OSRAM 10mw PLT5 510 515nm Green Laser Diode

[kp4djt]

Folks,
I have seen a lot of comments about the higher power Osram 510-520 nm diodes, but I am having an issue finding a driver for the 10 mw diodes. I got a driver from DTR but no joy, a little bit too much power for this unit.

At the moment I have on a larger power supply the following

CC power supply V=6vdc under load it drops to about 5.80 vdc
Current through diode = 74ma.
Light Power = 4mw
NOTE this is a + case, kind of a bummer but I can work around it, but
would prefer a + ground driver for this one. Sure wish there was this diode
but - ground case.

This is about where I need to run the diode less and it drops out of SE and turns into a
nice green LED.

I recall seeing a vendor who sold drivers for this diode but no longer find them.

 

[Mattronium]

I don't think there are any continuous positive boost drivers. The Micro Flexdrive might work with a diode on the input, although it might be a little too high of a Vf for the driver.
The max output was 6.26V for my test.
The Micro BoostDrive looks like it would work better with the higher Vf but innolasers hasn't had them in stock for a while now.

Have you looked at Astral's drivers?

I'd assume that this is for a handheld build.

 

[kp4djt]

I have been looking all over the place for a driver for this diode. I am building it into a
tool, I have the space, it does not need to be real small, as indeed I could even put
the driver in the wall wort, but I am trying to put the drivers in the tool as we plan to
use other wave lengths for different blade finishes. The tools is an alignment tool,
the laser is used to align a head with a cutting knife, some blade finishes look better
under green and some better under red. Ideally will be able to use different drivers
with the same input voltage so I can use a single type of wall wart.

Sooner or later we will probably end up with a blue diode in the mix too, but right
now the target audience is either green or red.

 

[Benm]

I suppose you could just build one?

Given the low power of this laser diode i guess it would be feasible to mount it in such a way that it is electrically isolated from the rest of the appliance (e.g. in an aixiz module that is in a plastic tool) to there would be no issue with case polarity.

Just a very standard driver that puts out the required 74 mA or whatever is a pretty simple build, especially if you have plenty of space.

 

[paul1598419]

The only continuous positive driver that will work with this diode, that I am aware of, is the Blitz Linear driver from Survival Lasers. You will need to supply it with 8 volts or two Li-ion batteries. It is tiny and a PITA to work with, but you needn't worry about isolating the diode from the host.

If you aren't going to need isolation, the new boost drivers from astralist's thread will work fine. You should be able to get down to threshold current with any of these drivers, so take your pick.

 

[kp4djt]

Good info, I will continue to be all ears, thank you very much for all so far. Indeed
one of the options is to just build the driver into a wall wart and be done with it but
then that means we will need a wall wart for each laser type (or a switch to set it
up for the laser in use) . I am looking at the Survival Laser driver right now looks
like the solution. Looks like I may be able to use it for both red and green diodes
(parts count is KING) which also should mean that we can use a single wall wart
to power these guys.

I have plenty of space (about 18mm diameter and 10mm deep) to put the driver
so there should be no issue there.

Since the Osram is positive case, I will probably go with the Blitz linear as that

should take care of the polarity, I am running all positive ground, and since a lot
of the red diodes are also positive ground that should take care of that. Now to
find a low power 450 nm diode that does not cost an arm and a leg.
This thing lines up a sample head for a knife the cut thickness if generally about
4 micrometers. But I have some that do cuts at 500 or 600nm (yes they are
green or orange yellow due to the thickness of the cut) that is the reason for the
laser to make sure the knife is aligned.

 

[paul1598419]

Most visible red diodes are not case positive. Many of the 808nm diodes are, but they are IR and there are some very cheap drivers for those as they have a very low Vf. No need to use a boost driver for them. In fact, you shouldn't even try to use a boost driver for a diode that has a lower Vf than the battery voltage. There are no boost drivers that are for case positive diodes anyway.

 

[kp4djt]

I just ordered the Blitz Linear from SL, I went to their web page made the order and got this rather terse message telling me that they could not complete the order due to being the international page, some mumbojumbo about the FDA. So I closed that up and started looking for the page that was for USA. Found it at the bottom of the page. Their web folks should have put a re-direct in the original "can't buy it here" page.

Got them ordered.

As to positive and negative cases. I have to insulate the driver anyhow. So I will isolate the whole power train and that way use a single wall wart to power the whole thing.

I do hope that at some point someone produces a low power 515-520nm laser (5-10mw) that is case negative. The larger ones are case negative. But they are too large for this application, I tried to run one at the power level I am aiming for but no joy. The 10 mw laser does not want to run much below 5mw.

Again thank you all for all the good info.

 

[kp4djt]

I have ordered the Blitz Linear driver from Survival Lasers, the International page tossed
me a rock, but figured it out and got things ordered.

I am interested in probably a buck driver in this case as I plan to power these from a
wall wart 8-10 vdc output. We are aiming for a single power supply so if a customer
ends up with both red and green devices they will not need to worry about which wall
wart goes to what. I guess it has been a while since I did much with red lasers seems
that they were mostly case positive. But on second look I see that is no longer true.

I plan on insulating the laser module from the rest of the tool so if I have a case
positive diode it should not matter.