Noob building Laser

[vincenthooi]

so now i have what appears to be a crude DDL driver(lm317, 10ohm resistor, 47uf cap, 100ohm pot,1n4001 diode),
i have a few questions
1: can i use 4x AA battery to power the dvd burner diode with the Driver?
2: what kind of output will i be getting from 4x AA batteries with pot at maximum?
3: will reverse polarity while connecting the diode kill the diode outright?

 

[GooeyGus]

so now i have what appears to be a crude DDL driver(lm317, 10ohm resistor, 47uf cap, 100ohm pot,1n4001 diode),  
i have a few questions
1: can i use 4x AA battery to power the dvd burner diode with the Driver?
2: what kind of output will i be getting from 4x AA batteries with pot at maximum?
3: will reverse polarity while connecting the diode kill the diode outright?

1) Yes, as 6v is the MINIMUM, but the laser will drop in power very quickly. I would recommend at least 6 AA's, or a couple 3.6v lithiums. This way you can get a high level of current, with a somewhat decent run time before the driver drops out of regulation.

2) with the 10ohm resistor the highest current you can get with the LM317 is 125mA. I would add two more 10ohm resistors in parallel, giving you a total of 3.33ohms when the pot is set to least resistance. This will give you the ability to go to ~375mA. Or, if you're feeling risky, you can take out the resistors all together and just use the pot. Thats what I do, but I measure my current very carefully while adjusting.

3) With the driver you have set up, no. the 1N4001 diode protects you from killing the diode due to reverse polarity. Without the diode I'm pretty sure it would kill it but to be honest I've never hooked one up the wrong way, so I'm not 100% sure.

Hope that helped!

 

[vincenthooi]

what is the voltage and current that dvd burner diodes uses?

 

[chido]

The current depends on the type of diode. I recommend to people not to go over 350mA when using a SenKat LD, for long open cans, 420mA has been found to be the sweet spot, for short open cans, I recommend you don't go over 300mA, and so on......
As for the voltage, you don't need to worry about it, the LD will take whatever voltage it needs to work, all you need to worry about is the current. Forget about the voltage.

 

[vincenthooi]

thanks chido. Can anyone show me macro shots on how to differentiate between long open can and short ones?

thanks

 

[vincenthooi]

what kind of driver can i build to make it possible to create a burning laser from pioneer 115d at 250mw+ output with 4 aa batteries?

 

[chido]

Sure, (not exactly macro shots but better than nothing) ;D

Here's a long open can:

And here's a short open can:

The physical difference is that one has a longer dye than the other. (hence their names)
The short open can pic is bad but you can see a line that goes through the dye, right after that line you'll see that the dye ends and if you compare it to the first picture you'll see that the diode in the second pic has a shorter dye.

Dye length isn't the only difference, long open can diodes are way more powerful than short open cans.

Here's a power graph comparing both diodes:

You can clearly see the difference in power.

Hope this helps.

 

[chido]

what kind of driver can i build to make it possible to create a burning laser from pioneer 115d at 250mw+ output with 4 aa batteries?

The only driver you can make is the DDL driver, but you need 7v+ to power it. If you want to power a red diode without having to use a lot of batteries then I recommend you get a flexdrive. You could easily power it with 3AAs, 2AAs if you want but I don't think they'll last more than a couple of minutes.
The sweet spot for these long open cans is 420mA, that should give you around 240 - 250mW with a regular acrylic lens which comes with the aixiz modules, and around 280mW with a meredith glass lens.
BTW, if you use the meredith module then you have to buy this adapter, the meredith modules are made for 9mm diodes, and the diodes we use are 5.6mm. (including the open cans of course)

 

[vincenthooi]

woah thanks again for the pictures.
flexdrives are quite expensive.. i think i wil skip on the driver, and use 6 aa on the ddl driver instead.
anything i should know before i buy the drive to cannibalize?(pioneer 115 is long open can right?) ;D

 

[chido]

lol, yes the diode from a pioneer 115D is a long open can, here's what you'll be expecting when you get the drive. (thanks for the tutorial Andy)

 

[GooeyGus]

woah thanks again for the pictures.
flexdrives are quite expensive.. i think i wil skip on the driver, and use 6 aa on the ddl driver instead.
anything i should know before i buy  the drive to cannibalize?(pioneer 115 is long open can  right?) ;D

Also if you dont feel like using 6AA batteries, you could use two or 3 rechargeable cr123a's which usually come off the charger at 4.2v each. You can get them with a charger on dealextreme for under $20.

 

[vincenthooi]

unfortunately, online ordering is out of the question. my parents is unwilling to try using their credit card online.
i had to scavenge all parts around my hometown.

 

[GooeyGus]

You should be able to find those batteries locally at any camera shop. They'll just be more expencive. Probably $12 for a pair of cr123a's

ORR... do you have a bank account? You can always sign up for paypal and use your bank account to pay for things online without having to have a card. Just an idea

 

[chido]

unfortunately, online ordering is out of the question. my parents is unwilling to try using their credit card online.
i had to scavenge all parts around my hometown.

That's going to be a problem, how do you plan on getting aixiz modules then?
If you can't get them then you're going to have to make a collimator/heatsink for the laser diode which will be kind of complicated.

 

[vincenthooi]

luckily, i already got an aiixiz module.