1AA host red with Rkcstr's micro driver

[IgorT]

I've been without a red of my own for a while now, since i gave all my diodes away... But i got 5 of SenKat's new windowless Sony diodes, and wanted to try them out. I also needed a red VERY quickly for some testing.

Since i like my lasers small, i wanted to use a tiny 1xAA host, which would normaly require an AMC or a buck/boost driver. I don't like AMCs, and i don't have a buck/boost driver small enough. I could make one, that fits an AixiZ module, but these small hosts don't have room for an entire AixiZ module.

But i had some parts, which i bought a while ago, and wanted to use them somehow.. So i decided to do it with a rkcstr driver, just for fun.


Too bad it can't work from a single Li-Ion, but... Well, here is the result..


And some testing:
- 203mW after a clear acrylic lens
- 220mW of red at 345mA, after an AR coated acrylic Dilda lens - 8.4% more
- 235mW after a multilayer AR coated custom glass lens - 15.7% more

 

[IgorT]

Re: 1AA host with Rkcstr's micro driver

And these are the special components that make it work...


These are 1/2AA size Li-Ions, which i bought a while ago from AW on CPF, and really wanted to use them for something..
Now they are finally not useless anymore..

 

[IgorT]

Re: 1AA host with Rkcstr's micro driver

The parts... The module is still in the head.

 

[IgorT]

Re: 1AA host with Rkcstr's micro driver

The tiny module, taken from the head...

This is the heart of the laser, everything important is inside and the threads allow it to screw directly into the head of the host, which also helps with heat transfer..

The module is shorter, than an AixiZ module, so there's hardly any room inside. It's only 24mm long and 17mm dia, and the room for a driver inside is 11.5mm long and 9.5mm wide... Very tight!

 

[IgorT]

Re: 1AA host with Rkcstr's micro driver

The module simply unscrews, and gives access to the diode and the driver...


I had an old version of a rkcstr driver.. But of course i knew it wouldn't fit.
So i had to make it shorter..

I managed to reduce it to only 11mm! I moved the output cap behind the diode, and cut the top off to the middle of the output cap pads.
It was still too long, so i had to cut some off from bellow.. I removed the part with the input cap, and moved the input cap to the battery contact board.

Then the two wires connect a little further up, one on each side of the driver.

The diode is then soldered to the output cap pads... I had to bend the legs a little to achieve this, but it worked out nicelly!


I had to make a red without losing too much time, so i could test the some lenses with it, and this was the quickest and easiest solution, as i had most everything else ready...

It also proves, it is possible to make a really tiny laser with Rckstr's driver..

 

[brtaman]

Re: 1AA host with Rkcstr's micro driver

Nice and sleek as usual [smiley=thumbsup.gif]

But 250 mah Thats gonna provide some pretty short run times with a linear driver


brtman

 

[rangedunits]

Re: 1AA host with Rkcstr's micro driver

Nice beamshot!

 

[IgorT]

Re: 1AA host with Rkcstr's micro driver

Nice and sleek as usual  [smiley=thumbsup.gif]

But 250 mah Thats gonna provide some pretty short run times with a linear driver

Well, i have never used a laser for an hour at once, so 3/4 of an hour is more than enough for me. It actually lasts for days. And i always have two sets of batteries for a laser, so that i can charge one and use the other.


I didn't have time to finish a buck/boost driver, that is small enough, but i needed a red now, for some important experiments.
I could have made it with an AMC and get 2x the run time, but i really wanted to put these batteries to use. (unlike DX, these batteries are also not overspecd)
Besides, after making three AMC based reds, i started hating that regulator!   Only one in ten works with an output cap on the LD! And you don't want to be without a cap there!


Since i have better hosts now, i will leave this one as it is.. For a 300mW red, i will use a buck/boost driver and one of the prettier more massive hosts, with a better heatsink/module, like the one i use for blu rays.




Oh, and this one is doing 220mW, at 345mA, but that's partially because i used the AR coated acrylic Dilda lens.

 

[styropyro]

Very nice build Igor! What really amazes me is how much you shortened the rkcstr driver without destroying it ;D

 

[IgorT]

Very nice build Igor! What really amazes me is how much you shortened the rkcstr driver without destroying it ;D

Thanks!


Hehe, yeah, i looked at it, and noticed, that the output cap could easily be moved behind the polarity diode, and that bellow, it could be shortened by relocating the input cap..

The only reason the input wires have to go through the board is the input cap. After i put it on the contact board, i simply connected the input wires a little higher, one on each side.
So i cut a little away at the top and at the bottom, with a diamond plated dremel. I had to cut through the metal at the top of the regulator IC. So instead, i attached some metal on top of it.

Basically, i decided i'll make it fit no matter what. But it was easier than imagined..



This was an old idea, from before i had a tiny working boost driver, so i bought weird battery sizes instead.. I even have 1/2AAA and 2/3AAA batteries!  ;D
And since i had them already, i thought it would be a shame not to use them.. What's better, than using strange bizzare batteries?

For a blu ray pen laser, Rkcstr's driver could easily be used with 2/3AAA batteries - just put three of them in the battery compartment..
Of course battery capacity goes down with this, but personally, i don't have a problem with 45-60 minutes run time with rechargables...

But of course, now that i have a tiny boost driver, i won't actually get to use the even smaller batteries..

 

[gregorio87]

Good work, very nice laser and very nice beam!

How are called those batteries?

 

[IgorT]

1/2AA are called 14250. This means 14mm dia, 25mm long and round (0). They are also called 1/2AA..
AA sized Li-Ions are called 14500 on the other hand.. Again 14mm dia, 50mm long and round.

AAA size are called 10440, 1/2AAA are 10220 and 2/3AAA are 10280.


All of them are 3.6V Li-Ions, that have 4.2V when full and 3V when empty. But due to their size, they are not protected, so one should take care not to underdischarge them.


You can get them from AW on CPF. His batteries are supposedly of a better quality than various DX brands, and their capacity is not exaggerated by 50%. If these were made by UltraFire and sold on DX, it would say 400mAh on them most likelly..

 

[scopeguy20]

Very cool small design! I like it! Great job of engineering from some on hand items. I would bet if you designed one with no limitation on parts you could get, it would be monster power and yet small enough to be a take anywhere unit too!

 

[IgorT]

Hehe, thanks..

It's really nothing serious tho. It's the standard approach with a linear driver, only with everything a bit smaller.
This also results in a shorter run time of course.

But at least i finally got to use the ridiculously small batteries... ;D

 

[BluRay]

Is there a link to this AW or CPF IgorT?
I only managed to find them on DX, and the 10440 is listed at 3.6v @ 500ma but on the batteries it say 600ma. would that make any difference?




tommy

 

[Spyderz20x6]

Is there a link to this AW or CPF IgorT?
I only managed to find them on DX, and the 10440 is listed at 3.6v @ 500ma but on the batteries it say 600ma. would that make any difference?




tommy

That just means it will last longer...