Building a laser using a KES-400a , need help!

[Pyro01]

I've tried the search function and I've found lots of threads mentioning KES-400a laser diodes, but no tutorials on how to build them.  I'm not looking on how to build a laser with the 803t diode!  Seeing as how the laser will be relatively low-powered, I believe a maximum of 30mw, does this thing even need a driver in order to run it?  Basically, I'm having a hard time trying to determine what parts I need, so far I have:

Aixiz laser module
KES-400a Blu-ray diode sled

I was hoping to use a Dorcy Jr. as the housing.  If anyone can give me any insight on what parts I need to run this low power diode it'd be greatly appreciated.  The last thing I want to do is rely on only resistors to prevent the diode from blowing out.  Thanks for the help guys!

 

[lasersbee]

I've tried the search function and I've found lots of threads mentioning KES-400a laser diodes, but no tutorials on how to build them.  I'm not looking on how to build a laser with the 803t diode!  Seeing as how the laser will be relatively low-powered, I believe a maximum of 30mw, [highlight]does this thing even need a driver in order to run it?[/highlight]  Basically, I'm having a hard time trying to determine what parts I need, so far I have:

Aixiz laser module
KES-400a Blu-ray diode sled

I was hoping to use a Dorcy Jr. as the housing.  If anyone can give me any insight on what parts I need to run this low power diode it'd be greatly appreciated.  The last thing I want to do is rely on only resistors to prevent the diode from blowing out.  Thanks for the help guys!

If you are asking this question.... then you have not done enough research/reading
on the Forum... the KipKay "resistor driver" is not the way to go if you plan on seeing
a laser beam for a while...

Jerry

 

[Pyro01]

I was not planning on making the kipkay resistor drive, I guess I as trying to make the point that I'd never use it. So my question remains, what would you use to regulate the current for such a low power diode, as well as the other components that you would need. I have the diode and the aixiz housing at the moment.

 

[chipdouglas]

Yes you need to, because batteries aren't generally regulated. There would be too much current. The LD would fry. low powered or high powered it does not matter. All LD's need regulated power.

 

[Pyro01]

Yes you need to, because batteries aren't generally regulated. There would be too much current. The LD would fry.  low powered or high powered it does not matter. All LD's need regulated power.

Any recommendations for current regulation of a KES-400a PS3 LD? A specific component name would be monstrously helpful ;D

 

[ElektroFreak]

LM317. Just look up "DDL driver" in the search portion of the forum. An LM317 driver can be used to drive any laser diode up to 1.5A of current depending on how you set the circuit up. It's very simple to build and can be done using Radio Shack components.

Ordinarily I also recommend doing your own research here, but since you are new i'll point you in the right direction: http://www.laserpointerforums.com/forums/YaBB.pl?num=1185701612

 

[Pyro01]

Thank you everyone, I realized the reason why I couldn't find any information was that I hadn't thought of the right keywords for the search. This should get me started and hopefully I'll be able to take care of everything myself from now on.

 

[ElektroFreak]

Thank you everyone, I realized the reason why I couldn't find any information was that I hadn't thought of the right keywords for the search.  This should get me started and hopefully I'll be able to take care of everything myself from now on.

No need to take care of everything yourself.. We're always happy to answer questions, it's just that when we see a question that has already been answered many times before, we respond by pointing out the fact that proper usage of the forums resources can help you without any input from us..

 

[rog8811]

There is another driver you could look at, I used this one on all but one of my kes 400 builds, you set it up in exactly the same way as a DDL driver, with a test load, the advantage is you can fit it into the aixiz module.

Regards rog8811

 

[pianoman2011]

Here's a forum I made about the KES-400A diode... http://www.laserpointerforums.com/forums/YaBB.pl?action=shownotify

To sum some important information up:

- Limit the current to a max of 40mA.

- If possible, try using a plastic flashlight or some other housing where you can install a switch on the side (unless you think you can cut through the side of the Dorcy). If you install a switch that routes your driver's "+" output to two different wires, you can attach one wire to the violet anode lead and one wire to the red anode lead. This way you can flip the switch and with a bit of focusing, your laser will change from red to violet or vice-versa!

- I think the driver you want to use is a DDL driver or a Rckstr driver. You sounds like you are a beginner with this stuff (correct me if I'm wrong) an d so using the Flexdrive, which requires some modification for whatever current you want to use, might be a bad idea. And you will want to test current with a dummy load.

- Do not run both anodes at once unless you want to drastically reduce the life of the diode.

Ask any more questions... I will answer.

-Jakob

 

[Pyro01]

There is another driver you could look at, I used this one on all but one of my kes 400 builds, you set it up in exactly the same way as a DDL driver, with a test load, the advantage is you can fit it into the aixiz module.

Regards rog8811

Now is that a 10 microferrat +16 V Max ceramic disk capacitor?  

And to pianoman2011, I'm new to laser circuitry, but not new to electronics.  Basically, I don't know a whole lot about how drivers tend to work, but if you gave me a schematic, i could sure build ya one .  I going to school in a remote town with only one Radioshack, whenever they're out of a part you either gotta order it online, or drive a minimum of 50 miles to another store. I don't think I'll be able to find a Dorcy Jr. without ordering one online though either.  

One last question though, I've seen people say to use anywhere from 4.5-9 volts to drive one of these laser diodes.  Is it just specific to what that diode might require or how much I'm willing to push out of it?  I'd be happy around 20-25 mW of power, and I believe in order to achieve 25 mW of power, with a supplied voltage of 6V, you'd need about 1.42k ohms of resistance.  I think I did my math right, but it has been a while. The current would come out to be 42 mA, so I might have to increase the resistance a little, in order to lower the wattage and get it to a safe operating range of 30-40 mA, according to Sam's Laser FAQ.

 

[rog8811]

Now is that a 10 microfarad +16 V Max ceramic disk capacitor?  
I used a tantalum of that value.
 
One last question though, I've seen people say to use anywhere from 4.5-9 volts to drive one of these laser diodes.  Is it just specific to what that diode might require or how much I'm willing to push out of it?
4.5v is the operating voltage of the LD, the required input voltage depends on the regulator you use, 2 X 10440 (3.7v rechargables) will cover all of the bases.

I'd be happy around 20-25 mW of power, and I believe in order to achieve 25 mW of power, with a supplied voltage of 6V, you'd need about 1.42k ohms of resistance.  I think I did my math right, but it has been a while.  The current would come out to be 42 mA, so I might have to increase the resistance a little, in order to lower the wattage and get it to a safe operating range of 30-40 mA, according to Sam's Laser FAQ.
If you are saying that you are just going to put a 1k4 resistor between the battery and the LD all I can say is good luck, you will need it. Build a driver with a pot, set it up with a test load then swap out the pot for a fixed resistor of the correct value.

Regards rog8811

 

[Pyro01]

Yeah, I figured I had to narrow it down with a potentiometer, what I was asking was if it sounded right, about an estimated resistance of 1.4k ohm. I have a driver already built and ready to go, but I need to get a bigger potentiometer, right now I only had a 25 ohm potentiometer in there because they didn't have a 100 ohm. I should probly just go buy a bigger potentiometer. I suppose the best way to get accurate power estimates is to just run a test load and test it with a multimeter, all that other stuff I did before was just the math.

 

[rog8811]

1K4 sounds about a factor of 1000 out, I know the circuit I posted is a different reg but it only needs a 22r resistor to get the output right. The best way to be sure is with a test load.
Your 25ohm pot should do the job fine.

Regards rog8811

 

[pianoman2011]

And to pianoman2011, I'm new to laser circuitry, but not new to electronics.  Basically, I don't know a whole lot about how drivers tend to work, but if you gave me a schematic, i could sure build ya one .  I going to school in a remote town with only one Radioshack, whenever they're out of a part you either gotta order it online, or drive a minimum of 50 miles to another store. I don't think I'll be able to find a Dorcy Jr. without ordering one online though either.  

One last question though, I've seen people say to use anywhere from 4.5-9 volts to drive one of these laser diodes.  Is it just specific to what that diode might require or how much I'm willing to push out of it?  I'd be happy around 20-25 mW of power, and I believe in order to achieve 25 mW of power, with a supplied voltage of 6V, you'd need about 1.42k ohms of resistance.  I think I did my math right, but it has been a while.  The current would come out to be 42 mA, so I might have to increase the resistance a little, in order to lower the wattage and get it to a safe operating range of 30-40 mA, according to Sam's Laser FAQ.

Well it is good that you are not entering this hobby entirely new to electronics. That means that you should be able to read the schematic below! This switch attached to the + output conveys my idea about having a switchable red/violet laser. If you have a decent RadioShack, they might have an LM317 or LM317T, some PCB, some resistors, some 100-500ohm pots, some IN4001(?) diodes, and a couple of similarly rated capacitors as the ones that are in the schematic. If you really need, I could drop some of the caps and pots in an envelope and send you some. And if you do want to do the 2 colored laser, don’t use a Dorcy Junior. Use a project box from your local RadioShack or an Altoids tin or something to that effect.

If you do use the drive I have given you the schematic for, use a fully charged 9V battery to power it. This can be kind of costly after burning through five or six 9V batteries, so eventually I bought a rechargeable energizer 9V battery (rated 8.4V but actually cranking out 9.2V on a full charge!). I suggest you save yourself some 9V batteries and go ahead and do that now. But how far you are willing to push the diode is not based on volts but on mA’s. You need to make sure to supply the diode with the right amount of mA’s or it will blow: In this case ~35-40mA. And I think your math is somehow wrong. In my driver, when the pot is cranked up to full resistance, it only supplies around 10mA. So I KNOW that you need <100ohms of resistance. Any questions, just ask. Schematic for driver is below! Enjoy building!

-Jakob

 

[FireMyLaser]

Don't use that schematic, it will blow your diode the very moment you flip that switch. You must NEVER break the circuit on the output on a constant current driver! The driver will try to regulate the voltage all the way up to keep the current constant. Instead use two drivers and put the switch on the input of the driver(s).
Since there seem to be some confusion about the maths, here's two examples:

For the DDL driver:

R = V / I:
1.25V / 0.04A = 31.25 ohms. (Always go for the nearest HIGHER common value.)

W = U * I:
1.25V * 0.04A = 0.05 Watt. (Always go for the nearest HIGHER common value.)


And here's how for the "kipkay-driver". Works good for lower current standard LEDs.

R = V / I:
9V - 4.5V =  4.5V / 0.04A = 112.5 ohms.

W = U * I:
4.5V * 0.04 = 0.18 Watt.

Jakob, please don' post things you don't really have a grip on. Pyro01, what you need to do is just look some more, there's a TON of great info on how to use this diode.