First Attempt (fail)

My first laser experiment was a failure. I purchased a diode from Hightechdealz press fit into an axis housing. Thinking the easiest way to get started with burning laser pointers was to have all the new things pre done for me so all I would have to do was build the driver and solder things together. Maybe machine out a housing. After I spent the morning surface soldering a Rkcstr driver and setting it to 200 ma using a 10mm LED I was ready to light some matches. So I unscrewed the rear of the axis housing and soldered on the connection. To find … disappointment. My LED was way brighter then this 20x dvd burning laser diode (LOC). So I tried turning up the power to 380ma with my multimeter between the driver and the diode but again it was just not impressive.

That’s around the time I did some reading and found this forum. From what I’ve read I think the diodes toast but am not sure why or how. The output is certainly not collimated in any way (should the output be collimated?), its just like a normal LED. Also the axis housing seems to get very hot with use, it seems better suited for burning things then the light. Being that this driver cannot exceed 400 ma I have no idea what happened.

I’ll be trying again, but have no idea where I went wrong. Does anyone have any tips, or at least things to avoid? Is there something I’ve completely overlooked, IE should I be pulsing these diodes? I tried to go out of my way to make sure as much was pre done as possible, and yet…

It sounds like you've done everything right.

However, let me ask you first: did you screw a lens into the aixiz housing? Laser light from a laser diode is uncollimated, so you need to put a lens in front and adjust it so it forms a beam (or a point if you're doing burning). Your Aixiz housing should've come with a lens and spring.

Another thing to do with your lens: cut away the black plastic around the back of it. It'll allow a lot more light into your lens.

also, if you are running max current for that particular diode the aixiz will most definitely get hot. additional heat sinking is required for any kind of life.


michael.

The aixiz module did come with a lens and spring, I used both. Whats the purpose of the spring? I could focus the light into a very fine point, with a line through it.

How can I get the aixiz lens to collimate? Do I just screw the lens all the way down.

Just to recap this diode is trash right? Its not like there is a film on the lens or something right?

I'll look into the plastic when I get home, sound quick and easy.

it will indeed need to be screwed almost all the way down. so you will remove the focusing ring for first time.. then you will know where to install the focus ring.. the spring is to keep the lens stable.. if you dont like the spring you could give a couple wraps of teflon tape...

if you are sure your driver is set to the correct value for your diode and you are not lasing then your diode went led.... assuming you have your lens in and screwed in to the correct spot. it should all be very obvious, even for a beginner.

michael

Ok its toast, I'm just disappointed I couldn't even get one second of use out of it. Are DOA's common with this hobby?

If say I dropped the loaded aixiz housing on my desk when unpacking it, could that have killed the diode?

Can anyone recommend a replacement diode? Ideally something in the 200mW-300mW range, LCC, and cheap?

Hold on, did you actually measure the current with the instrument? Or did you simply adjust the driver to light up that LED?
Any normal LED would die at 100mA, let alone 200+.

Are you sure you have not powered the driver without a load? If you have, you could have gotten the output capacitor charged and as soon as you've soldered to the diode, it discharged over poor little thing.

Next, can you take a picture or two of your setup? And your soldering work? Laser diodes are very sensitive, too much heat could have killed it.

ZeroCover, my LOC is running at ~350mA and does look dim compared to a red hi-power LED. Try focusing it down to a pinpoint with the lines across it and see if the pinpoint will smolder black plastic or a wallet. Also, defocus it and see if the red light that is emitted is grainy like laser light.

if the aixis gets really really hot really really quickly, the diode's probably toast. My LOC is only in an aixis right now, and it gets a little warm after about a minute. I haven't run it long enough to get scalding hot, but it would take 2 minutes or so I'd imagine.

Eudaimonium said:

Hold on, did you actually measure the current with the instrument? Or did you simply adjust the driver to light up that LED?
Any normal LED would die at 100mA, let alone 200+.

Are you sure you have not powered the driver without a load? If you have, you could have gotten the output capacitor charged and as soon as you've soldered to the diode, it discharged over poor little thing.

Next, can you take a picture or two of your setup? And your soldering work? Laser diodes are very sensitive, too much heat could have killed it.

Click to expand...

First image is living proof that an LED can take 300+ mA, although it starts to dim, and the camera flash is way brighter.


Then a picture of the layout. Its a battery pack -> the driver -> its leads -> alligator clips + to red, - to the multimeter, multimeter to - of the driver.


the driver front

and back


focused laser


and not

Looks like it's probably dead to me, I'm afraid. Lucky it was only a cheap diode - it's only been a few years since that kind of loss would put you back $50+. Ideally, you should keep your leads as short as possible, with few quickly detachable points (if any) - if the connection is loose, it can cause the diode to be "jolted" by the capacitor on the driver, killing it. I'm not sure what killed it (hard to tell), but it is most commonly ESD (never leave any wires floating, always short the pins when not connected to anything else) or over-current. Did you discharge the capacitor on the driver before connecting it to the driver?

your last photo obviously looks red. but the othe 2 look like IR? am i the only one thinking that?

michael

charliebruce said:

Looks like it's probably dead to me, I'm afraid. Lucky it was only a cheap diode - it's only been a few years since that kind of loss would put you back $50+. Ideally, you should keep your leads as short as possible, with few quickly detachable points (if any) - if the connection is loose, it can cause the diode to be "jolted" by the capacitor on the driver, killing it. I'm not sure what killed it (hard to tell), but it is most commonly ESD (never leave any wires floating, always short the pins when not connected to anything else) or over-current. Did you discharge the capacitor on the driver before connecting it to the driver?

Click to expand...

I did not think to discharge the cap after running it with the LED, its such a small cap how much power could it possibly store (apparently too much). Also I've not shorted the pins for any reason. So it could have been ESD. Strangely enough I've never had anything die due to static, maybe I've just gotten over confident.

I never thought to run shorter leads. So it could have been the huge mess of alligator clips that did me in. Wow laser diodes are really sensitive. Is there anything I can do like put a capacitor on the diode directly to help out.

zerocover said:

I did not think to discharge the cap after running it with the LED, its such a small cap how much power could it possibly store (apparently too much). Also I've not shorted the pins for any reason. So it could have been ESD. Strangely enough I've never had anything die due to static, maybe I've just gotten over confident.

Click to expand...

Oh it is even worse with Blurays. They're even more sensitive.

I never thought to run shorter leads. So it could have been the huge mess of alligator clips that did me in. Wow laser diodes are really sensitive.

Click to expand...

Yeah, they don't always have a firm grip too, and just a momentary disconnect/reconnect can fry the diode.

Is there anything I can do like put a capacitor on the diode directly to help out.

Click to expand...

Some do that, but the capacitors can sometimes hold charge too, so that may not be what you want. It's usually enough to keep the two leads on the driver shorted (connected) until the diode is completely soldered up. I use a bare piece of wire bent back on itself (a paperclip works well) to hold the two wires shorted. Then after you've gotten the diode soldered on, unclip the wire.

Trying to adjust the power while the diode is powered can sometimes kill the diode too, as the pot may not have continuous contact. So if you didn't check the current with a dummy load, I would make sure you turn off the power before you adjust.

It has happened to all of us I'm sure.
Here is a good read.
http://laserpointerforums.com/f44/learn-mistakes-can-happen-anybody-50044.html

Your problem may have been the first example in this thread

Yup, I'll tell you the problem right away - the aligator clips !

DO NOT use those in this hobby.

YOU MUST have a very solid solder connection between diode and driver, aligator clips are anything but stable and will disconnect for few microseconds and capacitor will charge up and guess what that means.

I guess we solved it.
Your diode is dead, sorry

Solder the wires from your diode, to your driver and you will save yourself A LOT of dead diodes and frustration on the way :beer:

Take it easy, order another diode, try again. We've all been through it

Also, you might want to replace your xx AA battery pack for 3x Lithium ion (14500 is exact size of AAs, if you want to reuse the holder).
It'll give you much fun and less frustration from buying new batteries every one in a while , lithiums are rechargeable and not very restricted like NiMH are (you can charge li-ion how you like).

Possible murder

Just a long shot, but worth the try.

Ditch the DMM, get fresh batteries, have the battery and LD directly to the driver. (solder), and give it about 7v

Its also hard to tell from the photo, but is the LD + - bridged?

and resize the photos, lol