Sony 20x burners $24 at Newegg

[IgorT]

In addition to the Sony, there is a LiteOn 20x burner available for $23 with free shipping too.

The LiteOns most likely contain short chip open cans..

Not sure if there is any difference in their capabilities, but the general oppinion is, that long is better in this case.. More surface area for heat transfer and all...

 

[IgorT]

I ordered a couple more.

How many do you need?!?

Well, if they cost me so little, i would have bought two, but i had to pay $US 43 for one...


And the shop i bought it from didn't give me an invoice on my company, and they are not answering my emails.. They also lied about when they sent it...



BTW: Gazoo, what would be the best mount, that would grab my open can from all around and be flat on the bottom, to attach to the peltier?

 

[Gazoo]

That was my problem too and is why I resorted to the meredith module for my labby:

http://www.mi-lasers.com/cgi-bin/shopper.cgi?search=action&keywords=diode_optics

I ordered a couple of mounting blocks and my problem was solved. Since I have been using the modules I have been very happy with the ones that come with the glass lens, and I will be using one in my MXDL build.

BTW, as you know when a diode heats up, the output drops considerably. So once you get that baby cooled, it should be visibly brighter but not by much. If I recall correctly it takes 4 times the power to appear twice as bright. So a 400mw red laser would appear about twice as bright as a 100mw red laser, and that has been pretty much what I have experienced.

Regarding the PSU, I don't believe I have lost a red diode yet on account of ESD running through the supply. I do recall VaThink was using a PSU intended for a computer to power his peltier and open can. Perhaps this would be the ideal solution.

http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply

 

[IgorT]

BTW, as you know when a diode heats up, the output drops considerably. So once you get that baby cooled, it should be visibly brighter but not by much. If I recall correctly it takes 4 times the power to appear twice as bright. So a 400mw red laser would appear about twice as bright as a 100mw red laser, and that has been pretty much what I have experienced.

I mounted it in a vice this time, and powered it at 410mA and it didn't even get warm on the outside... The vice pulled out all the heat, even with a minumum surface contact...

I was thinking of using a "dremel" to grind one side of the module flat and glue it to a peltier sized metal plate and this on the peltier.

I'll look into the Meredith modules, but i recall they are very expensive...

Regarding the PSU, I don't believe I have lost a red diode yet on account of ESD running through the supply. I do recall VaThink was using a PSU intended for a computer to power his peltier and open can. Perhaps this would be the ideal solution.

I just went through that thread, and if i'm not mistaken, he was running it off the 5V using only a resistor...

I thought you were a big proponent of current regulation.. I mean, you managed to convince me as well.


BTW: My peltier cooled open can is not going to be a labby.. It's gonna be a very small portable "pointer"... I'm even gonna make my own enclosure to make it all fit...



Anyway, i lost three reds on a PSU.. And two Blue Rays.. Of course the latter are MUCH more sensitive, i agree and the reds probably died for other reasons, but now that i'm using only battery power, i'm not worried about touching the module for repositioning anymore. I still ground myself when building, but once it's in the circuit, i feel completelly safe. This wasn't the case before, but i agree it's not just ESD. It's also a bit of experience by now..

I'm also using low ESR and ESL ceramic and tantalum capacitors directly on the LDs now, since they behave differently than a similiar through-hole cap, simply because they have no leads.

I finally feel like i'm capable of building lasers without killing them anymore, and it feels good.

 

[Abray]

this brings up a point I've been worrying about.

I posted in another thread, but that other thread appears to be dead, so

how can I protect the diode from being ESD killed?? how exactly could I ground myself so I won't shock the diode?

 

[pullbangdead]

this brings up a point I've been worrying about.

I posted in another thread, but that other thread appears to be dead, so

how can I protect the diode from being ESD killed?? how exactly could I ground myself so I won't shock the diode?

Basically, you need your hands and anything else that touches the diode to be grounded, all the way to an earth ground. You can buy grounding wrist-straps very cheaply (I've even seen people on here giving them away), you just strap it on your wrist and attach it with an alligator clip to something that you are certain is grounded, like exposed metal on a desktop computer case. If you're working in a basement, cold water pipes are often a very good place to find a good earth ground (not hot water pipes, as they may be "floating" above ground due to a hot water heater). You can make a rudimentary static bracelet with some wire, just tie exposed metal around your wrist securely, and attach the other end to something that is grounded. As long as there is continuity between your hand and ground, you're relatively safe. There are also work mats that can be grounded that provide an even safer environment from ESD.

ESD hasn't been of much concern for red diodes, it's usually just good practice though to be grounded when working with electronics. It's also sometimes good practice to touch your tools to something that is grounded when picking them up to bleed off excess charge, it's easy and can't hurt anything. Blu-ray diodes, or so I've read, are the real ESD-sensitive diodes taht you must use care around, like a good bracelet and a mat, as well as possibly an ESD-safe soldering iron (these ensure that the iron and especially its tip are grounded, reducing the risk of your iron zapping your diodes).

Just for a reference, diodes run at less than 10 volts (round number). These are the typical voltages for static electricity "events":

If you can feel a shock, it's more than 3000 volts
If you can hear a shock, it's more than 5000 volts
If you can see a spark, it's more than 8000 volts

So you can see why static can be bad, but diodes, on the whole, are pretty sturdy against ESD when packaged as well as they typically are.

 

[Gazoo]

I just went through that thread, and if i'm not mistaken, he was running it off the 5V using only a resistor...

I thought you were a big proponent of current regulation.. I mean, you managed to convince me as well.

;D...Yes I am a proponent of current regulation. But I was thinking if using the PSU from a computer to power the driver..he..he.

Someday I too would like to build a flashlight and cool it with a peltier. Your idea about using a dremel is good. I was using the smaller aixiz module when I did my first TEC and didn't even bother to file it down. I used arctic silver epoxy and it held it in place and it did work out quite well, but eventually the peltier fell apart. I think this was due to stress caused by focusing it when I had my meredith glued to it.

 

[Gazoo]

And here is the pic of it with the smaller aizix module glued to it:

 

[Gazoo]

And this is what I am currently using....

 

[IgorT]

how can I protect the diode from being ESD killed?? how exactly could I ground myself so I won't shock the diode?

Well, your question was mainly answered already... Just wear a grounded wrist strap while building. You can make one yourself, if you have elastic band, some velcro, a piece of metal and a wire with an aligator clip..


The reason i was talking about PSU "dangers" was, because i killed two blue rays (and some reds, but probably for other reasons), by powering their drivers from a PSU.. While building i was grounded, but i thought they would be safe in a circuit and with caps directly on their leads..


So when i was aligning the BR beam with a 5mW red beam to compare them, i wasn't grounded anymore.. So i went along the beams to look against them, and they were not properly aligned for a photo i was trying to make, so i went back, touched the AixiZ module the Blue Ray was in, and it suddenly lost 2/3 - 3/4 of it's power..


That's why i don't use a PSU to power laser drivers anymore.. I only use battery power.. A PSU provides a path to the ground for ESD.. A battery doesn't..
Reds are much less sensitive, but on the other hand, maybe people weren't pulling such huge sparks as me, that fatefull day..


But now i don't have to worry about ESD anymore, since it has nowhere to go to, without a ground path... I still touch the radiator before touching anything else, while building, but touching a finished laser isn't dangerous anymore.



I had a big 12V lead battery, and didn't know what to do with it, so i turned it into a safe power supply for my experiments.. This is how i do everything laser related now.

 

[IgorT]

Someday I too would like to build a flashlight and cool it with a peltier.

How big is that peltier of yours anyway? It doesn't look that huge.. Mine is 15x15mm, but i just snatched all the 20x20mm i could find on e-bay as well.. (three )

The 20mm are thinner, but more powerfull, but i have to see them, before i decide and measure their power from a single Ni-MH cell.. But it would be great, having the power of a labby in a tiny portable.. I'm thinking of using several switches for different power settings and i would also like to take appart a small thermometer and incorporate it in, so i see the temperature of the module on a tiny display...

All i'm missing right now is the Li-Pos from DX..

Your idea about using a dremel is good. I was using the smaller aixiz module when I did my first TEC and didn't even bother to file it down. I used arctic silver epoxy and it held it in place and it did work out quite well

I think it'll do fine, because the vice was only holding a very small area on both sides and still managed to suck all the heat out.

At first i thought it would be good to have some mass around the head of the aixiz module, but itself is massive enough to cool the LD, as long as it is touching something.

So i'll just go with a flat sided aixiz module.

, but eventually the peltier fell apart. I think this was due to stress caused by focusing it when I had my meredith glued to it.

I didn't know they were that sensitive.. Need to make the mount rigid so the peltier doesn't take the stress..

Thanks for the heads up!

 

[Gazoo]

I don't remember he dimensions but it was tiny. And man did it get cold. If you notice it is a stacked type peltier, so it really did work well with a very low amount of current.

As far as mass goes the aixiz module will provide ample mass for cooling. I would be more concerned about mass for heatsinking the hot side of the peltier in a flashlight application. I will be looking forward to your design.

 

[cyclonite]

Hi guys,

unfortunately Newegg.com is an American site Can't seem to find that drive here in the UK. Can someone who has bought the drive please confirm that the model is 'AD-7190A'?

Thanks.

 

[IgorT]

As far as mass goes the aixiz module will provide ample mass for cooling. I would be more concerned about mass for heatsinking the hot side of the peltier in a flashlight application. I will be looking forward to your design.

Yes, i figured that out when i just had the open can module held in some spring loaded "pliars", that were only touching it with a very small area, since the module is round and their tip is as well. Still, it didn't get hot at all..

So i'll grind the side of the aixiz away to make it flat, and glue it to an alluminum square, so it covers the entire cold surface of the peltier.. Don't want to waste any of it's heat pumping power..


The peltier's hot side will be cooled by a pager motor driven propeller, blowing on a heatsink with lot's of thin fins. This way, the heatsink can be smaller... If it's not enough, i'll also glue some chunks of metal to it, in a way, that it all fits in the DIY enclosure.

I didn't get a chance to start mounting all this together yet, due to work, but i just finished the SEPIC converter, and it works great! It's only 25x19mm big, and i could make it smaller, now that i have all the right components.. But it's so thin due to all SMD components, that it doesn't really matter.. This will probably be the open can's driver.

When i'm done i'll post the pics.

 

[IgorT]

unfortunately Newegg.com is an American site  Can't seem to find that drive here in the UK. Can someone who has bought the drive please confirm that the model is 'AD-7190A'?

Well, i didn't find the same one in Slovenia either, but i found AD-7191 and it contains the same LD - long chip open can. It's not very easy to get out tho.. Need to be patient and carefull.
There were also some Sony NEC 7200 models available, but i didn't order those, for fear of what i'd find... But it might be the same..

On the other hand, there are other drives that contain the same LD.. You should do some searching. Maybe look into CPF (best DVD for laser diode thread) for a list of drives and diodes you can find in them...

 

[cyclonite]

Hi IgorT,

Sorry I can't find that thread, could you pls provide the link if you have it off hand?

Thanks.