1st 445nm build... ideas?

Howdy folks... I've been here on LPF for awhile, reading here and there... I'm pretty excited about the 445nm diodes (I have had to put away lasers for awhile, after having a midlife crisis).

Anyway, I'm not a complete newbie to lasers either, I've built a 405 (started out as a PHR in Dec. of 08, then I moved up to a LG 10x in June of '10) out of some spare greenie parts and iron pipe&fittings from hope depot... not a very clean build, but hey... function over form was the way I was going for at the time.

I'm planning to get a lathe so I can do my own heatsinks, hosts even, and I do have a decent array of tools available to me (or at least I can make it so given time), but I've got some ideas here that I'd like some feedback on.

I'm not excited about running out of juice, so I'm thinking of doing a sort of 'tri battery setup' with 18650's in parrallel using a boost driver. I'm not looking to go too much over 1.2W, so I should't need tandem drivers either. I do realize that the size constraints of the batteries would mean a host diameter of around 40mm... plenty of space for a good size copper heatsink, I'm thinking... and as for the host, I'm thinking of milling some aluminum and anodizing... we'll see. I'm not really into using flashlights, but I'd consider it if it does the job.

any ideas? Thanks for y'all's input!

Rick

When someone asks this kind of question, I always spam this link.
So you want ideas of something other than that or a flashlight?
Off the top of my head, how about some steampunk-styled laser?
Decently sized brass tube and your off....

I was actually thinking about a 'labby' style, running off a PC's PSU (AC as the source)... I like portability though.. Another thing I was thinking about is instead of using the potentiometer on the driver, I was thinking of using a 3 way switch to achieve multiple power modes, and if this can be done with tandem drivers (yes i know i said earlier that I wouldn't need it- I'm just exploring ideas) then it would be cool to do a Lo power setting (50-75mW), a 'normal' setting (1W) and a Hi setting at like 1.5-1.7W that can be used temporarily. Would adjusting the power output of the laser in such a manner with it on kill the diode? I wouldn't think so if it is cap-protected... I just want to make sure ignorance doesn't kill a $40+ diode, or the woman is going to be mad. :O

Most newbies have killed at least one diode (myself included), tell the missus that they are worth $80 and when you come in under budget everyone is happy! lol jk
There are no problems powering the diode like you are talking about but why not just wire it up so that you use different combinations of resistors for the same driver?
Just a side note, these diodes' lasing threshold is ~200-250mW, below that they are just a REALLY dim led ^_^

*edit: Don't know if you have run the numbers on 18650 battery life yet but I use my 445 quite a bit @1.6W and I have yet to charge my (one) battery.
I have better efficiency with the flexdrive but still, these batts have a HUGE capacity.

anubis said:

I was thinking of using a 3 way switch to achieve multiple power modes, and if this can be done with tandem drivers (yes i know i said earlier that I wouldn't need it- I'm just exploring ideas) then it would be cool to do a Lo power setting (50-75mW), a 'normal' setting (1W) and a Hi setting at like 1.5-1.7W that can be used temporarily.

Click to expand...

I have thought about and implemented such an idea as yours:
http://laserpointerforums.com/f67/hi-lo-mode-lm317-driver-proposal-58231.html
Works just fine.

autoxx said:

*edit: Don't know if you have run the numbers on 18650 battery life yet but I use my 445 quite a bit @1.6W and I have yet to charge my (one) battery.
I have better efficiency with the flexdrive but still, these batts have a HUGE capacity.

Click to expand...

That must a be magical battery, because mine don't last more than 2~3 hours at most,
driving a blue nichia at >1W !!

I've got most of the dimensions figured out at this point... I'm currently stuck on a rock and a hard place on drivers though. what's the best one out there to run a 445 nm on? I'm thinking either a flexdrive v5 or a micro boost... calling out to those with some experience here

I prefer the Flex, more power turned all the way up.
The fact that it is a buck driver as well as boost gives you more options for battery/host options as well.
The microboost is better for a 405 because it will supply sufficient voltage.

I'm currently designing the host I'm building and I've hit a snag.. does anyone know the thickness of a Flexdrive? I know its 9mmx12mm... but how thick?

4mm-4.5mm to the top of the inductor to the far side of the highest component on the opposite side.
I can get a set of calipers if you need a more accurate measurement

ok, I've hit a roadblock in the electrical design. for the Low power mode I'd like to put out around 400mA, however this involves adjusting the 'range' of the flexdrive (see attachment). does anyone know what the amount of current is that flows between the areas connected by the solder 'blob' that controls the range?