New 200mw green Kaidomain laser.(takes cr2)

[IgorT]

Nice! Almost 0.6W peak!

 

[IgorT]

Ok, i just took five minutes off work, and i took the laser appart..

I noticed before, that the driver is identical. Well, the module is identical as well. I think it's the same thing as a DX200 but in a different body. One could easily swap the modules between them, as well as with a KD50, which i think is a copy of this design.

The head IS massive aluminum. The module has an extension tube, and there is no usual "air-heatsink" between the module and the head.. But they are also not making good contact..

The most contact comes from the brass ring with the four slits, holding the module into the head (again, similar to the KD50, but actually working - at least mechanically).

This ring hugs the module just around the diode. So i put some thermal grease in it, and put it back together. I could smear some grease on the modle itself as well, so it would make full contact with the head.


I'm going to let it run in front of my meter for a few minutes again.. But it doesn't seem to help - just dropped to 42mW.... Could be the battery. Otherwise, it is now even worse than before, in which case the power might start climbing as it heats up...


BTW, in this laser, the current regulation would seem to be working! I am getting the same currents with the primary, the 3V rechargable AND with a 3.6V rechargable.
There is a little jumping up and down, but it's the same with any of the three batteries.

The power is slowly climbing now.. The manufacturers leave these improperly heatsinked, so that the crystals would reach full efficiency sooner and peak higher, even tho it also means they drop lower eventually.

But the mode hopping is gone, and the power climbed to 70mW and still climbing as the entire body is getting hot.


Hmm...

 

[IgorT]

I just noticed, that when it's mode hopping, one of the beams grazes the aperture.

But if i turn it off and on again, the mode hopping is sometimes gone. Looks like i made it a bit worse by improving the heatsinking.

I am very surprised, that the current would seem to be regulated in this unit. And if i put the same 3.6V battery in my KDX200 laser, the current is also 780mA. It would seem these lasers are set to operate at this current. But some can do it from a lower volage, and others can't...

Probably from tiny differences in components.

 

[Benm]

That's likely, since the battery voltage doesnt leave much room for regulation... i'm guessing they are using components outside specification (under-volted opamps, regulators with lower voltage drop than specified and such approaches) which may or may not work.

 

[IgorT]

Yeah, before i thought i was overdriving my DX200 modules on 3.6V, but they would seem to stop at 780mA...

Now i finally saw one, that can do it from three completely different batteries. Obviously they are set to this current. This finally gives me an idea how far i can go with these diodes... I was wondering about the current for a long time now.

I'm not sure it will be an improvement tho. There would not seem to be much difference from 650-680 up anyway. It can even get worse in fact..

 

[IgorT]

I managed to get it to stop mode hopping somehow.. No idea how. I took it appart a couple of times, put it into a different body and back again, removed the heatsinking paste....

Now it's quite stable actually. Not in power, but in transverse mode. The power peaks at just above 120mW and again it spends most of the time betweeb 80-90mW. Unfortunately it drops to 55 eventually..


I really thing i should return it, just because i'm angry with KD. They promised they would test it like i asked.

 

[Razako]

I managed to get it to stop mode hopping somehow.. No idea how. I took it appart a couple of times, put it into a different body and back again, removed the heatsinking paste....

Now it's quite stable actually. Not in power, but in transverse mode. The power peaks at just above 120mW and again it spends most of the time betweeb 80-90mW. Unfortunately it drops to 55 eventually..


I really thing i should return it, just because i'm angry with KD. They promised they would test it like i asked.

They probably did test it and it got knocked out of alignment during shipping.

 

[thejunkmonger]

[quote author=IgorT link=1208565145/48#53 date=1211673354]I managed to get it to stop mode hopping somehow.. No idea how. I took it appart a couple of times, put it into a different body and back again, removed the heatsinking paste....

Now it's quite stable actually. Not in power, but in transverse mode. The power peaks at just above 120mW and again it spends most of the time betweeb 80-90mW. Unfortunately it drops to 55 eventually..


I really thing i should return it, just because i'm angry with KD. They promised they would test it like i asked.

They probably did test it and it got knocked out of alignment during shipping.[/quote]

And you believe in Santa Clause

 

[Razako]

[quote author=Razako link=1208565145/48#54 date=1211731590][quote author=IgorT link=1208565145/48#53 date=1211673354]I managed to get it to stop mode hopping somehow.. No idea how. I took it appart a couple of times, put it into a different body and back again, removed the heatsinking paste....

Now it's quite stable actually. Not in power, but in transverse mode. The power peaks at just above 120mW and again it spends most of the time betweeb 80-90mW. Unfortunately it drops to 55 eventually..


I really thing i should return it, just because i'm angry with KD. They promised they would test it like i asked.

They probably did test it and it got knocked out of alignment during shipping.[/quote]

And you believe in Santa Clause[/quote]
I'm just saying that even a well tested laser can arrive at your door in poor condition. My laserglow vega arrived with the collimating plate completely knocked out of place and the laser diverged like a flashlight. I had to open the head of the laser and and readjust it myself.

 

[IgorT]

Well.. Had i known up front this is the same module as the DX200, i wouldn't have ordered it...


The one DX200, that was actually tested for me by Rain from DX is the ONLY DX200 i have seen so far, that doesn't mode hop. It is doing great in the Rominsen L-D030 body, and it's my favorite green at the moment.

Of course, even tho it was tested, it didn't work perfectly - it wouldn't work with the batteries in the tube... ;D


But it was just a contact problem, that got worse and worse every time it was put together.

I don't believe anyone from KD actually followed my testing procedure:
- 1 minute at a wall to check for abrupt brightness changes
- 30 seconds through a magnifying glass immediately afterwards to test for mode hopping


They just said they would, when i threatened i would return the bad KD50s if they didn't.....

 

[Benm]

I guess they wont do you the favours dx does. QC is probably limited to 'green light comes out' and not much beyond that. If there is a good chance of actually getting a refund i'd probably return the whole lot - saves you shippings costs on the individual items.

 

[IgorT]

I doubt they will accept the KD50s after all this time..

Besides, i'm using the parts.. But this one was $100! Green light comes out indeed.