB interfacing may eventually get reworked to a small connector.
U3 is a precision DC opamp and does the closed-loop current control for the LED driver (driving a meaty FET in linear mode). A sense resistor creates the feedback signal. The MCU (a venerable tiny85) generates the reference signal. Driver dropout should be < 150 mV, giving regulated control down to about 3.2 V.
U4 is an all-in-one power-bank chip from TI’s BQ24 or BQ25 series (currently looking at the BQ25895, it is also used in the higher end Xiaomi power banks).
Driver progress! We are still in design stage, so a few things will probably change before it is all said and done. But I am close to ordering boards and parts for a prototype.
Basic specifications for the stock setup:
Constant current drive to LED (no PWM), 0 to 1 A (can be bumped up to about 2 A with a resistor change)
Output can be adjusted in firmware with 4 mA resolution (255 steps over the 1 A range)
Firmware is TK’s domain and will probably be a flavor of Anduril
2 A charging via a micro USB port. Cells over-voltage protection. Proper charging profile with 128 mA pre-charge, 256 mA charge termination. 4.208 V termination voltage with 0.5% accuracy.
Power-bank functionality: 2.1 A output for a phone or tablet via a standard USB port
90%+ efficiency for charging and power-bank output buck/boost circuits.
The board is 46 mm diameter ‘SRK’ format. It needs a brass contact ring for the cells+ contact, isolated from the board in the top quadrant. This is an unfortunate necessity due to the power-bank chip’s thermal requirements.
USB ports should be through-hole type for the sake of durability. Not so easy if we want to keep the 46 mm SRK format board. So at the moment they will be on a separate board, together with the diagnostic LED for power bank functionality. The bunch of small wire pads for USB interfacing may eventually get reworked to a small connector.
U3 is a precision DC opamp and does the closed-loop current control for the LED driver (driving a meaty FET in linear mode). A sense resistor creates the feedback signal. The MCU (a venerable tiny85) generates the reference signal. Driver dropout should be < 150 mV, giving regulated control down to about 3.2 V.
U4 is an all-in-one power-bank chip from TI’s BQ24 or BQ25 series (currently looking at the BQ25895, it is also used in the higher end Xiaomi power banks).
Beautiful work DEL! I will update the OP with your work on the driver for the lantern.
—
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
I know it would be bunches more expensive to do, but if a 4-layer board were possible, all the ground planes and thermals could be re-routed away from the ‘center’ ring in the middle layers, leaving us with a ‘standard’ back layer with ‘standard’ v+ and v- rings.
Edit:OSH Park doesn’t support ‘blind’ vias, so that would make re-routing tricky, even with 4-layer boards. But, if we could get it done, I think it would be worth it, even if the cost goes up a bit.
—
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
Ah and with this design, of a brass ring is soldered on it will be isolated from north?
If so, those vias from the gnd plane of U4 should be masked, right?
Those are thermal vias, not supposed to be masked. Not sure I would trust just masking either. A short there would be spectacular. The ring would need to be relieved on the back so that it ‘hovers’ in that area. The area should also be sealed up so that a metal shaving or similar cannot get in. Would have been much simpler without the power-bank stuff .
We will have to see what the manufacturer can work with, ditto for the off-board USB ports.
Ah and with this design, of a brass ring is soldered on it will be isolated from north?
If so, those vias from the gnd plane of U4 should be masked, right?
Those are thermal vias, not supposed to be masked. Not sure I would trust just masking either. A short there would be spectacular. The ring would need to be relieved on the back so that it ‘hovers’ in that area. The area should also be sealed up so that a metal shaving or similar cannot get in. Would have been much simpler without the power-bank stuff .
We will have to see what the manufacturer can work with, ditto for the off-board USB ports.
Well, I’m not sure I would trust ‘just’ masking either, but I’d trust it a lot more than ‘not’ masking! If we could get a 4-layer board with blind vias through three layers, but not through the back layer, to spread the heat side-ways to a less dangerous place, that would make me feel better.
—
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
What about moving the U4 to be within the inner circle? You’d still have to make a gap in the v+ ring to let the thermal plane thru, but it could be masked and safely bridged across with the brass ring. Is that possible or am I dreaming?
—
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
If possible, it would be great to have a modern firmware, like Narsil, or Anduril, if it’s ready in time. I know most people will probably want the UI to be simple. So the default should be set to a simple mode group. But, for the rest of us, it will be nice knowing we can change to something more interesting. Especially for those of us who are still not flashing our own yet.
I for one, am REALLY wanting the lightening mode with this lantern!
It’ll mostly depend on what DBSAR wants, but for now I’m planning on porting Anduril to it and adjusting the default settings. So you’ll most likely get lightning storm mode, and candle flicker mode, and maybe other stuff. If it has a switch LED it’ll be possible to set the switch LED to high/low/off when the main emitter is off.
This also means you can have a mode group or ramping, and the mode group can be whatever you want… as long as you want 2 or more evenly-spaced levels in sorted order. Want 3 steps? Use 3 steps. Want 18 steps? Use 18 steps. Don’t like moon? Raise the floor. Etc.
Thermal regulation likely won’t even be relevant, so it’s not waiting on me to tweak that for better behavior. Mostly, I’m just waiting for hardware so I can add support for it. It’ll have to use a pin for voltage measurement like on older BLF drivers, and the power control is a little different, and it’ll need ramp adjustments and stuff. But that shouldn’t be hard.
Please add me as well, thanks!
Looks like this would be useful…please add me to the list for one.
Have tested more of the diffuser designs that I wished to count, (and abandoned all of them) some are ok, but not nearly as beneficial as a down-firing design for lantern use to minimizes eye-glare from the angles that most lanterns will be used. As Miller mentioned it’s a question that been answered many times. One example is i have a head i built to fit on top of a BLF SD-10 ( and other lights with the same sized head) that is very close to your drawing, but like most all types of flashlight diffuser heads of that style, sens eye-stinging glare to the eyes when carried like a lantern by a lanyard, or on a table that is lower than your horizontal plane of view. ( example, when resting on a low table beside chairs at a campsite, or a coffee table, when you look down at it you get the direct view of the LED and its piercing glare. ( which is even worse with the colder tints higher than 3700K.
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
Bluetooth remotes would just drive the price way to high, and to complex and a feature that many would never use. I have a couple remote control lanterns and the Manker Godmes Bluetooth flashlight. A feature rarely used.
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
All im looking for in a lantern is:
- 4×18650 or 4×26650 (in parallel). Would be sweet if the battery compartment would be big enough to fit 26650s.
- UBS charging port to charge cell phone etc.
- Modes ranging from 5 lumens to around 500 lumens.
…………Just personal preferences
Please put me down as interested!
Please add me to the list
How did I do that?
I guess by pressing the letter b ?
The Eneloop 2005-2021 info thread
Im interested in seeing this going to become the first BLF-special lantern. Curious how this is going to look like.
The Eneloop 2005-2021 info thread
But usually I know that I did what I did. It’s the not knowing that makes me wonder.
The Eneloop 2005-2021 info thread
What? Why? This is BLF! Let the unnecessary posts stay I say!
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
I’m interested as well.
Driver progress! We are still in design stage, so a few things will probably change before it is all said and done. But I am close to ordering boards and parts for a prototype.
Basic specifications for the stock setup:
Bottom half is the LED driver, top half the buck charger and 5 V booster.
The board is 46 mm diameter ‘SRK’ format. It needs a brass contact ring for the cells+ contact, isolated from the board in the top quadrant. This is an unfortunate necessity due to the power-bank chip’s thermal requirements.
USB ports should be through-hole type for the sake of durability. Not so easy if we want to keep the 46 mm SRK format board. So at the moment they will be on a separate board, together with the diagnostic LED for power bank functionality. The bunch of small wire pads for USB interfacing may eventually get reworked to a small connector.
U3 is a precision DC opamp and does the closed-loop current control for the LED driver (driving a meaty FET in linear mode). A sense resistor creates the feedback signal. The MCU (a venerable tiny85) generates the reference signal. Driver dropout should be < 150 mV, giving regulated control down to about 3.2 V.
U4 is an all-in-one power-bank chip from TI’s BQ24 or BQ25 series (currently looking at the BQ25895, it is also used in the higher end Xiaomi power banks).
My OSH-Park boards
Add a second for me, thanks
BLF Member Map, add yourself
My 7th Annual contest entry My 6th Annual contest entry My 5th Annual contest entry My 4th Annual contest entry
My DBSAR inspired SRK lantern hand made mod
Nice DEL!
Makes me dizzy to just see the board, and you designed it and actually know why it all is as it is…
It is done when it is done

How my BLF Specials generally work, please read before asking Qs
The Q8, Exciting a groupbuy for a Premium BLF special high lumens soda can light!
The GT, A BLF special GIGA thrower
The FW3A, a TLF BLF special small, elegant, powerful triple
Lithium Ion safety 101 important read
Sorry grammarlovers, I am a real King Typo.
Ah and with this design, of a brass ring is soldered on it will be isolated from north?
It is done when it is done

How my BLF Specials generally work, please read before asking Qs
The Q8, Exciting a groupbuy for a Premium BLF special high lumens soda can light!
The GT, A BLF special GIGA thrower
The FW3A, a TLF BLF special small, elegant, powerful triple
Lithium Ion safety 101 important read
Sorry grammarlovers, I am a real King Typo.
That sounds and looks like an über-
driver DEL, so PWM-less smooth dimming plus charger plus powerbank!
link to djozz tests
Beautiful work DEL! I will update the OP with your work on the driver for the lantern.
That Canadian flashlight guy & Lantern Guru -Den / DBSARlight
If so, those vias from the gnd plane of U4 should be masked, right?
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
I know it would be bunches more expensive to do, but if a 4-layer board were possible, all the ground planes and thermals could be re-routed away from the ‘center’ ring in the middle layers, leaving us with a ‘standard’ back layer with ‘standard’ v+ and v- rings.
Edit: OSH Park doesn’t support ‘blind’ vias, so that would make re-routing tricky, even with 4-layer boards. But, if we could get it done, I think it would be worth it, even if the cost goes up a bit.
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
Those are thermal vias, not supposed to be masked. Not sure I would trust just masking either. A short there would be spectacular. The ring would need to be relieved on the back so that it ‘hovers’ in that area. The area should also be sealed up so that a metal shaving or similar cannot get in. Would have been much simpler without the power-bank stuff
.
We will have to see what the manufacturer can work with, ditto for the off-board USB ports.
My OSH-Park boards
Well, I’m not sure I would trust ‘just’ masking either, but I’d trust it a lot more than ‘not’ masking! If we could get a 4-layer board with blind vias through three layers, but not through the back layer, to spread the heat side-ways to a less dangerous place, that would make me feel better.
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
What about moving the U4 to be within the inner circle? You’d still have to make a gap in the v+ ring to let the thermal plane thru, but it could be masked and safely bridged across with the brass ring. Is that possible or am I dreaming?
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
Please add me to the list for one. Looks really good to me!
Will the main LED-Driver be a buck-driver for maximum efficiency?
I noticed I’m not on the interest list… but I’m doing the firmware so I should probably be on the list. Miller?
It’s a linear FET, not a buck driver. Runtimes should still be very long though.
It’ll mostly depend on what DBSAR wants, but for now I’m planning on porting Anduril to it and adjusting the default settings. So you’ll most likely get lightning storm mode, and candle flicker mode, and maybe other stuff. If it has a switch LED it’ll be possible to set the switch LED to high/low/off when the main emitter is off.
This also means you can have a mode group or ramping, and the mode group can be whatever you want… as long as you want 2 or more evenly-spaced levels in sorted order. Want 3 steps? Use 3 steps. Want 18 steps? Use 18 steps. Don’t like moon? Raise the floor. Etc.
Thermal regulation likely won’t even be relevant, so it’s not waiting on me to tweak that for better behavior. Mostly, I’m just waiting for hardware so I can add support for it. It’ll have to use a pin for voltage measurement like on older BLF drivers, and the power control is a little different, and it’ll need ramp adjustments and stuff. But that shouldn’t be hard.
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