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

IgorT

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

Yeah, i understand what you mean, but i still think my tailcap (it's outside part) is shorter. Most of the tailcaps length is inside the barrel.
And even if i measure from the outside from bottom to button, i only get 26mm, not 28mm. And it's impossible to drill all that out, i'm afraid, since it gets narrower and narrower....

Otherwise, my tailcap did have a spring. It was in that hole you can see in the picture, i took it out since it won't be needed.


I don't know... It's like 1-2mm missing. Maybe it's possible, not sure.. I'll ask you to drill the tailcap as far as you can, without coming through on the other side anyway.... After that, who knows....


The button is a bit too low on the barrel (too close to the tailcap). Maybe if i created some kind of a lever, that would press an inner button (mounted higher up in the barrel), when you press on the outside rubber piece.

I would have to rearrange the insides, make my own contact and button assembly, with a lever, then it might just work with an 10280. But this would be a VERY complicated modification!


A thing that i could do would be a self adhesive "foil button", glued on the outside, wired in  through the button hole. It's flat cable would not obstruct the battery. Then i would have room all the way to my driver. But i don't know if they can be applied onto curved surfaces.


It is possible theoretically. It just won't be easy. But then, why did i just buy a shitload of tiny batteries? You're gonna make me regret ordering all those 10220's (i hope)... ;D



EDIT: I got it! The "lever" could engage the positive battery contact, and connect it to my driver! :D
But how to make this lever? Where to mount it? Maybe i should create a "pivoting solder hinge"? ::)
 





jayrob

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

Got your wheels turning now! ;D

I'll drill them out as deep as I safely can. And hopefully you won't need to modify the switch...

It's going to be close! I can see that your threads are longer than 5mm's. Plus, the spring probably stuck out maybe 1 or 2mm's when making contact. There just may be another 3 or 4mm's to be gained beyond the threads!

Here's a couple of more pictures for your reference...

key13.jpg

key14.jpg

Jay
 

jayrob

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

For a build like this, where your module goes in last with a 'light' press fit, a custom tool is needed to be able to remove the module for diode replacement if ever needed...

Custom AixiZ Tool.jpg


The plastic AixiZ nut is not strong enough to to pull out the module. And if you unscrew the head, the wires will twist and destroy the driver connections in this very tight build.

I made this custom tool from solid brass round stock (in case I ever need it), which will work well for Leadlights, and this tiny Key Chain build as well! ;) It is 4" long, for a nice grip.

The thread size is 9 X 0.5

Here's the site where I bought the tap and die set: (look for 9mm X .5) Thanks for that Kenom! :)
Tap - http://www.victornet.com/cgi-bin/victor/productlist.html?subdepartments=Metric+Taps:602,902,604
Die - http://www.victornet.com/cgi-bin/vi...tments=Dies,+Metric+(up+to+10+MM):603,606,599


Use a 7/32 bit for the hole in the tip of the tool... That way you can screw it all the way into the module, and not worry about the tool hitting the diode...

These threads are so fine, that there is pretty much no tolerance. Your piece must be exact before threading. Use a caliper that is accurate to 1/1000th. Then, get your material diameter exactly .361 in., and your good to go for the threading! :)


It's a good idea to leave an AixiZ module threaded on for protection when storing the tool...



I'll make one for you if you want one Igor... As an extra thanks for giving me your pocket clip blu-ray just for the little bit of work I did on the modules. :)
Jay
 
Joined
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Re: Key Chain Blu-ray... With FlexDrive!

hey Jay what tap size is that  :D

just wanted to know so i could make myself one :p :p
 

IgorT

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

You know, that might come in handy.. :) Thanks Jay!


Otherwise, yeah, you got my wheels turning now. I can't stop thinking of ways how to get the 10280 in there... ;)
 

jayrob

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

Ok Igor, I'll have one of these custom tools ready for you to send back with the other stuff...





john_lawson said:
hey Jay what tap size is that  :D

just wanted to know so i could make myself one  :p :p

It's an odd size alright...

Kenom told me what it was. Thanks Ken! :)

The thread size is 9 X 0.5

Here's the site where I bought the tap and die set: (look for 9mm X .5)
Tap - http://www.victornet.com/cgi-bin/victor/productlist.html?subdepartments=Metric+Taps:602,902,604
Die - http://www.victornet.com/cgi-bin/vi...tments=Dies,+Metric+(up+to+10+MM):603,606,599


Use a 7/32 bit for hole in the tip of the tool... That way you can screw it all the way into the module, and not worry about the tool hitting the diode...

These threads are so fine, that there is pretty much no tolerance. Your piece must be exact before threading. Use a caliper that is accurate to 1/1000th. Then, get your material diameter exactly .361 in., and your good to go for the threading! :)


It's a good idea to leave an AixiZ module threaded on for protection when storing the tool...
Jay
 

jayrob

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

Yes, you are right. That was my saved link to the site. It went to the taps...

I went ahead and fixed it above so as not to cause any confusion.
Jay
 

Kage

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

IgorT said:
...
P.S. Now that i think of it, a near 300mW current draw is a lot for such a tiny battery! That's 3.3C! I don't know what their rated discharge capability is - probably 2C, but it sounds a little high. The higher the efficiency of the diode, the better for the tiny Li-Ion! (That doesn't mean i won't do it of course.. ;D)

Alright Igor, we can all understand torturing diodes, but Batteries? Dear lord, where will it all end?! ;D
(I was back a few pages)

Would anyone be interested in my doing a Constant Current Discharge curve of a 10440 or other Dia. Lithium cell?

I was thinking doing it at a higher rate like 800mA which would be 800/320=2.5C. That info could be used to accurately predict run time for other lengths/capacities of the 10mm batteries because it would plot the output voltage under load - over time.
 

jayrob

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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
 

IgorT

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

Kage said:
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? ;)



Jay: I forgot about this, i was preoccupied. I am just preparing for the last day of a certain conference. Well, actually i'm trying to forget about it at this moment.  ::)


What i wanted to do, was take the average voltage of the battery - the voltage it would have when half empty - and calculate Flexy's current drawl at that voltage, to get an "average" current draw... It's a horribly simplified approach, but, there are so many factors interacting here... Better not go into any details. ;D


Problem is, i don't know the forward voltage of your two diodes. I can only guess, or use mine for the example..


You said PHR at 117mA.
I don't have my diode notebook with me. And if i did, it wouldn't match your diode anyway.
So let's say your PHR needs 5.2V for 117mA to flow through it.

- The FlexDrive needs to put out 5.2V x 0.117A = 0.6084W <-- power going into the diode.
- Since it operates at some 90% efficiency, that means 0.6084W is 90% of the power going into the FlexDrive, from the battery.
- 0.6084W x 10/9 = 0.676W  <--- That means the Flexy is sucking 0.676W from the battery all the time, regardless of the battery voltage. It pulls "constant" power.. (For the power to stay the same, the current has to climb as the battery voltage drops.)


Ok, a full Li-Ion has 4.2V, but under load it's 3.9-4V (at least with big ones here it would be less, a low capacity battery will sag more).
We are willing to discharge it down to 2.7V. So let's say from 3.7V down to 2.7V. That's 1V to go. The "average" is then 3.2V...

So now i need to calculate the current draw at 3.2V..

- The Flex is sucking 0.676W at 3.2V, P = U x I => I = P / U = 0.676W / 3.2V = 0.21125A = 211.25mA   <-- That is the current the Flex has to pull at 3.2V, in order to put out 117mA at 5.2V with 90% efficiency.
Ok, so now, if the discharge was linear, this could be taken as actual average current, and you could calculate the battery life from it.
- 180mAh / 211mA = 0.853h x 60 = 51.18 minutes.. Sounds a little much..


At this point more problems appear. The capacity of the battery is probably not 180mAh. And it changes with the current draw. The current draw is changing with the battery voltage, voltage drops from discharging (current gets higher and higher), and the discharge is not really all that linear....

But still, for a PHR at 117mA from an 180mAh Li-Ion, it doesn't seem to be too bad. I expected worse.



Now for the red at 180mA:
- Flex puts out 0.18A x 2.7V = 0.486W (you are going too easy on the red, Jay, the PHR at 117mA is a heavier load than a 180mA red!).
- Due to 90% efficiency, Flexy has to pull 0.486W x 10/9 = 0.54W...

- If i take the same "average" voltage of 3.2V, then I = 0.54W / 3.2V = 0.16875A = 168.75mA.
- So for the Flex to put out 180mA at 2.7V it has to pull 169mA at 3.2V... That would be 64 minutes.. (If the discharge was linear and capacity actually 180mAh).



I had to ignore many different factors here, for this calculation, as well as make up numbers (diode forward voltage), it's nowhere near accurate. It's just to give you a feeling of what is going on..



While i'm at it, let's do the 6x at 180mA.
I'll take mine for the example. It needs 5.15V for 180mA to flow through it.

- Power coming out of FlexDrive = 5.15 x 0.18 = 0.927W
- Power going into the FlexDrive = 0.927 x 10/9 = 1.03W

- Current required for 1.03W at 3.2V = 1.03/3.2 = 0.322A = 322mA <-- Flexy has to pul 322mA at 3.2V to put out 180mA at 5.15V
- "Battery life" = 180 / 322 x 60 = 33.5 minutes

Again not as bad as i feared. But it is an 10280 now.. It was only half as much before... :)



P.S. Even tho i tried to err on the side of "caution", i think the numbers are still too good. In reality it may be 70-80% of what i just calculated....
But the numbers still show it's not impossible to do this. The 10180 would suffer badly, the 10280 is perfect for this on the other hand.... I just hope i can get the 10280 in as well! If i can get 20 minutes or a bit more of 200mW, i'll be VERY happy! ;)

P.P.S. It would definitelly be good if it was possible to incorporate the protection circuit into such a build.
 

jayrob

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

Igor, thank you for doing these calculations! :) I love to read your informative posts...

You will for sure get a 10280 in the Key chain host that I sent you. And we will try our best on this end to make room in the other ones too.

I am happy with the numbers you came up with! :cool:

About the tiny protection circuits you mentioned... Is it possible for me to get a few? Can I just buy them somewhere?
Jay
 

danq

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

jayrob said:
About the tiny protection circuits you mentioned... Is it possible for me to get a few? Can I just buy them somewhere?
Jay
(butting in here to answer because I'm up late too... )
Yes, you can - not sure about size factor though. And I don't remember where I saw them - one of the battery websites I think - maybe Powerstream?
am I helping? ;-)
 

IgorT

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

Yeah, some battery page sells circuts. But they have two sizes and they are expensive.

The circuit i'm getting is 10x5mm! It comes from built-in BlueTooth or MP3 batteries..



BTW, i wrote you a reply about it last night but my laptop was acting up again, and gmail didn't want to send. I barelly managed to save the draft. Now that you reminded me, i sent it...


There are several possible issues with this circuit. But if i can get it to work we'd have to buy 100 of them.
The only other way to get them would be buying the battery they come on.

The one thing that worries me is current limiting - i hope it doesn't have it.
The other thing is incorporation into a laser - i'm pretty sure it would work with BluRays.. But it might not work with reds..
 




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