DVD burners that rock for diodes.

Gazoo said:

Igor,
By warm I mean borderline to being hot..but not so hot I could not keep my finger on the cube. But keep in mind that even though the cube alone helps to keep the diode cool, I have no way of measuring the actual temp of the diode or even the module.

Click to expand...

I understand.. Since us humans percieve around 60°C as hot, i think this could be the temperature you felt.. The LD could have anywhere between 70° to 80°C at this point, since the cube seems quite big..

At this temperature, the output drop you described, is similiar to the one in the datasheet above..

Thanks for the info! It seems i really don't have anything to worry about..

Except for my cat that is...

IgorT

And your only heatsinking is an aixiz housing?


... I created a "pool" around the aixiz module, my laser is mounted in a flashlight, and the module is immersed in water, insulated of course... so, the LD is stuck in the module and module disperses the heat in water..




Nice results if you ask me.. Are these matches red? Or are they darker / you put a black spot on them??


sometimes I have dark matches to work with... but they're kinda hard to find... so I get the red ones and rub some barbecue charcoal on the head and BINGO! nice black head matches...



EDIT: Actually i can already give you a description of my next laser project right now.. You've seen my small laser enclosure, right? Well, i intend to make a hole in the next one, big enough to mount my small peltier through it (15x15mm) The LD assembly will be glued onto a copper plate, this will be mounted on the cold side of the peltier and outside of the plastic enclosure, i will attach a heatsink with fins to the hot side of the peltier...

Then i'll run the LD at 300mA and measure everything going on.. Then i might try 350... Maybe more (if i add a small fan to the peltiers heatsink).. By that time i should have quite a large collection of these free (but obviously strong) LDs.. So i'll test it to it's limits, and in case it dies, i'll know what not to do with the next one..

Oh, both the LD and the peltier will be running off the same power source - a small hobby grade LiPo inside the box.. I have a few stronger ones in case i need them, that would still fit the enclosure.


The other plan is to make some holes into the enclosure i have right now, directly beneath the fins of my heatsinks, and use a tiny pager motor with a tinly helicopter tail rotor, to provide some airflow.. I believe i could then run the current "phaser" at 300mA without any problems..



nice job, I don't have any TEC... but I think I will be getting some soon....
when I put my hands on a pioneer 112D I wanna try it really hard... and would be nice to have some cooler working... like a peltier.

good luck mate!!!!

IgorT said:

Thanks for the info! It seems i really don't have anything to worry about..

Except for my cat that is...

Click to expand...

LOL, you didn't laserblast you cat's fur head-on, did you?oo: If he is the black panther-like type of cat, you'd sure get an adequate uproarious reaction in a matter of minute

Phenol said:

LOL, you didn't laserblast you cat's fur head-on, did you?oo: If he is the black panther-like type of cat, you'd sure get an adequate uproarious reaction in a matter of minute

Click to expand...

The laser was on my desk, pointed across the room.. I went along the beam, measuring if it's "perfectly" straight.. Then i returned to my desk to turn it off, only to see my cat trying to catch the beam... She was facing the laser, so the beam was very visible to her, and obviously very interesting..

I would NEVER point it at her on purpose.. I love her..

I'm thinking about buying some blue contact lenses for her.. I don't think i could get the goggles to stay on her for any amount of time.

petah said:

sometimes I have dark matches to work with... but they're kinda hard to find... so I get the red ones and rub some barbecue charcoal on the head and BINGO! nice black head matches...

Click to expand...

So it's normal for the matches having to be black to get lit by a laser?

In this case, it seems my laser is working..

petah said:

nice job, I don't have any TEC... but I think I will be getting some soon....
when I put my hands on a pioneer 112D I wanna try it really hard... and would be nice to have some cooler working... like a peltier.

Click to expand...

Peltiers are very nice things to have when playing with lasers..

And they're not even all that expensive.. Especially, since you don't even need a very big one for a LD. You just need to make sure you are dispersing the heat away from it's hot side and it's gonna do a very good job.. If you forget this, however (or don't disperse enough) it can make things worse..

Since it's a heat "pump", the more heat you remove on the hot side, the more heat it can pump away from the cold side..

The one i bought was the smallest one they had 15x15mm 4W.. I believe it's powerfull enough to make my LD go from 45°C to room temp., or lower (in which case i could drive the LD a little stronger).. If not, i'll buy a bigger peltier and it'll still fit in my small enclosure..


Good luck!

IgorT

So it's normal for the matches having to be black to get lit by a laser?

In this case, it seems my laser is working..


yep mate, matches have to be dark "black is the best" you can't light a red head match with a red laser, or at least you won't do that easily, the reason why one thing is red is because it absorves any collor but red, it reflects the red....

Peltiers are very nice things to have when playing with lasers..

And they're not even all that expensive.. Especially, since you don't even need a very big one for a LD. You just need to make sure you are dispersing the heat away from it's hot side and it's gonna do a very good job.. If you forget this, however (or don't disperse enough) it can make things worse..


I know that buddy... and my duty cicles are short.... so I ain't worried about overheatin'.....

petah said:

the reason why one thing is red is because it absorves any collor but red, it reflects the red....

Click to expand...

Yeah, i know.. That's how i found my helicopter's metal flybar when it was lost in grass. At first i was crawling around on my knees for half an hour in full daylight and then gave up..
Then, in the evening, i remembered, how i was explaining to a friend, why in red light, you only see things that reflect red.. So i picked up my red LED flashlight, scanned the lawn for 20 seconds and found the flybar, since the metal reflected the red, while i was able to see THROUGH the grass.. I was actually dissapointed at how fast i found it.. That's how interesting the effect was.

petah said:

I know that buddy... and my duty cicles are short.... so I ain't worried about overheatin'.....

Click to expand...

I'm sorry, i wasn't implying that you don't.. Just hoping the explanation might help someone sooner or later..

I also stopped worrying about the heat, after getting to know my laser a bit better and reading that datasheet.. Now i know it's eating 300mA when the LiPo is full and 230mA when it's almost empty.. In both cases it can ignite a match in less than a second, and the temperatures are not that bad.. I'm actually starting to like this LD, and would recommend it to others.. (Samsung TS-H552 v.B or v.U)


When you get the peltier, i would be very interested in it's specs, how you set it up and the temperatures you measure..


BTW: What do you use, to measure the temp? I use a non-contact IR thermometer, but it's only exact when pointed at something dark.. Luckily my heatsinks are black, but i painted everything else aswell, to be able to measure at different spots..

IgorT said:

BTW: What do you use, to measure the temp? I use a non-contact IR thermometer, but it's only exact when pointed at something dark.. Luckily my heatsinks are black, but i painted everything else aswell, to be able to measure at different spots..

Click to expand...

I use a K-type thermocouple. Most multimeters have a temperature function based on a thermocouple probe.

IgorT said:

Yeah, i know.. That's how i found my helicopter's metal flybar when it was lost in grass. At first i was crawling around on my knees for half an hour in full daylight and then gave up..
Then, in the evening, i remembered, how i was explaining to a friend, why in red light, you only see things that reflect red.. So i picked up my red LED flashlight, scanned the lawn for 20 seconds and found the flybar, since the metal reflected the red, while i was able to see THROUGH the grass.. I was actually dissapointed at how fast i found it.. That's how interesting the effect was.


I'm sorry, i wasn't implying that you don't.. Just hoping the explanation might help someone sooner or later..

I also stopped worrying about the heat, after getting to know my laser a bit better and reading that datasheet.. Now i know it's eating 300mA when the LiPo is full and 230mA when it's almost empty.. In both cases it can ignite a match in less than a second, and the temperatures are not that bad.. I'm actually starting to like this LD, and would recommend it to others.. (Samsung TS-H552 v.B or v.U)


When you get the peltier, i would be very interested in it's specs, how you set it up and the temperatures you measure..


BTW: What do you use, to measure the temp? I use a non-contact IR thermometer, but it's only exact when pointed at something dark.. Luckily my heatsinks are black, but i painted everything else aswell, to be able to measure at different spots..

Click to expand...

It's OK buddy.. I got you!

and I use the same as you... a non-contact IR thermometer.

BTW: Guys, how dangerous are reflections from these lasers, from dark surfaces?

I noticed, my laser makes quite a little light show while burning through a piece of black painted paper for example..

Even a floppy disk reflects a surprising amount of light..

Any thoughts on this?

IgorT said:

BTW: Guys, how dangerous are reflections from these lasers, from dark surfaces?

I noticed, my laser makes quite a little light show while burning through a piece of black painted paper for example..

Even a floppy disk reflects a surprising amount of light..

Any thoughts on this?

Click to expand...

Yes, I have noticed that, too. While some plastics look black and mat, it is often times their texture that makes them diffuse reflectors. But when the hot dot melts a small spot, the surface underneath becomes glossy and reflective....
Do wear goggles. Specular reflections can be just as harmful, especially those from shiny polished metal objects...:mecry:

You guys may wanna look in the gb section. I'm putting together a gb on custom laser barrels. check it out in the GB section of the marketplace.

These are pictures of the emitting side of a chip-type LD/ found in cheap pointers/ magnified 500x. the first pic shows the LD pumped with ~1mA. It is not lasing yet.The pink surfce is the cleaved mirror facet with a scratch and speckles of contaminants. The second is the same thing with ambient lighting switched off. In the third one the LD is at about threshold current. Higher than that the webcamera became saturated. I'm temped to put a current spike thru this LD and literally see what happens

Just finished my DIY laser.










Used parts:

Laser module
http://www.dealextreme.com/details.dx/sku.5914

Host
http://www.dealextreme.com/details.dx/sku.2089

Converter
http://www.dealextreme.com/details.dx/sku.7302

Current limit
http://www.dealextreme.com/details.dx/sku.1885

Laser diode from Lite-On LH-20A1P

I have custom programmed the converter to get settable brigtnes and "effects" (uses PWM).
AMC7135 (2 peaces, one for laser, one for leds) soldered on board near inductor (in free space).

And there is one custom made ring, where the laser module is glued in with arctic adhesive, and then all screwed in the head.

MatajumotorS said:

I have custom programmed the converter to get settable brigtnes and "effects" (uses PWM).
AMC7135 (2 peaces, one for laser, one for leds) soldered on board near inductor (in free space).

Click to expand...

That step up converter looks really interesting.. With this, one powerfull 2700mAh NiMh could power the entire laser, and allow it to be in a very small enclosure.

What is the output voltage of the converter? Is it filtered enough, or do you think an additional cap is needed?

Nice work BTW.

You really tempted me with that converter, cos i like building things small but still want a regulated LD supply, so one AA NiMh would be much better than the 6 needed otherwise.. And MUCH cheaper than a 2 cell LiPo. I think i'll be getting a few.


EDIT: Is it a two layered board or does it have three layers? I've seen some complaints on DX about it not coming pre-assembled or missing some parts.. Now i'm not so sure anymore..

the converter is 5v output, there are two one layer boards.
I will try 19-mode coverter when will receive it, it is more powerful and has settable output voltage.

MatajumotorS said:

the converter is 5v output, there are two one layer boards.
I will try 19-mode coverter when will receive it, it is more powerful and has settable output voltage.

Click to expand...

If it's 5V then a 317 current regulator wouldn't work with it..

But if the output is a stable 5V, even when the battery voltage is dropping, all i'd need on the output is a current limiting resistor and a cap or two.. It could even be used to power a blueray..

Do you have a link to that other converter?

Thanks!

Igor

carmangary said:

Hi all. I have read through here but I am still unsure of which one will do what I want. I need one to be able to do 200mw continuous. I will have it heatsinked of course. Has anyone run that hard continuously without it failing?

Click to expand...

The Pioneer and the LiteOn should both be able to do that..

The one i'm currently using (from a Samsung TS-H552) also seems to be capable of this, but it is possible that i have a freak diode on my hands..


BTW: What do you need exactly 200mW of output power for?

IgorT said:

If it's 5V then a 317 current regulator wouldn't work with it..

But if the output is a stable 5V, even when the battery voltage is dropping, all i'd need on the output is a current limiting resistor and a cap or two.. It could even be used to power a blueray..

Do you have a link to that other converter?

Thanks!

Igor

Click to expand...

Here is the link: http://www.dealextreme.com/details.dx/sku.7882
with this you don't need no resistors or else. You can set the voltage to obtain needed current. Ofcourse it will warry because of temperature a little.
Other way is to use AMC7135 like me, you'll get 350ma limit, or you can add a resistor in paralel with ld to drop not needed current(if you need less than 350ma) like someone suggested before here.

MatajumotorS said:

Here is the link: http://www.dealextreme.com/details.dx/sku.7882
with this you don't need no resistors or else. You can set the voltage to obtain needed current. Ofcourse it will warry because of temperature a little.

Click to expand...

If it's possible to set it to 6V, i'd rather use a LM317 current regulator after it, to achieve constant current, even when it would start dropping otherwise due to temp..

But i understand what you mean.. If it's fine-tunable, you could just use it directly.. I would just add a 1 Ohm resistor for measuring the current, and a cap or to, for additional filtering and protection..

The variations from the temp. are probably neglectable.. I don't think anyone would even notice them..

Thanks for the link BTW.