Group buy for 16X dvd burner diodes !

Awesome! Thanks so much for organizing this SenKat! I am having butterflies in my stomach about now.... Excited!!!

Oh MAN those things look so awesome all packed up nice like that! If I was smart enough I would buy a TON more and make a bunch of laser modules just to play with and sell to my friends. And just to think, each one of those babies could all turn into lasers worth a lot more than what we payed for them!

styropyro said:

Oh MAN those things look so awesome all packed up nice like that! If I was smart enough I would buy a TON more and make a bunch of laser modules just to play with and sell to my friends. And just to think, each one of those babies could all turn into lasers worth a lot more than what we payed for them!

Click to expand...

You are learning quickly, young Jedi. Use the power of the force, and start your own business... ;D

sweet they are there cant wait till they get here lol

Fire up the transporter Scotty !!!!

Mike

Wow Greg! Nice pics. Can't wait to play around with my diodes.  

Okay, I have a quick question though. When you add a capacitor to the circuit, it gives the diode a slow "start up" so to speak, right? Well I've been using 6.3 volt 100uf capacitors, and I want to play around with pumping high ammounts of current through one of the diodes (like VaThInK on CPF does) with a heatsinked peliter to cool the module. So my question is, can I use a high capacitance capacitor (like 1000uf or more) to give a very slow ramp up to full current at around 500-800mA. I will probably use the AixiZ wall wart supply (supposedly regulated at 3.2 Volts @ 500mA) but if any of you guys know of a good power supply I'm open to suggestions. Unfortunately I can't afford a benchtop DC Power Supply so that's out of the question for now.

Thinking it over, it would probably be better to use a potentiometer, but I don't really want to have to fool with having to slowly turn the current up.

It sucks having a limited electronics knowledge.  :'(

yuip said:

Wow Greg! Nice pics. Can't wait to play around with my diodes.

Okay, I have a quick question though. When you add a capacitor to the circuit, it gives the diode a slow "start up" so to speak, right? Well I've been using 6.3 volt 100uf capacitors, and I want to play around with pumping high ammounts of current through one of the diodes (like VaThInK on CPF does) with a heatsinked peliter to cool the module. So my question is, can I use a high capacitance capacitor (like 1000uf or more) to give a very slow ramp up to full current at around 500-800mA. I will probably use the AixiZ wall wart supply (supposedly regulated at 3.2 Volts @ 500mA) but if any of you guys know of a good power supply I'm open to suggestions. Unfortunately I can't afford a benchtop DC Power Supply so that's out of the question for now.

Thinking it over, it would probably be better to use a potentiometer, but I don't really want to have to fool with having to slowly turn the current up.

It sucks having a limited electronics knowledge. :'(

Click to expand...

Even if you cooled the diode with any method you wanted they still have a limit, I'd suggest going up with power by smaller steps, if you really don't care about blowing it up then have fun

My thoughts are a bigger capacitor will not necessarily be better. But this is why we all experiment, to find out what works and what does not. The diode VaThink is using is an open can diode from a 20X DVD burner. It is bound to have different characteristics from these diodes. I am also using an open can and it is truly sexy..ha..ha. But it did come at the cost of having to dissect an almost new DVD burner. I ordered an exact replacement for my computer which cam yesterday. Also take note of Bimmers post at CPF as it does carry a lot of merit.

Anyway, while a capacitor will prevent a surge, the equally important aspect is of course current. I am in the same shoes and do want to try the same experiment. What I am thinking about doing is getting some LM317T's. These are variable regulators, are very cheap and easy to use. And all of the parts can be found at Radio Shack to build this regulator. If you open the PDF file from the following link, you will see the specs including sample circuit diagrams. It is very easy to work with:

http://www.onsemi.com/pub/Collateral/LM317-D.PDF

I think we need to use a variable power supply so we can easily determine the appx. current we can drive these things with before they turn into an LED. Especially when experimenting with TEC and what not.

My question would be this. We know the diode can easily put out 250mw if pulsed at 40ns, and not kill it. If we use any regulation circuitry that is PWM (Pulse Width Modulation) would this extend the life of the diode as opposed to using continuous wave power? I would think so but I am interested in others thoughts. What would it take to make a circuit that pulses at 40ns. And I wonder how much we could overdrive the diode when pulsed at 40ns....or any circuit that uses PWM? I really need to get a scope..lol.

paper183 said:

[quote author=yuip link=1183788027/210#213 date=1185554512]Wow Greg! Nice pics. Can't wait to play around with my diodes.  

Okay, I have a quick question though. When you add a capacitor to the circuit, it gives the diode a slow "start up" so to speak, right? Well I've been using 6.3 volt 100uf capacitors, and I want to play around with pumping high ammounts of current through one of the diodes (like VaThInK on CPF does) with a heatsinked peliter to cool the module. So my question is, can I use a high capacitance capacitor (like 1000uf or more) to give a very slow ramp up to full current at around 500-800mA. I will probably use the AixiZ wall wart supply (supposedly regulated at 3.2 Volts @ 500mA) but if any of you guys know of a good power supply I'm open to suggestions. Unfortunately I can't afford a benchtop DC Power Supply so that's out of the question for now.

Thinking it over, it would probably be better to use a potentiometer, but I don't really want to have to fool with having to slowly turn the current up.

It sucks having a limited electronics knowledge.  :'(

Click to expand...

Even if you cooled the diode with any method you wanted they still have a limit, I'd suggest going up with power by smaller steps, if you really don't care about blowing it up then have fun [/quote]

Yeah, that's what I figured.

Thanks for your help Gazoo, I'll look into making a circuit with a LM317T. I might wind up buying the Meredith Instruments driver though, since it was designed for laser diodes. But then again, it's $50.

A 40ns pulse followed by 40ns off period equates to a 12.5MHz square wave.  That's a very high frequency to generate for a minimimum of pcb space.

It's OK to pulse at a longer period than 40ns as long as you respocet the max power capacity of the device.  What is important is the max current at various pulse duty cycles.  The Datasheet PDF from Sony does not give that figure.  

Greg, did they ship a more detailed datasheet (with pinout) with the LDs?

Paul

yuip said:

Thanks for your help Gazoo, I'll look into making a circuit with a LM317T. I might wind up buying the Meredith Instruments driver though, since it was designed for laser diodes. But then again, it's $50.

Click to expand...

I have been tempted to get that driver too. The only problem I have with it is it costs 3 to 4 times more than it should. And we don't know what all the specs are on it. But it is still tempting.

Oh, I have one of those MI lasers drivers. I never bothered figuring out how to use it though and I have no idea where I put it. If there's some specific thing you want me to test I can try digging it out though.

Well, I would not want you to go through too much trouble.... But if you have a scope I would be interested in the frequency of the voltage.

yuip said:

Wow Greg! Nice pics. Can't wait to play around with my diodes.

Okay, I have a quick question though. When you add a capacitor to the circuit, it gives the diode a slow "start up" so to speak, right? Well I've been using 6.3 volt 100uf capacitors, and I want to play around with pumping high ammounts of current through one of the diodes (like VaThInK on CPF does) with a heatsinked peliter to cool the module. So my question is, can I use a high capacitance capacitor (like 1000uf or more) to give a very slow ramp up to full current at around 500-800mA. I will probably use the AixiZ wall wart supply (supposedly regulated at 3.2 Volts @ 500mA) but if any of you guys know of a good power supply I'm open to suggestions. Unfortunately I can't afford a benchtop DC Power Supply so that's out of the question for now.

Thinking it over, it would probably be better to use a potentiometer, but I don't really want to have to fool with having to slowly turn the current up.

It sucks having a limited electronics knowledge. :'(

Click to expand...

I think what you're trying to do is to create a bit of a delayed start?

That kind of thing can easily be done by using a larger capacitor, such as the one you suggested, connected in series with a nice, big, resistor...

What that does is effectively add a resistance to your circuit thus slowing down the ramping of the capacitor. Thus slowly charging the capacitor, once the capacitor is charged, then your current starts going into the diode.

P.S. 500mA = instant death! 300mA is probably instant death! Just so you know

GL;
DDL

Hi all, First post.... I have been looking for a red that will not be swamped by my 10mw green for a home made projector.

Now I have a post under my belt I will PM you for more details.

Regards rog8811

how many of the lasers are remaining? I sure would like to pick up four of them.