Red DIY DVD laser burner.

[Kenom]

essentially your wasting capacity in your laser. YOur driving a boost converter to a voltage regulator when all you need to do is use a limiting resistor.

 

[toked323]

well i was the easiest way to set it to 350ma usually when i set them to 250ma i use just a resistor

 

[Gazoo]

well i was the easiest way to set it to 350ma usually when i set them to 250ma i use just a resistor

Not sure which Dorcy this is, but if it's the one that takes a CR123 battery you could use a RCR123 battery and do away with the Dorcy regulator entirely.

The Dorcy Metal Gear is also a good candidate for the 7135, and would be perfect using three nimh batteries. Alkalines would work but would not last nearly as long.

 

[toked323]

yea but i like using egular c123 batts cause i sell them to my friends

 

[Maxx]

i dont want to read over 30 pages of posts, can someone tell me what else ill need to get this to work properly, i started to read into it and heard talk of the need of capacitors, but thats not in the the steps described in the first post. i need some help. or is it that the curent stuff on the mini dorcy's board is fine for my laser

 

[Kenom]

there are capacitors on the board inside the dorcy.  additional capacitors are not necessary. As far as parts needed you need

5 ohm resistor 1/4 watt or less or a 3.3 ohm resistor if you really wanna driver it hard.

 

[Maxx]

how hard is driving it hard

 

[Hellcat]

Well I mounted four 10 Ohm resistors and compared them to my other one with three 10 Ohm resistors and the difference as far as I can see (beam length in the fog) is not much. In terms of burning, the one with four resistors does pop balloons faster, but still takes awhile unlike the vids I've seen on these forums. Also it still does not light matches I cut out the lenses too. I know I did everything right. Could it be the LD's themselves? It the groupbuy diode from Senkat Overall, I am still pretty please with it's lasing and the fact that it's as bright as my 5mW greenie in the fog. We had a lightsaber battle in the fog on Boxingday! I wish I had a camera set up!

 

[flogged]

Well I mounted four 10 Ohm resistors and compared them to my other one with three 10 Ohm resistors and the difference as far as I can see (beam length in the fog) is not much. In terms of burning, the one with four resistors does pop balloons faster, but still takes awhile unlike the vids I've seen on these forums. Also it still does not light matches I cut out the lenses too. I know I did everything right. Could it be the LD's themselves? It the groupbuy diode from Senkat Overall, I am still pretty please with it's lasing and the fact that it's as bright as my 5mW greenie in the fog. We had a lightsaber battle in the fog on Boxingday! I wish I had a camera set up!

Ug, OK.. first off unless you actually meter the current the driver is using you're just shooting in the dark.

You're using way less than 5 ohm resistance (not recommended) and you should be dumping loads of current through the diode.

Half the equation for a burning laser is the optics/divergence!! You can have a really powerful laser but if you can't get a tight focus it aint gonna burn shit. The raw output from the LD needs to be properly collimated. Another thing is if you have the focus set for infinity you're not going to be able to burn things up close. To light matches, burn electrical tape, etc. the focus needs to be close. You really want a a housing that lets you adjust the focus of the lens.

You can practice learning what a tight focus looks like, say at infinity. Try to adjust the focus so the spot is as small as possible 25 feet away. You may need to use shades to evaluate the spot size In my DIY the spot is tiny a 25 feet, just a few mm on a side. And for up close burning I can focus the spot down to a speck.

ANyway, my first DIY red I used TWO 10 ohm resistors (5 ohm resistance, 225 mA current draw) and I could pop balloon to over 40 feet, light safety matches out to six feet.. etc. But that was likely because I was using the decent Meredith focusable lens assembly which uses a fast acrylic lens.

 

[Maxx]

what would be the best amount of ma's that i should use for my laser, from reading back a couple of pages, i have seen different amounts. and whatever you sugjest, what would be the right resistor for it?

i am not so savy when i comes to electronics (as you could probably could tell) ;D but i want to get better, so if there are problems with what is said (like wording). please tell me

 

[Dark_Horse]

I have just finished my first DIY-Dorcy JR burning laser ;D. I used Kenoms method mostly, but instead of the "lense-cover" cut from plastic, I machined a CPU heatsink with a "pocket" for the Axixis housing to nest into,(with Arctic-Silver on all contact surfaces), and machined the heatsink round to the inside-diameter of the Dorcy JR. I then connected the doide to the power with wires, (although next time I would just use the leads, like Kenom). This worked really good, disipates heat very well, looks really cool, and perfectely centers and aligns the diode in the Dorcy head, looks like it was made that way.
I do have a couple of important questions though:
(1) My voltage measured 5Volts to the diode-pads, prior to mounting the LD, isn't it supposed to be about 3 volts?
(2) What resitors? The walkthrough and video do not mention modifying the Dorcy circuit, other than removing the LED and isolating the +and- contacts, does it? I did not add any resitors at all.
The laser works really well, lights unsharpied matches almost instantly at 6" focus, pops ballons instantly at 6" focus, etc, does everything it is supposed to.
Am I allowing too much ma's to the LD? am I going to burn it up quick"
I would hate to kill my shiny new "Death-Ray" in a couple of hours, especially when it seams to be working perfect.
I am weak on the electronics, any help?
Can anyone help with the resitor/ma/possible overdriving question, (same as questioned above)

 

[roSSco]

I have just finished my first DIY-Dorcy JR burning laser ;D. I used Kenoms method mostly, but instead of the "lense-cover" cut from plastic, I machined a CPU heatsink with a "pocket" for the Axixis housing to nest into,(with Arctic-Silver on all contact surfaces), and machined the heatsink round to the inside-diameter of the Dorcy JR. I then connected the doide to the power with wires, (although next time I would just use the leads, like Kenom). This worked really good, disipates heat very well, looks really cool, and perfectely centers and aligns the diode in the Dorcy head, looks like it was made that way.
I do have a couple of important questions though:
(1) My voltage measured 5Volts to the diode-pads, prior to mounting the LD, isn't it supposed to be about 3 volts?
(2) What resitors? The walkthrough and video do not mention modifying the Dorcy circuit, other than removing the LED and isolating the +and- contacts, does it? I did not add any resitors at all.
The laser works really well, lights unsharpied matches almost instantly at 6" focus, pops ballons instantly at 6" focus, etc, does everything it is supposed to.
Am I allowing too much ma's to the LD? am I going to burn it up quick"
I would hate to kill my shiny new "Death-Ray" in a couple of hours, especially when it seams to be working perfect.
I am weak on the electronics, any help?
Can anyone help with the resitor/ma/possible overdriving question, (same as questioned above)

What kind of LD are you using?

 

[Dark_Horse]

I purchaesd the GB Sony Diode-preinstalled in the Axixis housing and the Dorcy Jr, all from Senkat's page-(StoneTec Electronics). By the way, thank you soooo much Senkat for making these parts available, and to Kenom for all of this great information, talk about one stop shopping.
Since posting my original questions, I have reread the earlier posts, they make much more sense having actually built one now. It seams like the Dorcy has the needed cap's, and there seams to be different opinions as to weather the resitors are neccassary or not, I guess I will just see how long the diode lasts, if it is short, the next diode will likley get some resistors. My heatsink, axixis holder should help significantly with the heat problem.
I have not taken a ma reading yet, (not quite sure how either). I did buy a "7-function" multimeter from Harbor-Frieght, I am thinking I plug the probe into the DCMA hole, (instead of the VDC hole), and take a reading from the +and- of the LD, while in operation?
I cannot say it enough, thank you so much to everyone!!!,
Dark Horse

 

[roSSco]

The reason I asked is that the 20x open cans work fine @ ~300mA, no resistors.

 

[Dark_Horse]

So if I toast my 16x canned diode, sounds like I will have to, get to upgrade to a open can, Silver-lining? :
BTW, I understand the voltage thing now too, over 5volt when "open circuit" but drops to 3volt under actual operation. Sorry for asking old questions. Still not sure if I am going to add resistors yet though, or even where they would go, (in series on the positive side of the LD?)

Dark Horse

 

[Gazoo]

You should google for information on how to use a DMM. The probes go in series with the diode, it can be on the negative or positive side. If you do this make sure you have good connections or you will get a 5 volt spike into your diode and kill it.

I think you are OK. I get a reading of 2.96 volts on my SenKat diode, and I am driving it with 250ma's.