DX 200

IgorT said:

[quote author=goldfingerfif link=1203381562/30#30 date=1204131867]I am at work in those pics so NO smoke or fog.

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And the lights are on! Impressive!

Can't wait till mine gets here..[/quote]

Very impressive as far as beam visibility in comparison to the red.

I just took this pic in the shop at work!

Nice!

Those are very bright ambient light conditions, and i'm amazed, that the beam is so visible..

I can't wait to get mine..

It left Hong Kong yesturday, and i hope it gets here soon..

So I see your in the construction business! Me too, but I am a project manager for a casework (cabinet) shop. Couldn't help but to remark on the ducting and architectural drawings

Ace82 said:

So I see your in the construction business!  Me too, but I am a project manager for a casework (cabinet) shop.  Couldn't help but to remark on the ducting and architectural drawings  

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Nice I am a mechanical engineer, but also a local 73 sheet metal workers' union memeber.  I still go to school and work in the shop but most of my time I am in a cubicle on AutoCAD.  Glad to see someone else in the construction business!   I am still just an apprentice though, not a journeyman yet.

IgorT said:

Nice!

Those are very bright ambient light conditions, and i'm amazed, that the beam is so visible..

I can't wait to get mine..

It left Hong Kong yesturday, and i hope it gets here soon..

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Once mine left hong kong it was about 8 business days till it got here. It is amazing as for visibility.

goldfingerfif said:

[quote author=Ace82 link=1203381562/30#35 date=1204295418]So I see your in the construction business!  Me too, but I am a project manager for a casework (cabinet) shop.  Couldn't help but to remark on the ducting and architectural drawings  

Click to expand...

Nice I am a mechanical engineer, but also a local 73 sheet metal workers' union memeber.  I still go to school and work in the shop but most of my time I am in a cubicle on AutoCAD.  Glad to see someone else in the construction business!    I am still just an apprentice though, not a journeyman yet. [/quote]

Right on. I used to be in the carpenter's union when I worked in the shop, but I got promoted and now I'm managing projects. Well I'm sure I could make allot more $$ if I worked as an installer, those journeymen make bank and have good benefits. That's cool, my company takes care of me. But keep it up, that's an excellent path. Once you're a journeyman, you’re pretty much guaranteed work as long as you're honest and hard working, not to mention the pay and overtime! AutoCAD huh, what would the world be without it? I know the program pretty well personally. I'm still running 2k @ home.

Back on topic, being that I am not too fond of the quality of DX lasers, how is the divergence? The DX divergence has disappointed me on 80% of the lasers I bought from them. Perhaps you should take a picture of it @ 1 ft. then another @ 25ft. or measure the dot size.

how about power? How long should it take to shine on your palm for it to start stinging. my DX200 takes about 5 seconds before I can barely tell that its stinging...Granted, Im using the crappy included batteries... Im getting some energizer AAA nimh 900mAH recharagbles soone

Rechargeables often don't provide enough voltage for proper burning. They're great for general pointing and showing off to your friends, but they just don't provide enough juice to do a good job at burning things. Pick up some Energizer E2s or some Duracell PowerPix batteries if you really want to unleash the potential of your DX200.

I totally agree. I was barely able to get 95mW from the DX200 with fresh-from-the charger NiMh rechargeables. But fresh Alakalines and a cool laser will peak over 200mW for a brief time. (at about the 10-15 sec. mark and keep it up for a few seconds until it overheats and drops rapidly to below 200mW)

See a test with several types of batteries here: http://www.laserpointerforums.com/forums/YaBB.pl?num=1204695371

Cheers, CC

Well, i've taken my DX200 appart, mainly so i could focus it, and maybe even tighten the IR LD, since i noticed pressure on the PCB makes it mode hop.

The "driver" PCB is directly soldered to the legs of the LD. There is also a spring pushing up, against the enclosure for electrical contact. These LDs have + at the base of the body.. This spring, combined with pressure on the button push the PCB down and bend it. Not to mention putting strain on the IR LD's sensitive legs..

Simply supporting the PCB by putting a 2mm thick piece of plastic under the big transistor on the lower side of the PCB helped A LOT with stability. Before it was continuously abruptly changing brightness, now it's much more stable.


The lense is in a brass nut, which is glued in place, but can be adjusted. Unfortunatelly, i didn't have any luck making the dot smaller.. I don't know why. I could only make it bigger..


Now, that the laser is taken appart, i'm seriously thinking about replacing the PCB with a real driver board. A simple 317 with two 14400 Li-Pos would provide a much more constant output power, over most of the battery capacity. The original "driver" PCB doesn't really do anything at all. The same could be achieved with a simple resistor, even tho there are enough components on it to regulate the power through the PD feedback.

Looks like it's the same with all of these green DX lasers. I really don't understand, why they don't actually use the components on the board. But in all of these, the current is directly proportional to the battery voltage.


The laser is very hard to take appart, without damaging the silver paint on the head. I'm gonna have to repaint mine. But i did change it in a way, that it will be easier to take appart in the future.


Oh, and there are many brass splinters and lots of glue residue inside.


Also, the first lense, directly on top of the crystals is held up around 2mm above the aperture with four blobs of glue. On DX, where there is a pic of this laser taken appart, this same lense is touching the module, but with mine it's slightly above..


I'm gonna make some measurements of the PCB now, so that i can make a driver of the same size and i'll put it in when i'm done.

Oh, after i told DX about the problems with my laser, they contacted me directly, and offered to test the next one before shipping it.


I got a SKYPE address, i'm supposed to call, so i can tell them what to do directly. At least their customer support is great.

How wide does the IR component of the beam usually spread in such a cheap laser ? In terms of diameter (spot width) over distance, say at 1, 10 and 100 m ?

Is there only a direct beam IR component of the same basic shape as the green component only (much ?) wider or are there also other types of IR leakage ?

I did some testing of my DX200, which i have taken appart.

This laser is built like this:
IR pump diode -> crystal assembly -> expander lens -> collimator lens -> narrow aperture at the top.

Unlike some quality lasers there is no collimator or fast axis lense between the IR diode and the crystals, so the IR spreads, while the green beam comes out of the crystals quite narrow.
After the crystals, the small expander lens in a brass nut mostly expands the green, and a part of the IR, while the brass nut blocks most of the IR.
The collimator again mostly collimates just the green, a little bit of remaining IR, while it blocks even more of it.
The narrow aperture at the top blocks even more IR.


When i observed the beam at these various points, the IR glow around the green beam became less and less powerfull at each next component.

At the crystals there is a lot of IR glow, at the expander, there is slightly less, at the collimator even less, and at the top, it is not noticable anymore, with an unmodified camera.

So the way these are bult prevents most of the IR from coming out.
Some of it still comes out, and spreads, but it is very little - comparable to one or two IR LEDs max..


I also noticed, that if the crystals are not properly aligned, there is MUCH more IR leaking. The IR glow was MUCH more powerfull on the camera, but again dropped at each component, and at the top it was completelly obscured by the green, and not noticable anymore.


I have to wait for the laser power meter, before i can finish rebuilding my DX200 and fine-tune it, so i will repeat this experiment in front of the meter with filters, to measure the exact power of the IR at each of the above mentioned steps.


Some people have measured the green and IR output of the laser, and the IR was only around 30mW if i remember correctly.


So the main thing to worry about is not hitting your eyes with the green beam, as it is more dangerous. Even just looking at the spot on the wall from a few meters away can hurt your eyes and i wouldn't recommend it.

Has anyone actually done a spectral analysis on these to find out how much of what is coming out?

I got my DX200 today. I went into the clean room at work, and at 16% humidity, it lost ALOT of power at 20 feet. Can't burn paper when I tried. Up close it was ok. I suspect then that most of the burning power is IR, and it is spreading. The 532nm dot didn't change in intensity any, and is colimated ok for a cheap laser.