Diy Red Help

[dmartin]

First of all, first post, love the site.

I wanted to do this, diy laser, for a while after I saw that silly maglite mod video. Well yesterday I killed 4 laser diodes due to absolutely no mention that you are sending your diodes to led hell with the maglite mod. "huh why is it dim?", is something I asked my self often.

I then read up on what I need to do here.
I' ve killed another 4 diodes today twice due to soldering (any tips, its a pain in the ass), and twice because i looked at the open can funny (no really then i dropped them opps). I had a good lot of old dvd burner, garage sale all 8 20 bucks.

After my nice story comes the questions.
I have had a diy red operational, my circuit is a resistor 5 ohm, a 100uf 35v cap, and a silicone diode, and a LD, powered off 3 AAA batteries in my LED flash light.

Q1) is this enough protection, I would love to use DDL driver but it wont fit. With my circuit I was running it off the breadboard for about, above 200mA, 2 min then it got kinda warm and it seemed fine.
Q2) how do i calculate the approximate mA, that my diode is pulling? I can test up to 200mA on my DMM, but i might get reading of 170 when I'm expecting 225ish.
Q3) I couldn't seem to get my laser focused properly. It was either a longrange pointer or a closeup nuke, is this the way it is or should i try something else?

thanks a lot,
dm

 

[SargeMX5]

Some people have ran them by just wiring a resistor to the +ve on the diode and then using 2aa or aaa batteries(rechargeables)

 

[paper183]

Did you have an aixiz or dx module to put the diode in ? from your post it seems like you did but it's just to make sure.

 

[dmartin]

for my module, i dissembled a radioshack laser pointer and I am using its lense.

dm

 

[roSSco]

What is the diode mounted in? It needs to be in something to wick away the heat!

 

[dmartin]

Im sorry, I wasn't clear. I mounted the laser diode in the one i got out of my radioshack laser. I think it works fine, at something > 200mA it ran for a minute and it was only mildly warm. I can add a large heatsink, and may end up doing so to make it fit in my case.

 

[dmartin]

Well I went to my local radioshack and picked up a few things, a soldering iron, a new DMM that can go up to 400ma (my last one has died or something, can't give me mA ratings only zero, and it wont read voltages or ohm reliably ), and im going to mount this in a project box so i can put ddl full driver in their.

 

[paper183]

if you can take picture of how you assembled everything, maybe we could help a little more.

 

[Hemlock_Mike]

DM --
1:  You may have blown the fuse in your DMM if you didn't connect it right.
2:  The RatShack laser may not be a good enough heat sink.  Brass or Aluminum ??  Did it press fit ?
3: I can't teach soldering from here.  It's an art but easy if you have the equipment.
4: Were those DVD's all the same?? Older ones are low power.
Mike

 

[wooooooolazer]

It doesnt matter if it can only go to 400ma what matters is the voltage, to effectifly measure the voltage going to it you need to put a 1 ohm resistor in series then set the meter to volts and measure in series on the resistor to figure out the ma it is drawing.

...lazer.. ;D ;D ;D

 

[dmartin]

Ok, sorry forget any questions about the circuit, I have a DDL Driver up and working, along with another circuit to step a 9v down to 6.25 (working to get to 6, im 20ohms off)

the heat sink for the radioshack:
brass for where the laser diode sits,
brass for what holds the lens, and
aluminum for a larger enclosure housing. with a few trials it didn't get warm after a minute which i wont ever run for longer.

right now im running 127ma for the diode and will change it to 200-250ish,
but you are telling me that the setting for my DMM is inaccurate? i must investigate!

for my trial boxes of dvd, all pioneer 18x burners. about a year old. no idea why they were selling and didn't care.

 

[wooooooolazer]

woah!! 8 18x dvd burners for that..man!! that is a massive steal, you got lucky....

Ill post a pic how to measure current in a little, got to draw it in paint.

...lazer... ;D ;D ;D

 

[Switch]

woah!! 8 18x dvd burners for that..man!! that is a massive steal, you got lucky....

Ill post a pic how to measure current in a little, got to draw it in paint.

...lazer... ;D ;D ;D

Got really lucky and then turned all his luck into a bunch of LEDs :'(

 

[dmartin]

Got really lucky and then turned all his luck into a bunch of LEDs :'(

I was quite sad too. If it weren't for that stupid maglite hack video I wouldn't have wasted all those diodes, (well i learned a lot)

Anyways good news its done and it works. Still haven't got the focusing right but its better and at the moment i really don't care. I can burn crap at about a foot, after that its too big. I'll get it working on my hd-dvd diode. ;D (well i figured hd-dvd is dead now that only one major distributer is on board). I got a hd dvd attachment for my 360 for christmas and now i got a blue violet diode.

i guess i figured out my problems, but thanks for the great site.

 

[paper183]

If you want to focus as you like you should really get an aixiz module or the like. because you probably cannot adjust the focus on the radioshack pointer.