268mW 6X Key Chain Blu-ray! (With FlexDrive!) - Awesome!

[IgorT]

Re: Key Chain Blu-ray... With FlexDrive!

When i said that a red and a blu would be the same load, i meant a red and a blu of the same power..

Look: (bottom of page 3)

But if you use the 660nm AR coated acrylics, i see no reason not to get the same battery life with a 200mW red as with a 200mW blu..

In the battery life calculations i said the 117mA PHR was a heavier load than a 180mA red. Ee went through so many different diodes at different currents, that i got confused as well..


Anyway, you have a 200mW red now. If you test the battery life with it, then you can simply assume, that the battery life with a high efficiency 6x will be similar. How similar depends on the 6x's nd red's Vfs (because that determines their actual efficiency). 405nm's have higher losses in optics, but you found a freak 6x. If it's actually a high efficiency diode then the battery life should be similar.

Besides, you can test this simply by measuring the Flexy's current draw on a full 10280 when powering that 6x, and comparing it to the 200mW red. If you get the same or similar starting current draw, the battery life will be similar.


But there are cases, when 405nm diodes just seem to have a higher efficiency (differential efficiency - mW per mA) while in reality they have a higher Vf, and the actual efficiency (mWoptical per mWelectrical) is not really higher.

I've noticed this, when testing 4x diodes. A few of them had seemingly MUCH higher than normal efficiency. But then i looked at the Vf data, and they also had a much higher Vf! But i never went as far as to actually make mWopt. per mWel. comparison graphs.. But it would be interesting to do so


If this should be the case with your freak 6x, then the higher differential efficiency won't make it consume less electrical power..

 

[morphs]

Re: Key Chain Blu-ray... With FlexDrive!

Have you figured a way to make the button stay on?? I am going to see what I can come up with.
Just wish there were some lava drives available..

 

[jayrob]

Re: Key Chain Blu-ray... With FlexDrive!

I only tested it a couple of times to make sure, but it did not work with the FlexDrive. So I just by-passed the component, and allowed it to become a momentary button, like a Leadlight.

But this may be a better set up for this tiny build, considering the fairly low battery capacity. A momentary button will help to limit 'on time'.

And also, it won't get turned on accidentally...
Jay

 

[morphs]

Re: Key Chain Blu-ray... With FlexDrive!

Good points.. Nice Build!!

 

[jayrob]

Re: Key Chain Blu-ray... With FlexDrive!

Battery tip:

I got my 10280's and they say 200mAh on them by the way!

I thought I would show that it is an easy mod to expose the negative end of the battery edges. This is needed with this build using the longer batteries. Because of the tail cap mod, there is no longer a center spring...

Also, I re-tested my battery current draw readings for these two FlexDrive builds using these new batteries:

PHR-803 blu-ray set at 117mA's - 175mA's battery current draw.

1239JL-54 red set at 275mA's - 228mA's battery current draw.
Jay

 

[Kage]

Re: Key Chain Blu-ray... With FlexDrive!

Kage, I would definitely be very interested in this!

We are talking about using 10280 batteries, which are 180mAh capacity... and running these little Key Chain builds using a FlexDrive at up to 180mA's for a blu-ray, and 300mA's for a red diode.

Per Igor, this would be approx. the same draw on the battery using a Flexdrive. At least that's what I understood his calculations for a boost vs buck situation with the FlexDirve depending on the diode used.

* I have a PHR @ 117mA's, and would love to some how calculate the safe run time expected with a 180mAh battery.

* I also have a red at 180mA's, and I sure would like to know if anyone has any way to calculate expected run times with this set up as well!

Maybe an hour or so for each set up huh?

Waiting for your thoughts on this too Igor...
Jay

[quote author=Kage link=1230765788/100#105 date=1232067654]Would anyone be interested in my doing a Constant Current Discharge curve of a 10440 or other Dia. Lithium cell?

Kage, what is needed is a constant power discharge curve, since we're dealing with switching drivers in this case.

Would you do that perhaps?

[/quote]

Sorry, i was missing for a couple of days...

Well I did the Constant current discharge for the 10440 - a brand new one, fully charged to 4.2V. I needed to learn to use a better graphing program, so this is a sort of learning experience - now my graphs will be prettier at least.

Igor, I know what you are getting at. Since the LD is powered by constant current, and the LD voltage remains essentially fixed, current from the battery has to INCREASE over time as the battery voltage drops - because of the boost converter representing a constant power load. My next graph will be at a constant power, then.

I will use an actual boost driver set to a fairly high current so that the battery load crosses the 2C point during discharge. It may be a day or 2 before I can do it, but I will. Any exact parameters you want - such as a specific power to the load - let me know.

The following graph shows that even at a constant current - which is easier on the battery than constant power, you will never get the full capacity out of the battery at these discharge rates!

At the beginning of the test, I measured the internal cell resistance by noting the instantaneous drop in voltage - .3V @ 800mA - or .375 ohms. At the end of the test my tester automatically disconnects the battery at 2.75V as though it had a protection circuit in the battery. After the battery protection cut out, the battery terminal voltage slowly recovered to over 3.75V! So I did another resistance test. This time the voltage dropped by .8V, giving a cell resistance of 1.0 ohm!

The implications for even shorter versions of the 10mm battery are not good... and the constant power discharge will no doubt be even worse. :-/

 

[jayrob]

Re: Key Chain Blu-ray... With FlexDrive!

Kage, thanks for the testing and graph!

Hmmm... looks like it might be better to stick to a high efficiency PHR diode huh? Perhaps it won't be that bad on the batteries, because I won't be just leaving it on for a constant current draw on the battery, but more like 30 seconds at a time...
Jay

 

[jayrob]

Re: Key Chain Blu-ray... With FlexDrive!

Battery Current Draw - for 3 different builds:

Here are my three different builds and the current draw on fully charged (200mAh) 10280 batteries...

* High efficiency PHR-803T blu-ray set at 117mA's and putting out 117mW's. (AixiZ acrylic) - 175mA's battery current draw.

* Sony/Senkat SLD1239JL-54 red set at 275mA's and putting out 200mW's. (AR coated lens) - 228mA's battery current draw.

* High efficiency (freak) 6X blu-ray set at 183mA's and putting out 215mW's! (AixiZ acrylic) - 288mA's battery current draw.

I'm guessing the 6X build will be 30 minutes run time (or less), but who cares?... It is now giving me 268mW's! (405-G-1 glass lens)
Jay

 

[Th0ughts]

Re: Key Chain Blu-ray... With FlexDrive!

217 mW from a PHR? Wow, you really got a freak diode .

 

[jayrob]

Re: Key Chain Blu-ray... With FlexDrive!

That was a typo... I had just fixed it before you posted. PHR - 117mW's...
Jay

 

[IgorT]

Re: Key Chain Blu-ray... With FlexDrive!

Nice, Jay!

And thanks for the current measurements. See, the red and the blu at 200mW have a similar current draw, but the red has an easier job at passing light through the lens (especially with the AR acrylics!), and the blu is at a higher power, so it needs even a bit more electrical power IN, than the red.... Considering all these factors, it's possible that their actual efficiency is nearly identical.

I also need to check if the "higher efficiency diodes" (more mW per mA) in reality only have a higher Vf, which means that at the same current IN more electrical power goes into the diode...


I'm not done compiling all the data yet, but i should really look into comparing the Vf of "higher efficiency" diodes to the "lower efficiency" ones. It's possible that the actual efficiency is not really that different.



Otherwise, i just got a bunch of batteries from AW! I extracted the protection circuit from flat ones and will do some tests. That thing is TINY!

This would EASILY fit into these tiny micro hosts! The only thing i need to test is which current it shuts down at, and then i can make a protected blu ray using an unprotected cell. I'll send you one of the two circuits, Jay, so you can put it into the 6x. That one is gonna need it the most!

With trimmed corners, this circuit could even be attached to the bottom of a 10mm cell, altho it would make it some 3mm longer.


I think it's time i send you all the stuff. By the time it gets there i will have the wiring figured out, altho it should be as described in one of the previous posts...




Kage: Thanks for doing the test! Nice work! Doesn't look good for the batteries tho.

Is your 10440 from AW? Cos DX are rated for 600mAh, which is impossible, but your plot says "capacity 320mAh"...


Looking forward to the constant power discharge curve! I already feel bad for the battery..




EDIT: Jay, how well do those black stickers stick? Do they gradually start peeling off, or do they stay put?

 

[jayrob]

Re: Key Chain Blu-ray... With FlexDrive!

Nice, Jay!

And thanks for the current measurements. See, the red and the blu at 200mW have a similar current draw, but the red has an easier job at passing light through the lens (especially with the AR acrylics!), and the blu is at a higher power, so it needs even a bit more electrical power IN, than the red....[highlight] Considering all these factors, it's possible that their actual efficiency is nearly identical.[/highlight]

I also need to check if the "higher efficiency diodes" (more mW per mA) in reality only have a higher Vf, which means that at the same current IN more electrical power goes into the diode...


EDIT: Jay,[highlight] how well do those black stickers stick?[/highlight] Do they gradually start peeling off, or do they stay put?

One big difference I noticed, was the battery current draw from a low battery between the red and blu-ray at + 200mW's. The current draw does not go up that much on the blu-ray. Maybe because it was already having to boost all along...

About the stickers. Yes! The are excellent. I'll send you a couple to sample in the package...
Jay

 

[danq]

Re: Key Chain Blu-ray... With FlexDrive!

About the stickers. Yes! The are excellent. I'll send you a couple to sample in the package...

that's funny... earlier this morning I was going to send Jay a PM to ask where he gets those stickers - I didn't know they were being discussed already.

So... Jay, are you printing them, or buying them already made?

DanQ

 

[jayrob]

Re: Key Chain Blu-ray... With FlexDrive!

The foil warning labels I got from andy_con...

And he told me that he is not going to make any more, so what I have left of those, I am going to keep.

But Igor was asking about the little stickers that I make for the power measurement and to say what diode is being used. Those are white print on black tape. Very nice labels from a P-Touch printer.

The labels are # TZ-335. My printer is model # PT-1010...
Jay

 

[danq]

Re: Key Chain Blu-ray... With FlexDrive!

Thanks Jay!

DanQ

 

[IgorT]

Re: Key Chain Blu-ray... With FlexDrive!

One big difference I noticed, was the battery current draw from a low battery between the red and blu-ray at + 200mW's. The current draw does not go up that much on the blu-ray. Maybe because it was already having to boost all along...

That shouldn't be like that, Jay... Did you measure both with the same empty battery? Cos even if you measure two batteries as at the same no load voltage, in reality they can be at a much different charge level. No load voltage is not a good indication of the battery charge state.


If you measure both with the same battery you should find a near identical current increase (in percentage of starting current).

The driver in blu does boost all the time, meaning it is slightly more efficient, but this efficiency doesn't change, since it depends on the output voltage. Besides, it's a small difference.


So i'm guessing you simply haven't discharged it as far as the battery in the red yet. Or the full battery current measurement was not correct (maybe the battery wasn't completelly full, or is weaker than the other).

Try it with the same battery and you should see the same increase. Not in mA but in percent. If the blu takes more power, the increase in mA will even be higher