Another project red?

[buffo]

Lasorb will protect against ESD, not agains crappy drivers, any overvoltage to a driver can still kill your diodes.

So what you are saying is, use a quality driver that will not over-volt the diode... And I completely agree with this. But that has nothing to do with how *many* drivers you use.

My original point was (and still is) that there is no added reliability inherent in a design that uses multiple drivers verses a design that uses just one driver. So long as the driver is suitably protected against over-voltage on both the power input *and* modulation input, you gain nothing but added cost and complexity by using more of them.

The added reliability comes from the lasorbs on each diode to protect against static. And with them installed, so long as you run the diodes within their current limits and avoid back-reflection, you should have zero reliability issues.

Andy does have a point in that the driver you select must be able to handle the current draw of all your diodes without overheating or failing, but there are several affordable drivers on the market today that can provide several amps of constant-current drive, so unless you're building a 30 diode monster, this really isn't an issue.

Adam

[mccarrot]

Reliability? That's what the lasorbs are there for. Having extra drivers doesn't buy you anything in terms of reliability. If anything, they add more components that could fail. (Though I agree that I've never seen a driver fail, so it's not a likely occurrence in any event.)


Adam

Ok, I think I misunderstood what you where trying to say.

I thought you said a Lasorb will protect your diodes even with cheaper drivers. Good drivers will only add more compenents to fail, but you where taking about more drivers.

My oppinioun: To have a reliable system you need qualty drivers to start with, Lasorb is only extra protection against esd where even good drivers have problems filtering them.

[MisterWilling]

I don't know what his plan is for this rig, but on a previous unit he wired the diodes in parallel with a small (1 ohm) current-balancing resistor in series with each diode. Also, on that laser each diode had a lasorb attached. I imagine the final product here will be similar.
Adam

I am going to build my rig using two flexmods each powering 4 diodes each. Still havn't decided which lens to use but something better then the aixiz acrylic; but not as expensive as the $25 dollar 1% loss glass lenses I buy now. Since I can machine all the mirror mounts and mounting hardware my total cost for 2W of red (minus the telescope and knife edge losses) would be $70 for drivers, $80 for diodes, $50 for lasorbs, plus whatever lenses costs and the telescope. Not a bad deal.

[logsquared]

That certainly looks like a very nice driver to have. But one of the goals was to be able to make this laser without spending as much as buying a new unit. Mine is almost finished ,with exception of aligning, and have yet to burst the $250 mark. This was in the original post. This was intended to help others to be able to create a good laser at a very attractive price- given they can do a little machining and cobble a few parts. Just trying to get others involved building things.

Exactly my thought as well.

With regard to drivers and reliability. In my opinion putting the diodes is series is the best method if you can isolate them(my 6x BR are already isolated making series really easy). Wiring in series will allow the driver to dissipate the same power regardless of the number of diodes. This assumes the power supply voltage is adjusted for the number of diodes used. If a power supply failure or transient gets past one driver chances are it will do the same to all the drivers on the same supply. So, for increased reliability with multiple drivers you really need to have a separate power supply for each driver. Plus, with a DPSS there is usually only one diode and one driver. How many projectors are using multiple DPSS lasers just for reliability?

All that being said... I would still feel comfortable with 8-10 diodes is parallel if not run to the limit. If you have 10 diodes running at 320mA and one dies open all the other will get 356mA. Not a huge increase. Especially if you check your set-up before each show.

[andy_con]

Exactly my thought as well.

With regard to drivers and reliability. In my opinion putting the diodes is series is the best method if you can isolate them(my 6x BR are already isolated making series really easy). Wiring in series will allow the driver to dissipate the same power regardless of the number of diodes. This assumes the power supply voltage is adjusted for the number of diodes used. If a power supply failure or transient gets past one driver chances are it will do the same to all the drivers on the same supply. So, for increased reliability with multiple drivers you really need to have a separate power supply for each driver. Plus, with a DPSS there is usually only one diode and one driver. How many projectors are using multiple DPSS lasers just for reliability?

All that being said... I would still feel comfortable with 8-10 diodes is parallel if not run to the limit. If you have 10 diodes running at 320mA and one dies open all the other will get 356mA. Not a huge increase. Especially if you check your set-up before each show.

im using multiple drivers and psu for my setup

[FourDee]

I believe this driver is cheaper than the Kvant driver. It has 6 output channels and a simple TEC driver

19112009222..jpg

[andy_con]

I believe this driver is cheaper than the Kvant driver. It has 6 output channels and a simple TEC driver

Attachment 14737

spec and cos t?

[logsquared]

I believe this driver is cheaper than the Kvant driver. It has 6 output channels and a simple TEC driver

Attachment 14737

More info please!

[mccarrot]

arround 150 euro, but not available yet.

[edison]

any idea when it is ready?

[mccarrot]

I have checked this with the manufacterer, so please be patient...

But a 6 ch driver starts me thinking of a Hex moduleinstead of quad

Without the use of a telescope I think a beam of 3,8mm x 3,8mm x 0,8mrad should be possible with a hex module.

3,5mm or even 4mm beam is still very acceptable I think.

PS. on my webshop you can also find waveplates. with these optics you can turn the polarisation of beam, so no need for stacking the beams vertical anymore.

[FourDee]

I think those drivers will be available shortly from the manufacturer (http://www.laserparts.ch) at around 125€

Also, this guy makes a mini driver for dpss lasers, with 2 bipolar tec drivers and a diode driver in a very small package.
He also has some other nifty things on his todo list, so look out for this

[logsquared]

Mine is almost finished ,with exception of aligning, and have yet to burst the $250 mark. This was in the original post. This was intended to help others to be able to create a good laser at a very attractive price- given they can do a little machining and cobble a few parts. Just trying to get others involved building things.

Any pics yet? Looking forward to see how your combiner comes together.

[andy_con]

if your wondering why i wanted all those mirror mounts well here a tease

[Doc]

^^^^ Yeehaaaaaaaaaah! ^^^^

Looking forward to watching this one develop Andy, I hope it works out well.

[hobbybob]

Nice Andy !
Do i see correctly that every row of 4 is a bit lower than the one to the left of it ?
So to be able to stack the beams ?

[andy_con]

Nice Andy !
Do i see correctly that every row of 4 is a bit lower than the one to the left of it ?
So to be able to stack the beams ?

correct .

[andy_con]

last photo of this build

[hobbybob]

Nice andy !
How thick is the ally corners holding the mirrors ?
I bought some Ally angle measuring 30x30x3mm Would that be thick enough to make some mounts ?
And how thick is the small square block holding the mirror ?

Have mounted 4 diodes in the blocks you made for me. First i wanted to use some mounts made by Phil phritzler, but those are way to high to place the mirrors. In the blocks you made for me the diode center is around 11mm high. So i need to make some lower mounts, or raise the blocks with around 18mm to get to a beamheight center of around 29mm... Maybe i will go to the scrapyard tomorrow to find some small blocks/plates ally.... and continue the lowcost quad.

Your pictures surely are an inspiration.

[andy_con]

the angle is 3mm thick and the front bit that holds the mirror is 4mm.

[hobbybob]

Thanks Andy !
Bought some 5mm angle yesterday (as i thought it was 5mm thick), but that doesn't matter i guess.
Also bought some grubs, but will buy more from Ebay. The local retailer asked 60 eurocents EACH...
On ebay it's like 50 for 2 or 3 dollars.... ;-)

Furthermore i found some nice aluminium tubes of 48mm for my CNC project. But i won't pollute this topic with that.

[MisterWilling]

Now that blue has become so cheap, maybe we should resurrect this thread because I know some people may have to upgrade their red to match the now dirt cheap 445!