DX200 FIXED!!!

Goldfinger.. Did your beam just split, or was it changing in brightness as well?

Did you by any chance measure the current on Ni-MHs or alkalines?


I think i just found a current, where it remains in TEM00!! Need to do more testing, but it looks promising.

Ok, i did some more testing, and the results were kinda surprising..

On fresh Duracell alkalines, the beam splits in two almost immediatelly, and the current starts at above 550mA and is constantly dropping (since their voltage drops constantly).. When it drops below 500mA the beams come back together and the spot becomes brighter.. Once the batteries are slightly discharged, the current starts below 500mA, and even when it falls down to 450mA the beams don't join back together anymore..


On fresh Varta 1000mAh Ni-MHs, the current starts at 440mA. The beams split immediatelly, just like before. But unlike with alkalines, the current doesn't start dropping.. On Ni-MHs the current is actually slowly climbing!

I watched it slowly climb to 450mA, and when it got over 450mA, the two beams joined into one, and the spot became much brighter..


I was surprised to see the current climbing at first, since i only saw it drop on alkalines.. I did expect the current to slowly climb on a PSU. But Ni-MHs keep the voltage steady for much longer, than alkalines, and as the IR diode inside heats up, it's resistance decreases, and allows more current to flow through..


It's not as bad as i thought at first.. It looks like mine just has some special, slightly different needs..


Since i was thinking about modding it, before i even got it, i'm gonna try running it off a current regulated supply. If it helps, i'm gonna put it in another host with my own driver...

IgorT said:

[quote author=r34p3rex link=1204416398/0#13 date=1204700654]i charged the ni-mh for about 6 hours and they reached 1.4 volts (thought i killed them x.x) but turns out, works great just as goldfinger promised no more TEM01 after a few seconds ALL HAIL NI-MH!

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Oh, so you also have the DX200? You guys are lucky....


Mine just got here, and at first i thought it even works great, even on the included alkalines, but i did notice it spliting into two parallel beams.


So i put in my Ni-MHs, but it wouldn't help much...


After only a few tries, it starts mode hopping almost instantly. First it splits in two beams, one of them brighter, then the brighter one dims, and it looks pathetic.... Sometimes it starts jumping between bright and dim and almost "blinks"...

When it's dim, the beam is still more visible, than a <200mW red, but the spot looks the same brightness..



I tried two different Ni-MH types, but nothing helps. What capacity Ni-MHs are you two using?

I guess i really am going to have to return mine...[/quote]

DX True 30

Well, the problem is definatelly overheating..


If i put it in my small cooler for a few minutes, the beam is perfect, and never splits.. At least now i know what to do, to fix it...

r34p3rex said:

DX True 30

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I see.. So the DX "True" lasers also mode hop.. Well, at least it means i'm not as unlucky as i thought.

I just got my DX200, I dont seem to have the mode hopping problem, but I do seem to have a really bad divergence factor. I can actually tell the beam is spreading as I shoot it across the room (about 20 ft)

Is it normal to be this bad? I dont have my glasses yet, so I havent tried the balloon pop or match light trick.

BTW, where would be a good place to buy an IR filter that appropriately fits this DX200? do I just yank that fron silver tip end off?

BTW2, is there anyone on the board in Atlanta GA that could do a power measure for me?

opticalc said:

I just got my DX200, I dont seem to have the mode hopping problem, but I do seem to have a really bad divergence factor.  I can actually tell the beam is spreading as I shoot it across the room (about 20 ft)

Is it normal to be this bad?  I dont have my glasses yet, so I havent tried the balloon pop or match light trick.

BTW, where would be a good place to buy an IR filter that appropriately fits this DX200?  do I just yank that fron silver tip end off?

BTW2, is there anyone on the board in Atlanta GA that could do a power measure for me?

Click to expand...

nova lasers sells a small IR filter that should work great with your DX 200.. you may want to just mount it externally because mounting it internally would be a big hassle

opticalc said:

I just got my DX200, I dont seem to have the mode hopping problem, but I do seem to have a really bad divergence factor.  I can actually tell the beam is spreading as I shoot it across the room (about 20 ft)
Is it normal to be this bad?  I dont have my glasses yet, so I havent tried the balloon pop or match light trick.

Click to expand...

Unfortunatelly it is quite usual for it to be like that. The one i just got today is the same..

This also means, it won't light matches and probably won't pop baloons, because the power is spread over a larger area...


BTW: If you look at the beam from the side and rotate the laser, is the beam the same width from all sides? If it's wider from one side, it means it's splitting.. Sometimes it can take a while before it does this. When it does, the beams slowly slide appart.. In the beginning they can still look like one beam, only wider, then they can separate completely. I discovered mine does work a little better from Ni-MHs, and it helps A LOT, if it's cold..


If you could check this, i would be very greatefull, as it seems i have to order another one.. If the beam is the same thickness from all sides, when looking at it from 90° close to the opening, and remains this way all the time, you got a good one..

Are you using the included alkalines?

BTW, where would be a good place to buy an IR filter that appropriately fits this DX200?  do I just yank that fron silver tip end off?

Click to expand...

I really wouldn't recommend trying putting a filter in there..  Well, there is a lense above the crystals, but  you need to be very sure of your abilities to attempt something like that..

As far as i heard it's also very hard to take appart..



BTW: If your laser should start varying in brightness abruptly, it's probably just a dirty switch.. Mine did this, and i thought it was completelly broken, but then i took the batteries out, and kept pressing the button for a while, so it would get a better contact.

IgorT said:

BTW: If you look at the beam from the side and rotate the laser, is the beam the same width from all sides? If it's wider from one side, it means it's splitting.. Sometimes it can take a while before it does this. When it does, the beams slowly slide appart.. In the beginning they can still look like one beam, only wider, then they can separate completely. I discovered mine does work a little better from Ni-MHs, and it helps A LOT, if it's cold..


If you could check this, i would be very greatefull, as it seems i have to order another one.. If the beam is the same thickness from all sides, when looking at it from 90° close to the opening, and remains this way all the time, you got a good one..

Are you using the included alkalines?

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I'll work on examining mine like you say when my glasses come in. I've not done too much with it except shine it across the room for fear of reflected light. Yes, I'm using the included alkalines. I'll try to see what some quality camera AAA's will do.

opticalc said:

I'll work on examining mine like you say when my glasses come in.  I've not done too much with it except shine it across the room for fear of reflected light.  Yes, I'm using the included alkalines.  I'll try to see what some quality camera AAA's will do.

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If you look at the reflection of the beam - the spot a few meters away, it is actually much worse, than just observing a beam at a larger than 90° angle, with the laser pointing away from you.

Wait, i'll make a pic of what i mean... If you point it away just enough not to see the opening, i don't think any IR can come into your eyes. In any case, MUCH less, than if you shine it at a wall. I would really recommend against doing that inside from up close without glasses.. Even the spot on a wall 10 meters away can be blinding. Never mind trying to burn something.. What kind of glasses to get is another problem. Glasses for green lasers won't stop IR. Glasses for IR won't stop green (as i'm sure you know). I'm gonna take an IR filter from my webcam and put it on my DX200. Maybe even in it.


About the mode hopping pics:
In the picture on the left, you can see the laser from above, and the two beams overlap, so they look like one.
In the picture on the right, you can see the laser from the side, and the beam splitting is very obvious. The beam should look like in the left pic from all sides. Even if it still looks like one beam, but wider from one side, it is already mode hopping.



BTW, i actually fixed mine! I'll describe how in the next post, it might come in handy.. There is a major design flaw in these, and i patched it up a bit. I already described the fix on another thread, thinking it is this one.

It is reply #20 in this thread: http://www.laserpointerforums.com/forums/YaBB.pl?num=1204695371/15