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

[HKSJOSHUA]

I’m interested depending on price point and can not have visible pwm at all

[cu42]

Will the price be lower than originally projected since there are so many sold?

[djozz]

@cu42

Will the price be lower than originally projected since there are so many sold?

That is a valid argument, but another valid argument: perhaps Sofirn went with so many extra features than originally projected because so many will be sold, keeping the price steady.

[HKSJOSHUA]

Hmm maybe I’ll use my diesel powered coleman instead operating cost is minimal 1.5 gallons a year

[jigsaw]

@HKSJOSHUA\_

Hmm maybe I’ll use my diesel powered coleman instead operating cost is minimal 1.5 gallons a year

Yes, maybe you should. This lantern isn’t for everyone.

[iamlucky13]

@HKSJOSHUA\_

I’m interested depending on price point and can not have visible pwm at all

The hardware and firmware both have similarities to other lights that are popular around BLF, such as the FW3A, the Q8, and all of the Emisar lights.

Those lights all use PWM, but at such a high frequency that I’m not aware of anybody reporting it to be visible.

The price has been estimated at $50, but is not confirmed yet.

[HKSJOSHUA]

Well suppose it is around 50 bucks then I may buy two, would be worth it not having to worry about a conventional lantern globe breaking or mantles getting broken

[Relampago]

With the advent of solar, this is an easy choice for me. I purchased the eceen that everyone recommended and I found that it works just as described. It was a bit refreshing considering I had purchased cheap alternatives before and none ever charged items effectively. This one was instantly working.

[Phlogiston]

@DBSAR

@Phlogiston

Just thought of a question:

Will maximum light output be at full power and 4000K, i.e. when both sets of LEDs are on equally at full blast?

Toykeeper has programed the LT1 Andruil firmware to balance the output across the tint ramping, so it should be close the same from the 3000K to the 5000K range.

Thank you :+1:

That suggests the lantern may be most efficient at 4000K, since it’ll be at full light output, but running both sets of LEDs at a lower power, more efficient level.

I’m going to be spending a lot of time playing with this thing

[Aaron93]

Are 2700k emitters still a possibility for the production version?

[SIGShooter]

Here are the additions for this week. Files linked in post #1 have been updated.

Thanks

1803 bquinlan
1804 Johm
1805 Funtastic
1806 Funtastic
1807 wholphin
1808 xevious
1809 lovetheguitar
1810 Ratus
1811 wolfstyle
1812 minim
1813 AndyMac2272
1814 Just a Guy
1815 Just a Guy
1816 ikkentobi
1817 Aaron93
1818 bassoverflow
1819 pcywmf
1820 MascaratumB
1821 Man Without Shadow
1822 tehmatt
1823 tehmatt
1824 rahdi
1825 henryj3223
1826 Dioda
1827 Thrust84
1828 Wazaloob
1829 piyoman
1830 kase
1831 Hobo
1832 toobadorz
1833 HKSJOSHUA_

[Kimber55]

Interested!

[scottb7862]

I’m in!!! Please

[DavidEF]

@Phlogiston

That suggests the lantern may be most efficient at 4000K, since it’ll be at full light output, but running both sets of LEDs at a lower power, more efficient level.

Yes, that should be true.

@Phlogiston

I’m going to be spending a lot of time playing with this thing

That should be true too! :partying_face:

[DBSAR]

@Aaron93

Are 2700k emitters still a possibility for the production version?

They appear to be the 2700K, (i haven’t got conformation) the difference between the 2700K and 3000K is a slightly yellower warmer tint.

[JoeRodge]

@Relampago

With the advent of solar, this is an easy choice for me. I purchased the eceen that everyone recommended and I found that it works just as described. It was a bit refreshing considering I had purchased cheap alternatives before and none ever charged items effectively. This one was instantly working.

Where can I find this panel you speak of?

[iamlucky13]

@Phlogiston

That suggests the lantern may be most efficient at 4000K, since it’ll be at full light output, but running both sets of LEDs at a lower power, more efficient level.

Since the final driver is based on a single channel of 7135’s for each set of LED’s, the forward current is the same regardless of ramp position. Although PWM lowers the average current, and therefore perceived brightness, the efficacy is primarily determined by current during the on phase of the PWM.

Increased temperature also reduces efficacy, but since the emitters are sharing an MCPCB, and running at the same total average current regardless of whether it is one bank at 100% or both banks at 50%, the temperature difference between the scenarios will be very small.

Maukka did a test with the Emisar D4 a while back that happens to be relevant. At max 7135, he measured almost exactly the same efficacy as at a level slightly over half the same output:

TK's Emisar D4 review

Here’s just to verify what is obvious. Efficacy stays exactly the same on lower output within the 7135 range. Little nicks on the orange graph is me bumping into the setup while cleaning… [image]

So I suggest not worrying about efficacy too much, and just choose the color temperature appropriate for the situation. With 4 cells, you will get a lot of runtime regardless of the tint.

[DBSAR]

@JoeRodge

@Relampago

With the advent of solar, this is an easy choice for me. I purchased the eceen that everyone recommended and I found that it works just as described. It was a bit refreshing considering I had purchased cheap alternatives before and none ever charged items effectively. This one was instantly working.

Where can I find this panel you speak of?

here: https://www.amazon.com/dp/B01BBCVIBK/ref=twister_B01BBCVI4C?\_encoding=UTF8&psc=1

[contactcr]

@DavidEF

@Phlogiston

That suggests the lantern may be most efficient at 4000K, since it’ll be at full light output, but running both sets of LEDs at a lower power, more efficient level.

Yes, that should be true.

Kind of. The higher CCT LED is probably several flux bins higher so it probably wont be right in the middle if that’s what we are implying with 4000K.

[DavidEF]

@iamlucky13

@Phlogiston

That suggests the lantern may be most efficient at 4000K, since it’ll be at full light output, but running both sets of LEDs at a lower power, more efficient level.

Since the final driver is based on a single channel of 7135’s for each set of LED’s, the forward current is the same regardless of ramp position. Although PWM lowers the average current, and therefore perceived brightness, the efficacy is primarily determined by current during the on phase of the PWM.

Increased temperature also reduces efficacy, but since the emitters are sharing an MCPCB, and running at the same total average current regardless of whether it is one bank at 100% or both banks at 50%, the temperature difference between the scenarios will be very small.

Maukka did a test with the Emisar D4 a while back that happens to be relevant. At max 7135, he measured almost exactly the same efficacy as at a level slightly over half the same output:
TK's Emisar D4 review - #1003 by maukka

So I suggest not worrying about efficacy too much, and just choose the color temperature appropriate for the situation. With 4 cells, you will get a lot of runtime regardless of the tint.

Yeah, but you’re forgetting one simple thing. If all the emitters are sharing current equally, it will be more efficient than if only half of them are, whether or not there is PWM involved. IIRC, TK already said the light gets brighter in the middle of the ramping between CCT groups, so that pretty much confirms this. Then, TK tweaked the settings to reduce the current at the middle, in order to keep the brightness level the same throughout the CCT ramp. That means you will literally get the same amount of light for less current when sitting in the middle of the CCT ramp. I guess I could be remembering wrong, but I thought that’s what she said.