Photon Freedom Microlight Runtime

[meeshu]

OK. Just finished recording the runtime for LRI Photon Freedom Microlight.

Light sensor placed 1 foot away from light. Recordings in foot-candles.

Starting brightness was about 42 foot-candles. Recorded for 22 hours.

No apparent light regulation.

Further runtimes for this and other lights are in progress.

For those wanting a bit more detail, I enclose the following image.

 

[dtsoll]

Alrighty, thanks Meeshu!! Doug

 

[ViReN]

Thanks for such a great graph. can i call this as :nana: "semi regulated" :nana:

Now one more request ... try replacing the battery with 1 CR2032 and doing the graphs again. they will be much better as compared with this one. the Light will also last much more and the output wont drop as quickly as it is doing now.

it would be great if both the graphs are put together.

Also, once you are done with this, Imagine what would be the case with 2 CR2032 ....I had requested for this long time back... and in fact it can then be made "LDO" regulated too ... but who listens .. . PhotonLight are you reading this

 

[Sub_Umbra]

Thanks!

 

[vortechs]

Also, once you are done with this, Imagine what would be the case with 2 CR2032 ....I had requested for this long time back... and in fact it can then be made "LDO" regulated too ... but who listens .. . PhotonLight are you reading this

I think a two CR2032 microlight would be a nice offering but I wonder how well the LED can handle the increased voltage and current, since the larger coin cells wouldn't have as much voltage drop when loaded. I suppose I could give it a try with a bare Nichia if I could find 2 fresh CR2032's in my box of batteries.

 

[paulr]

Chanik posted a while back that a 2032 delivers about the same current as a 2016. The Princeton Tec Scout is a small 2-led headlamp using four 2032's, presumably 2 for each led, so you could try your runtime test on one. Btw, what's the fc reading of an Arc AAA?

 

[jar3ds]

thanks for the post!

it has made me more thankful of why i have an arc AAA P on my keychain

 

[this_is_nascar]

Unfortunately, regulation does not seem to be a priority with LRI. They've carried this same philosophy forward into the Proton. On lithium or NiMH, it appears to be semi-regulated, but that's only because of the flat discharge of those types of cells. In fact, none of the LRI products that I've tested have any amount of regulation whatsoever.

 

[ViReN]

if the light is built around 2CR2032, there is a chance to have an Onboard Current LDO with minimum of loss. the light can remain regulated and will have runtime as much as an Arc AAA (if not less) at the same time it would be bright. the energy packed in 2 CR2032 cells is more than 1 AAA by a good margin. To be specific 250 mAh @ 6V (2xCR2032) = 1500 mWh compared with 1000 mAh @ 1.2 V for NiMH = 1200 mWh

 

[rider]

if the light is built around 2CR2032, there is a chance to have an Onboard Current LDO with minimum of loss. the light can remain regulated and will have runtime as much as an Arc AAA (if not less) at the same time it would be bright. the energy packed in 2 CR2032 cells is more than 1 AAA by a good margin. To be specific 250 mAh @ 6V (2xCR2032) = 1500 mWh compared with 1000 mAh @ 1.2 V for NiMH = 1200 mWh

Viren, a Reasonable Estimate, using Duracell batteries for instance, would be 240mAh @ 6V for CR2032 = 1440 mAh. 1150 mAh @ 1.5V for Alkaline-MnO2 = 1725 mAh TOTAL capacity. That's not getting into drain characteristics, obviously.

Not only that, your scenario is hypothetical, as the Freedom would probably pop the diode @ 6V, and LRI's lights aren't regulated. Oh, and 2xCR2032 would cost about 20 times what a AAA battery costs.

 

[Sub_Umbra]

...Oh, and 2xCR2032 would cost about 20 times what a AAA battery costs.

How much are you paying for AAAs? Batteryspace.com has CR2032 cells for 35¢ each. (I bought enough for 3.7 lifetimes ) I've read posts that list prices as low as 24¢.

 

[ViReN]

Viren, a Reasonable Estimate, using Duracell batteries for instance, would be 240mAh @ 6V for CR2032 = 1440 mAh. 1150 mAh @ 1.5V for Alkaline-MnO2 = 1725 mAh TOTAL capacity. That's not getting into drain characteristics, obviously.

Not only that, your scenario is hypothetical, as the Freedom would probably pop the diode @ 6V, and LRI's lights aren't regulated. Oh, and 2xCR2032 would cost about 20 times what a AAA battery costs.

not quite literally. because, you have to consider preformance under LOAD. also alkaline has to BOOST the voltage, boosting itself will consume some energy. the current draw to drive LED at 40 mA would be of the order of a couple of 100's mA and alkalines are well known for the non performance in the high current drain situations..not to forget the high internal resistance....


where as the advantage of 2xCR2032 is, we already have a higher voltate at our disposal. relatively much lower internal resistance.

if done properly, I can assure you that the runtime of the 2XCR2032 setup can be longer than ARC AAA .. especially when LED is driven at around 40 mA... ...

CR2032 cells are much cheaper as compared to CR2016

 

[ViReN]

How much are you paying for AAAs? Batteryspace.com has CR2032 cells for 35¢ each. (I bought enough for 3.7 lifetimes ) I've read posts that list prices as low as 24¢.

same here... I am simply looking for a good host to have these cells to run down

in fact, I have been looking for a Turtle light at mec.ca.. but the shipping is much higher..

 

[chimo]

if done properly, I can assure you that the runtime of the 2XCR2032 setup can be longer than ARC AAA .. especially when LED is driven at around 40 mA... ...

Viren, with a 2xCR2032 LDO setup at 40mA, the 240 mAh should get at least 6 hours in regulation. The current draw is around 0.17C so it should get close to the mAh rating.

Efficiency should be around 63% to start ((assuming 3.8Vf LED @40mA) 152mW to the LED and 88mW loss in the LDO) but it will get better as the battery voltage drops and should approach 100% when the LDO can't maintain regulation and the circuit goes into direct drive.

It looks like it would be very simple to implement.

 

[ViReN]

to make things better, it is possible to have a low current synchronous buck regulator or some thing like a low current 'reverse' charge pump with effiencies as high as 95% Sipex has good chips for this purpose but that would make atleast a couple of parts more and so would be the price.

the Vf of Nichia CS at 60 mA is around 3.6 (if i remember correctly, from the jtr1962 thread) so at 40 mA it should be little lesser.

relatively higher internal resistance of coin cells (as compared with larger lithiums) should also make things little easier. (last time i checked) The 2xCR2032 cells should drop to about 5.2 - 4.8 volts from a noload voltage of 6.2 volts.

 

[ViReN]

OK, Here is the Brutal Fact now.... it's a DD with 2xCR2032... the test is still running...

devide by 10 if you want to get lumen numbers.


100% mark = 0:00 Hours = 11 Lumens (60mA)
50% mark = 1:00 Hours = 5.5 Lumens (25mA)
25% mark = 4:30 Hours = 2.8 Lumens (11mA)

Lumens are calculated based on jtr1962 Test...

 

[Sub_Umbra]

Very good. Thank you.

I'm realizing how very challenging it may be trying to correlate hard data to my own experience. I think this test will tell me a great deal.

I'm a dim light guy and my own kludgy test showed that a PF in NV Green with a cr2032 would still provide useable light for me -- for my intended uses days into the test.

This is very interesting. Thanks again.

 

[mpk]

Is the fade in the original graph showing the batteries running down, or the LED being harmed by the voltage/current?

 

[revolvergeek]

I'm a dim light guy and my own kludgy test showed that a PF in NV Green with a cr2032 would still provide useable light for me -- for my intended uses days into the test.

Same here. I have a NV green Photon II with one 2032 on my keyring. Plenty bright for not bumping into things and I am beginning to think that I will actually wear the light out before I have to change the battery.

 

[ViReN]

Update: You could be amazed by this....
Upto 7 Hours

There after readings taken every 12 hours... up to 5 days

after 5 days I got bored ... it's still running...

here are a couple of setup pictures taken just now... LED is STILL ON !