Group buy for 16X dvd burner diodes !

I'm pretty sure that 350ma will be a pretty quick death to these diode's even with good heatsinking.  I think it's just too much current.  I want 300ma MAX. I should email merideth and ask them what the output voltage is on that thing. I'm assuming 3.5V. which again will be a bit high but that can be solved easily with a different resistor. It comes unassembled and wouldn't be that hard to change a resistor.

Could you just use a single resistor like what I have always used for L.E.D.s or will that kill the diode? OR does the driver board do more than just limit current?

The output voltage doesn't really matter much as long as it is above the forward voltage drop of the LD, which is 2.5V. The driver outputs a constant current which is the important thing. They do specify the input voltage which tells you how many batteries you'll want.

-- Rev

the driver board does indeed do more than just limit current. IT makes it STABLE CURRENT. no peaks or spikes.

If the second driver board will work with a few simple modifications I might pop for em and then sell the extra's I've got at a reasonable price. GB if you will.

Remember Roithner? They make driver boards.

http://www.roithner-laser.com/Drivers.htm

The EU-38 driver board I think would be the best option, and according to their price list costs $15.88 USD for an order of 1-49.

I do not believe a driver board is needed. I am running hte 12x version in a Dorcy Jr host bare, and it is pumping out 160mw easy. It even burns light colored oak on my desk !!! So - Once these little suckers come in, it will be a matter of adding a tiny cap and resistor combo to the existing circuit to get it all up and running smoothly ! I hope that made sense. I will post the values of each item as needed.

Daedal said:

[quote author=Kenom link=1183788027/15#29 date=1183840224]Merideth does sell a driver board that will work for this! problem is it's expensive as HELL! $49.00 it will fit into a pen style laser barrel.
http://www.mi-lasers.com/cgi-bin/sh...hstart=0&template=Templates/SearchResult.html

I'm also looking at a driver board for a LED flashlight that might work with a little modification.
http://dealextreme.com/details.dx/sku.3160

Since I am not that electrically knowledgable I'm having to ask other's if the driver boards I've mentioned will be sufficient. I will let everyone know when I find out more.

Click to expand...

The first board doesn't tell you what the output voltage is, the second board I think would be great... Especially the way they have it pictured with nothing on there except for the ramp chip and the diode I was thinking of working on one these... I'll have to do it sometime considering I have a few lying around gutted from other flashlights

--DDL[/quote]

Hello Daedal,
I have learned to think in terms of current when playing with diodes. Voltage doesn't matter to me and I hardly even look to see how much voltage I am applying. I always monitor current when playing around.

What Kenom is saying about driver boards providing stable current to the diode is true. However, one can get by using the proper resistor ( we are on exactly the same page with that one) and a capacitor.

I have been using a driver board on my home made laser and it is still running the same as the day I put it together. The driver I am using isn't adjustable. However with 4 nimh batteries it provides 240ma of current to the diode. I guess my point is by using a driver board, the diode is likely to last much longer, at least this has been my experience.

Gazoo said:

[quote author=Daedal link=1183788027/30#31 date=1183840655][quote author=Kenom link=1183788027/15#29 date=1183840224]Merideth does sell a driver board that will work for this! problem is it's expensive as HELL! $49.00 it will fit into a pen style laser barrel.
http://www.mi-lasers.com/cgi-bin/sh...hstart=0&template=Templates/SearchResult.html

I'm also looking at a driver board for a LED flashlight that might work with a little modification.
http://dealextreme.com/details.dx/sku.3160

Since I am not that electrically knowledgable I'm having to ask other's if the driver boards I've mentioned will be sufficient. I will let everyone know when I find out more.

Click to expand...

The first board doesn't tell you what the output voltage is, the second board I think would be great... Especially the way they have it pictured with nothing on there except for the ramp chip and the diode I was thinking of working on one these... I'll have to do it sometime considering I have a few lying around gutted from other flashlights

--DDL[/quote]

Hello Daedal,
I have learned to think in terms of current when playing with diodes. Voltage doesn't matter to me and I hardly even look to see how much voltage I am applying. I always monitor current when playing around.

What Kenom is saying about driver boards providing stable current to the diode is true. However, one can get by using the proper resistor ( we are on exactly the same page with that one) and a capacitor.

I have been using a driver board on my home made laser and it is still running the same as the day I put it together. The driver I am using isn't adjustable. However with 4 nimh batteries it provides 240ma of current to the diode. I guess my point is by using a driver board, the diode is likely to last much longer, at least this has been my experience.


[/quote]

I definitely agree with you... The only thing I am thinking about here is wattage... Diode output is measured in mW... and that is Current * Voltage... 1W is 3V * .333 Amperes. If the diode is fine running at 2.5V at 300mA then that's 750mW, putting out close to 250mW and giving off 500mW as heat dissipation. If you power it at 6V at 300mA then it's putting out a steady 250mW as light and not having a problem... but all that excess is being given off as heat thus requiring more cooling. At this point it would be putting out 1550mW of heat! If the batteries supply 1.2V each then it's a bit less at 1120mW of heat... That is still more than double what the diode was made to give off... That can be limited using a voltage splitting resistor using the right values. The resistor would be giving off some heat though... which would or would not be as much as the diode depending on the resistor itself...

Again... the diode is fine giving off that much heat as long as it is running with something to give the heat off to (like an AixiZ module with some thermal epoxy) and a reasonable duty cycle. It would definitely not be any less than a minute or even more...

Hope that helps;
DDL

Not that you can't use voltage or input wattage to get a good idea of the power, but just FYI in figuring out the safe operating point of a diode, you're supposed to keep the current in spec with the datasheets. Input power and voltage may be estimated on a datasheet (after all, they're all roughly related), but its technically the current you need to tune your driver to.

Wow, those do look like nice LDs. Phew, I was about to order a CNI greenie and now I'm really tempted by these laser rocks. I've got an unused Meredith collimator assembly and mounting block though I'd need to get the 5.6 mm can (from 9 mm) thingie to work with this diode.

250 mW tho .. !!. Quarter watt of solid red power has a nice ring to it. And you could drop it down to a 'mere' 200 mW and with some luck get very good life from the part.

I also got this off the Sony link:

Despite this being a difficult device to design, we only had a short development period and the road to commercial release was perilous. However, thanks to much assistance from the staff and our cohesion as a group, we succeed in making it safely to commercial release. Our next step is to proceed with development aimed at even higher output to support two-layer discs.

Click to expand...

YES!!! More powerful diodes on the way!

I'm tentatively down for 5 of these - will let you know on Monday or Tuesday for certain.

So far, 38 have been bought and paid for !

http://www.dealextreme.com/details.dx/sku.3160

any reason you couldn't use one of these and add an extra resistor to drop the current?

I saw a current number, but not a voltage number - any idea how many volts they put out ?

Would you ship to South Africa?
and how much would that cost extra?
Jonno

Well, I am going to use Airmail for the overseas folks - and if it is TOO much, I wil lsend emails out begging for additional funds - I do not see it as costing too much more in all honesty - I Know that global priority runs close to $20 or more, so that is why I cut costs to include airmail in the price. Honestly, I really do not think it will be a problem - but if it does become a problem after I email asking for funds - just mark "return to sender" on the package when it is received, and I will refund the whole amount ! I know that was a long winded answer Sorry 'bout that ! ;D