Any idea what voltage the charge circuit outputs with no cells installed? It would be nice if it was pretty close to the forward voltage of the LEDs so the 7135s wouldn’t have to burn off too much voltage
Good question, so i tested the LT1 with the battery tube removed, plugged in a USB-C cord to a Samsung S9 wall fast charger, using my Fluke DM, i got a open voltage of 4.20 volts at the batter contact ring & ground on the driver. on maximum mode, (with 5-7135 AMCs enabled and tint mixed to around 4000K, the voltage at the ring was 3.76 volts. My only concern is the constant amp load on the TP5100 would over load the chip on high running constantly ( with all 7-AMCs enabled especially) but either Lexel or Toykeeper would be better to answer that question, if the TP5100 can sustain a 1.5+ amp constant static load running the lantern with no batteries as a regulated power supply chip, ( which i do not know if the TP5100 was designed to handle being a power supply regulator, (as opposed to its original intent as a Lithium Ion charging regulator chip.
The TP5100 has no problem handling 1,5A passively.
However, going higher needs a heatsink, as it gets too hot otherwise.
That’s from my testing anyway.
I don’t have any personal data, just looking at the data sheet, its programmable from 0.1 to 2.0A output. 1.5A should be no problem, likely 2A is not either. Its rated to 85C ambient temperature, 120C junction temp, so seems like 2A wouldn’t be a problem, even if the part feels hot.
Has one of our team members tested, how bright the lantern gets with different amounts of 7135s connected ? Related to that it would be interesting to know the power consumption at different brightness levels.
Each 7135 chip allows 350mA at its highest mode. So the power consumption at the brightest mode with various amounts of 7135 chips is:
- 0.35 A
- 0.70 A
- 1.05 A
- 1.40 A
- 1.75 A
- 2.10 A
- 2.45 A
This may vary by ~5% or so depending on the exact color temperature used, because the power usage isn’t completely flat while changing tints. But it’s reasonably close.
So far i reduced it from 7-7135s per channel to 5-7135s per channel, on maximum mode it was slightly dimmer, but the amp draw decreased, thus the run time will increase. (but i have not tested with individual chips disabled versus run times. With 5 chips per channel, it produces plenty of light on high, and is brighter than most all my other modified LED lanterns, with many times the run time duration.
:+1: With that list of amp-loads, its possible to calculate an average run time for a given set of cells depending on their capacity.
I’ve been keeping an eye on this for a while.
Sign me up for 1 lantern please!
I know that every chip gives you max. 350mA. I wanted to know how much power the lantern consumes at e.g. 50lm/300lm/1000lm. And of course what the maximum brightness is.
There are 150 brightness steps, with full details in the code. With so many steps, and 7 different amounts of 7135 chips available, it’s not really feasible to publish output and runtime data for every combination.
If it makes things any simpler, the default stepped ramp configuration has 5 steps from level 10/150 to level 150/150. These run at PWM levels 5, 31, 77, 150, and 255. So the power levels in percent, at these default five steps, are (approximately):
- 1.96%
- 12.2%
- 30.2%
- 58.8%
- 100%
For example, with 5x7135 chips enabled, the approximate power and runtime is…
- 34 mA (17 days)
- 213 mA (2.74 days)
- 528 mA (26.5 hours)
- 1030 mA (13.6 hours)
- 1750 mA (8 hours)
I’m Interested
Count me in - very interested!
I’d like to get in on the group buy
I’m interested! Count me in
Any updates so far? I’m hoping to have one in my hands beginning july or is that just wishfull thinking?
I’m interested. Sign me up for 1 piece.
Thanks
just wishfull thinking IMO, but keep hope alive.
I hope I can get one before the next hurricane comes to FL.
I hope to get it soon so I can tinker outside on cool summer nights!