New DX Green MODULES

[seoguy]

4V???

4.5V???

Awwwwwk!

(sometimes when I'm reading LPF, I feel like this poor fella!)

Even after RA_pierce and disma repeatedly warned about keeping the voltage down...

It's possible that the driver does not regulate voltage very well and the over-voltage killed the diode. If this is the case, these may not be able to be run on rechargeable lithium battery types at all without significant risk to the diode.

Then after he burned his out...

I would recommend to anyone purchasing these:

Watch the amount of voltage you pump into these

And Disma, even after he turned his pot down BELOW normal operating level (to only 450ma)...

I tried turning the voltage up some more and the board started to get really hot at about 3.3v, I was trying to get it up enough to put the module into an 18650 host, so unless you add some voltage drop diodes or some other voltage limiting part in series with the 18650, it wouldnt be safe to do this.

You don't know how frustrating it is :banghead:, after many of us "early adopters" got defective units :cryyy: (DOA, contaminated, mis-aligned, 5 minute life expectancy), to see when a few ppl get LUCKY enough to get some decent ones, that the first thing they want to do...

is torture them to death!

Now, I know there are cases when the drop-out voltage of the regulator is such that there is not enough voltage left-over to drive the laser to full power, so increasing the input voltage a LITTLE bit can help things.

This is NOT one of those cases!

I took a closer look at that driver. Power for the laser diode appears to be pulled directly off of the batteries, controlled via a driver transistor and a 0.33 ohm resistor in series.

I looked-up the specs on that driver transistor. It has a C-E voltage drop at saturation of typically only 0.3V. Assuming a typical operating forward voltage on the IR LD of 2.2V, and with that 0.33 resistor, even with an input voltage of only 3V, this circuit should still be capable of delivering over 1.5A to the LD!

Now, consider what happens when you feed this circuit 4.5V. The LD is now using less than 1/2 of the voltage, over half of the power you are feeding it now has to be dissipated by those two components!

the board started to get really hot

That big resistor gets hot as he'll

Gee, I wonder why? :thinking:

I don't know about you guys, but my driver didn't come with a 10W resistor!

IMHO, putting that much voltage into this design is pushing both of those components WELL beyond their maximum ratings! :tsk: This is particularly true, given that that driver transistor does not have any heat sinking attached, not even a PCB trace one!

Before you destroy any of these new modules from over-voltage...

Too late! -

Killed one at 4.3V.

Before you destroy any MORE of these new modules from over-voltage...

Could you please try checking the current draw & LPM output of these modules at their rated voltage, so that we can get an idea of what they are actually set to by the factory?

When you over-stress the driver to the point it's malfunctioning, the #'s become much less meaningful!

I also wanted to post this warning, lest newbies copy what some of you are doing, and then wonder why their new laser started their house on fire! LOL

I understand the desire to get as much power as you can. But given that this driver may be capable of driving a 500mw IR LD to destruction even at the rated voltage, might I suggest that, rather than pumping too much voltage into these and seeing which component you can burn-out first , it might be more advantageous to adjust the setting on the driver to increase the current to the LD?

Of course, if you're more interested in creating a space heater, or an incendiary device, then more voltage is way to go with these! LOL!

BTW, I was able to run some further "live fire" tests & measurements on my new 100mw module, and will post results on that here shortly! :yh:

 

[seoguy]

All units are functional and have a very bright beam, with a sharp dot. Tried a 30 mW unit with two AA batteries...

So I tried again, this time with a simple CR2 and success! The module works flawlessly and according to my tester, draws 136/137 mA. Picture below:

roddenberry, good job, and great pics! :gj:

The exterior casing and driver both appear identical to my 100mw one!

Can you get a picture from the back showing where the pins go into the diode?

Also, if you could carefully unscrew the base portion of the brass module on one of them, and get a pic of the crystals / front of the diode? (With the power turned OFF, of course!)

I want to see what size/kind of diode they are using in yours, also if they are using the same crystals as are in the high-power modules!

Were all three of your modules 30mw ones? Have you had a chance to test the current draw on the other two yet? DO you have access to an LPM, to check beam power?

I don't know about the lower power modules but the 200mW I received has a 9mm pump.

My 100mw also appears to be 9mm. From the pin spacing, it is noticeably bigger than the diode on my O-Like 40-50mw module.

did anyone ordered/received 50 or 100mw version of these DX modules?

alx, yes - I have a 100mw.

if yes, what IR diode inside: 5.6mm or still 9mm (like on 200mw version)?

As indicated above, mine has a 9mm LD. In fact, I think that it may be exactly the same as the 200mw! (Just not over-driven!)

but on 100mw is possible to be 9mm (TO-5) IR diode (0.5w or 1w).

At the moment, some of us suspect 500mw 808's for both the 100mw & 200mw units (with the 200mw units being over-driven). Current measurements of both units at the proper voltage should get us a better idea on that.

If my guess is true regarding 100mw version, we have a chance to have better crystals inside and/or an IR diode capable to output over 0.5w (normally 0.5w is the limit for cheap crystals with 100-125mw output).

Actually, we were able to track-down crystals that appeared identical in apearance & size to those in my 100mw unit, and which were claimed by the seller to be capable of up to 200mw. I'm not certain, but from what RA_pierce indicated, I believe the crystals in his 200mw unit were identical to mine. See my post #79 for more info & pics on this topic.

However, a 1W IR diode at full power, would be too much for these crystals to handle. That is one of the reasons we believe even the 200mw modules may be running (severely over-driven) 500mw diodes!

can someone compare crystals inside 200mw module with the one in low powered modules (5, 10, 20, 30, 50mw)

That's the reason I asked roddenberry to take those pics.

or true 5mw pen

I'm trying, but I seem to have a newer model, and while I've managed to put enough force on it to badly mangle the aperture cap and actually tweak the case, I've YET to get the damn thing apart!

 

[Benm]

Hehe.. thats one rant up there - take it easy

You're absolutely right about the power dissipation in the driver though. If the driver was constructed properly, it would draw the same amount of current at 3.0 or 4.0 volts, and increasing the voltage should not make the laser any brighter. I am not sure this is the case here.

It might be possible to heatsink the transistor (or fet) to some degree. The resistor is less likely to be a problem, mainly because those usually survive high temperature operation very well - i've seen them desolder themselves from a circuit board, and they still worked afterwards.

If the driver is constructed well and takes the same current at 3.0 or 4.0 volts, i'd recommend inserting a (1n400x or so) diode in series with a lithium battery to drop the voltage by roughly 0.7v, back in the safe area.

 

[roddenberry]

roddenberry, good job, and great pics! :gj:

The exterior casing and driver both appear identical to my 100mw one!

Can you get a picture from the back showing where the pins go into the diode?

Also, if you could carefully unscrew the base portion of the brass module on one of them, and get a pic of the crystals / front of the diode? (With the power turned OFF, of course!)

I want to see what size/kind of diode they are using in yours, also if they are using the same crystals as are in the high-power modules!

Were all three of your modules 30mw ones? Have you had a chance to test the current draw on the other two yet? DO you have access to an LPM, to check beam power?

Thanks.

Right now, i'm right in the middle of an event i'm organizing and will be away from my lab until next Monday.

But i'll certainly try to provide the images you request as soon as I can. I did unscrew the module and saw the crystal that's glued to the 3/4 brass slug. It is absolutely minuscule, i'll take pictures of that too.

I have one 30 mW and two 20 mw units, haven't thested the current draw for neither of the two 20 mW units. I do not have an LPM, but i've been thinking about looking into one of LaserBee's LPM DMM probes.

Robert

 

[RA_pierce]

I did some more investigation on my dead 200mW module...
It appears that the diode was slammed with enough current/voltage to obliterate the tiny wires connecting the die to the pins.

Also, When I removed the crystals, there was some sort of sticky adhesive all over the surface of the heat sink which got all over the crystal facet... this module is not worth working on. I'm just calling it $47 of junk parts.
If anything, I'll just get a new one and be careful with it.

 

[alx]

The exterior casing and driver both appear identical to my 100mw one!

Right to the point! That was my guess too... 100mw and 200mw modules are different just by current driving (probably the same) TO-5 IR diode.

Were all three of your modules 30mw ones? Have you had a chance to test the current draw on the other two yet? DO you have access to an LPM, to check beam power?

That is my intention. I ordered few low powered modules and one 200 mw module. Probably I'll receive it next month. I have all required equipment and I am planning some extensive tests and also some module case modification.

On my tests, I will remove the original driver and power modules on my regulated power bench supply (0-30V/0-3A) fixing the voltage at 2V (or even less - 1.5v). This method should give us a better picture regarding IR diodes and crystals inside and eliminate other problems related to heat dissipation and stability of original driver and also to all questions related to usage of LI-Ion accumulators as input voltage. I will test using varying currents (starting from 100mA and going up to 500ma or more, using 10ma increments). Also I will measure the output power BEFORE (pure IR power) and AFTER crystal (green + some residual IR). This should give us an idea about crystal qualiy too. I'm expecting 1/5, 1/7 ratio or maybe worse than that (50mw green from 250/350mw IR or more). We will see...

As indicated above, mine has a 9mm LD. In fact, I think that it may be exactly the same as the 200mw! (Just not over-driven!)

No sure about over-driven problem. Maybe is more related to bad optical assembly, pure quality crystal used and heat dissipation problems.

At the moment, some of us suspect 500mw 808's for both the 100mw & 200mw units (with the 200mw units being over-driven). Current measurements of both units at the proper voltage should get us a better idea on that.

yes and I think that 500mw for 9mm IR diodes inside should be the start point, but we should go up, not down. for a 1/5 ratio IR/green (but I expect to be much more less), 100mw green module should have a minim 500mw IR diode. As time some users reported here 130mw green (mixed green+IR), it mean over 650mw IR. That is the reason for, manufacturer is using TO-5 diodes inside. Not sure till I'll not measure, but more probable high powered diode than good crystals inside. Personally, I'll be glad to find out that crystals inside are very good and IR diodes are very bad...but I am in doubt about that. Also, I'll be glad to find out that most of problems are caused by band optical assembly, because this problem can be corrected. At our days, 0.5-1W (9mm) IR diodes are cheaper. Good quality crystals, still expensive. Be sure, that Chinese people knows better then us this thing.

Actually, we were able to track-down crystals that appeared identical in apearance & size to those in my 100mw unit, and which were claimed by the seller to be capable of up to 200mw.

I suppose that you are talking here about crystal OUTPUT (200mw GREEN - which mean 700-1000mw IR) and not about crystal INPUT. Else, I'm afraid that 200mw IR will give you just 20-30mw green which is not our case.

However, a 1W IR diode at full power, would be too much for these crystals to handle. That is one of the reasons we believe even the 200mw modules may be running (severely over-driven) 500mw diodes!

Crystal quality is important (are sensitive to temperature too so heat could be a real problem - I suggested above a test without original driver board) and I think that actual crystals has a worse conversion ratio but are able to resist over 500mW on input. In this case, a IR diode over 500mW can compensate the worse ratio on crystal output but will add also some additional problems (more unfiltered IR radiation and more heat, meaning more instability). We will see which is optimal for these diodes & crystals after my tests ...

That's the reason I asked roddenberry to take those pics.

Of course, pics are welcome but will not answer to our dilema. Maybe, will remove some variables from our equation... Any additional info till I'll receive modules will be appreciated and helpful for all of us ...

Regards,
Alx

 

[seoguy]

@Benm:

You're absolutely right about the power dissipation in the driver though. If the driver was constructed properly, it would draw the same amount of current at 3.0 or 4.0 volts, and increasing the voltage should not make the laser any brighter.

Correct...assuming you are not feeding the driver more voltage than it was designed for, causing it to go out of regulation. This driver does not appear to have been designed to handle much more than 3V. The fact that the power was increasing with higher voltage should have been an indication that something was wrong.

It might be possible to heatsink the transistor (or fet) to some degree.

Unfortunately, no. The driver transistor only has a tiny tab for attaching to a PCB circuit trace heat sink (which this driver does not even have!) This tab also connects directly to the floating (non-grounded) side of the laser diode, so trying to attach an external heat sink to that could be a real ESD nightmare! There's also no room - the heat-generating resistor is mounted on top of the transistor!

But even with a heat sink, the overriding concern is that this driver transistor is NOT a high-power device - at 4.5V, this circuit is capable of pushing this transistor to FAR beyond it maximum power ratings - even with adequate heat sinking!

The resistor is less likely to be a problem, mainly because those usually survive high temperature operation very well

Same issue with the resistor. The high operating temperature is merely a symptom of the underlying problem. The real problem is the amount of power. At 4.5V and full saturation, that poor resistor is dissipating over 12W of power!

If the driver is constructed well...

The definition of "constructed well" I guess, depends on your needs.

The advantage of this design is that it allows the device to run on only 3V (or even a bit less), without dealing with regulator drop-out voltage, or requiring a complicated & expensive buck/boost design.

It also allows them to control up to 1,000ma or more of laser diode current, using a low power regulator IC.

The disadvantage of this design is that, at these power levels, it has a very narrow range of input voltage, before you start frying components!

For a low-cost, 3V device, this driver design may be great!

But just like you can't feed 12V into a Flex drive and expect it to work, attempting to put more voltage into this thing than it was designed to handle is going to cause problems!

This isn't the first time we have seen this sort of problem crop-up in green lasers, BTW - there have been models of complete lasers that were known to "die" if you tried to run them on higher-voltage rechargeable batteries, right? Perhaps we are now seeing the reason why!


@roddenberry:

But i'll certainly try to provide the images you request as soon as I can. I did unscrew the module and saw the crystal that's glued to the 3/4 brass slug. It is absolutely minuscule, i'll take pictures of that too.

Great, thanks! :yh:


@RA_pierce:

I did some more investigation on my dead 200mW module...
It appears that the diode was slammed with enough current/voltage to obliterate the tiny wires connecting the die to the pins.

Damn! - that's a LOT of current!

Also, When I removed the crystals, there was some sort of sticky adhesive all over the surface of the heat sink which got all over the crystal facet...

That white stuff? I saw the same thing on mine (see my review, post #69), but determined it was outside of the beam path.

But just to be clear here - was this contamination on the output side of the crystals like in mine? Or are you saying that it was on the diode side, blocking the 808 input to the vandate?


@alx:

On my tests, I will remove the original driver and power modules on my regulated power bench supply (0-30V/0-3A) fixing the voltage at 2V (or even less - 1.5v)...

Your tests sound interesting! :yh: However, you might want to test the current and power levels with the factory driver before you start tearing these things apart. I'm also not sure how safe it will be to power the diode directly off a A/C line-driven power supply - even a current-regulated one?

Also note that the operating voltage of at least some of the 500mw 808nm IR laser diodes we have seen, such as this one -

500mw 808nm laser diode TO-5 Package - eBay (item 140339764137 end time Sep-13-09 06:56:42 PDT)

might be as high as ~2.2V, so you may need to give it a bit more voltage to get it to full power.

This should give us an idea about crystal qualiy too. I'm expecting 1/5, 1/7 ratio or maybe worse than that (50mw green from 250/350mw IR or more).

The crystals we found (in post #79) were rated at 70-100mw out with 500mw in. That would correspond to between 1/5 and 1/7. Of course, a good part of that is how well the crystals are aligned in a specific module.

This would all be for the higher-power modules, of course! The low-power ones are obviously using a different diode, as roddenberry reported ~136ma to the driver - that likely wouldn't even be enough current to get mine past threshold! On the lower-power units, I suspect the ratio might also be worse, as the conversion efficiency of SHG crystals goes up significantly with higher power density.

With regards to your other comments, based on what we are observing, it appears that the higher-power units may be driven by a 9mm 500mw 808nm IR LD, that the units were designed for 100mw of green, and that the factory may have been "pot-modding" some of the units and selling them as 200mw.

While this crystal set could handle that, it would require over-driving a 500mw LD to well past it's maximum ratings in order to get that kind of output power.

A lot of what members have reported here about the 200mw units also seems to support that theory.

Of course, pics are welcome but will not answer to our dilema.

Actually, the reason I asked roddenberry for the pics was to see what type/size diode his were using, and more importantly, to see if they were using the same crystal set as the high-power units.

If these same modules are also what is now being used in the current DX True 5's, the fact that members have reported being able to pot-mod those to such incredibly high power levels would also seem to support that!


[Results of latest "live fire" tests done on this module coming next! :yh:]

 

[alx]

Your tests sound interesting! :yh: However, you might want to test the current and power levels with the factory driver before you start tearing these things apart.

NO! Definitely no! First I will just set the voltage at 3V and I'll power the module with original driver built-in, just to have a reference for default current ratings. Here I will measure the power too. I'm expecting to get around 150-160mA for 20-30mw on cheaper modules with default driver.

After that, all test will be made using "another driver" (lab power supply), where I can control better diode. And that is the way diodes should be tested (in case you are not using photo-diode and additional circuit to control the power). And for clear, from what I saw, original modules/driver are not using this feature. Did you imagine, what will be if a manufacturer will use batteries to power/test/control their diodes... No way

I'm also not sure how safe it will be to power the diode directly off a A/C line-driven power supply - even a current-regulated one?

Oh ...is a huge difference. A power supply is acting as a powerful driver, well controlled ... In fact is another kind of "driver" few hundred times more expensive than default driver or a cheaper one. Just ignore the power supply term and read "well controlled adjustable powerful driver".

Finally, after I'll know for sure more about diode/crystal ratings, I will try to see if we can use the default driver, or replace it. Its to early to speak about driver now. But anyway, in case that default driver will not be stable, we already have a cheap linear driver SMD based, which can support higher currents 30-800ma) and can be used (see my thread here: http://laserpointerforums.com/f39/alxs-ld-current-driver-30ma-800ma-5v-16v-22560.html)

Also note that the operating voltage of at least some of the 500mw 808nm IR laser diodes we have seen, might be as high as ~2.2V.

I ordered few types of modules, so will be TO-18 (low powered) and TO-5 (high powered) diodes. Voltage will be increased but not from the beginning (I can adjust booth: voltage and currents). Don't worry, I know what I am doing. Any test will start with safer values.

The crystals we found (in post #79) were rated at 70-100mw out with 500mw in. That would correspond to between 1/5 and 1/7. Of course, a good part of that is how well the crystals are aligned in a specific module.

Aha, so I should lower prediction about ratio, UNDER 1/7! OK, NOTED!

This would all be for the higher-power modules, of course! The low-power ones are obviously using a different diode, as roddenberry reported ~136ma to the driver - that likely wouldn't even be enough current to get mine past threshold! On the lower-power units, I suspect the ratio might also be worse, as the conversion efficiency of SHG crystals goes up significantly with higher power density.

Low power modules are using TO-18 diodes (my guess is for less than 300mw CW IR diode, no or small overload)
High powered modules are using TO-5 diodes (my guess is probably for 500mw IR diode or more). All I want to know is if these diodes are overloaded or by default will support higher currents, over 500mA).
Booth units above are using the same driver. I have just a doubt related to crystals inside... are the same or not?

With regards to your other comments, based on what we are observing, it appears that the higher-power units may be driven by a 9mm 500mw 808nm IR LD, that the units were designed for 100mw of green, and that the factory may have been "pot-modding" some of the units and selling them as 200mw.

All right, so we know for sure that ONLY 100mw and 200mw modules contain TO-5 diode. Pot-modding is not meaning that diodes inside are overloaded. Maybe diodes are ok and support higher currents without problems, but crystals are very bad. And this is what I want to determine!

While this crystal set could handle that, it would require over-driving a 500mw LD to well past it's maximum ratings in order to get that kind of output power.

how can be sure about that? Increasing the current, is not mean that will over-drive a diode.

A lot of what members have reported here about the 200mw units also seems to support that theory.

What will be the worst scenario is to find out that even on high powered DX modules reside:
- very bad crystals (poorer quality)
- one 250/300mW CW IR diode, overloaded (500mA++ for 500mw++)

Actually, the reason I asked roddenberry for the pics was to see what type/size diode his were using, and more importantly, to see if they were using the same crystal set as the high-power units.

Yes, I know, but his pics are not so good and we can't see to much.

If these same modules are also what is now being used in the current DX True 5's, the fact that members have reported being able to pot-mod those to such incredibly high power levels would also seem to support that!

I suspect to be the same... but I would like to be sure about that!

Regards,
Alx

 

[Benm]

@Seoguy,

I see your problem with how this thing was designed - and its not something i would have done so myself if it had been my job.

The concept that lasers produce more power when fed a higher voltage, is based on a long tradition of bad driver design. If you design a proper current source, upping the voltage will do absolutely nothing, unless the regulating components (transistor) have to dissipate too much and overheat.

In reality, virtually all low cost laser pointers have bad drivers, that will not regulate current well. Power will increase with applied voltage, and instead of burning out the driver transistor, its often the laser diode that blows in the end.

The concept that more voltage equals more power should not fundamentally be such, but experience with badly designed drivers has everyone believing so... perhaps even to a point where they will destroy a properly designed driver by overloading it.

 

[seoguy]

@Benm:

I would agree. I was simply trying to look at it from their designer's viewpoint. If this module was designed for making pen hosts that are powered by a couple AAA's, then this driver design may work great - for it's intended application.

In order to allow a variety of input voltages, and still be able to provide such high current (up to 1A or more) to that monster 9mm 808nm IR LD with less than 3V in, would have likely required a much more complex / expensive design.

In reality, all drivers have a limited input range in which they will operate properly - we're just used to drivers that have a wide-enough range that it isn't a major issue!

But I would point-out that neither the rkcstr nor the Flex are capable of doing what this driver can do. The Flex comes the closest - but the cost of just that driver is nearly as much as what I paid for the entire DPSS module!

And in all fairness to DX, they do specifically list this as a 3V device.

The concept that more voltage equals more power should not fundamentally be such, but experience with badly designed drivers has everyone believing so... perhaps even to a point where they will destroy a properly designed driver by overloading it.

Or even a badly designed one! But you are correct - if you want to adjust the current to the LD, that's what the pot is there for! Trying to adjust the current by increasing the voltage to the point that the driver is malfunctioning is simply insanity. Seeing how that output circuit is designed, when I read what voltages ppl were pumping into these things, I cringed!


@alx:

NO! Definitely no! ...

I don't know why you would say that, and then in the rest of that paragraph agree with what I was suggesting!

A power supply is acting as a powerful driver...

Actually, a proper driver is more than just a regulated power supply - it also has additional circuitry to protect this sensitive component! A typical "bench" power supply running off of A/C line current, often has short transients, spikes, switching noise, and other brief variations that, while good enough to be perfectly acceptable for other applications, can KILL a highly sensitive laser diode!

There have been multiple stories here of ppl connecting a regulated power supply directly to a laser diode and destroying it!

Because of these problems, one person constructed a machine designed specifically to "curve test" laser diodes, which utilizes a fancy laser-show type driver circuit (much more sophisticated than the simple drivers we use here!), with computer-controlled, electronically adjustable current!

Rather than drive the diode directly off a bench supply, the safer approach is use an adjustable laser diode driver, connect a 1 ohm resistor in series with the LD, and measure across that.

Aha, so I should lower prediction about ratio, UNDER 1/7! OK, NOTED!

Actually, for the 100mw units, unless they are badly mis-aligned, I would expect that 1/5 to 1/7 should be about right. The 200mw modules should be better, and the lower-power modules (if they are using the same crystals), likely worse.

All right, so we know for sure that ONLY 100mw and 200mw modules contain TO-5 diode.

No, not yet. We know that the 100mw & 200mw use a 9mm open-can diode. We strongly suspect that the 30mw may use a 5.6mm, but still not sure of what type yet (that's one of the reasons I asked for the pics! ).

But as far as I know, we STILL don't know what size the 50mw is using!

Has anyone here ordered the 50mw module yet?

how can be sure about that? Increasing the current, is not mean that will over-drive a diode.

Because at maximum rated power, a 500mw diode would only produce about 70-100mw of green using those crystals.

very bad crystals

No indication of that. In fact, from what ppl have reported here, the crystals seems to perform quite well, given their thin diameter!

one 250/300mW CW IR diode, overloaded (500mA++ for 500mw++)

I can tell you from my own recent current tests on my 100mw module, that that is definitely not the case!

All indications seem to be pointing at 500mw for the high-power models.

Yes, I know, but his pics are not so good and we can't see to much.

Um, I think you may be looking at the wrong pics? roddenberry's close-up picture (post #97) was VERY good! Perfect lighting and focus, you can even see the machining on the surface of the brass, and the tiny SMD circuit traces on the driver board! :kewlpics:

If his new pictures are anything like that one, I have no doubt that they will prove useful in figuring the lower-power modules out! :yh:

 

[seoguy]

Last week, I fired up my new 100mw for the first time, to see what it could do! :yh: I hot-wired it with what parts I had on-hand at the time. The initial report of these first trial runs can be seen here -

http://laserpointerforums.com/f45/100mw-beam-appearance-aaas-current-43301.html

But the highlights are as follows -

• Splotch size noticeably larger, and at least 4x brighter, than my 10mw.
  
• Big resistor stayed cool.
  
• Base of module got slightly warm.
  
• Beam not visible in lit room at night.
  
• In semi-dark room at night, beam appearance was (disappointingly) not much different than my low-power ones - not solid, very light in color, with bright speckles.
  
• Beam coming out at an angle.
  
• Beam very thin-looking.
  
• Outside in night sky - beam visible, but not overly impressive.
  
• Moving beam from vertical to more shallow angle (so passing through more atmosphere), appeared to get more solid-looking and a little bit fatter at a distance.

Overall, was very disappointed in beam intensity - expected 100mw to be MUCH stronger than what I was observing with this module! :cryyy:

Theorized as to possible causes for low power output I was seeing -

1) Mis-aligned components I had already noticed in my initial review of this unit blocking part of beam and causing a loss of power? (as had been also reported by RA_pierce)

2) Was powering this with what I had laying-around at the time - 2 brand-new alkaline AAA's. But given the large, open-can 808nm laser diode this thing has, even if it's only 500mw, it still likely takes ~150-200ma just to get it past threshold, and perhaps as much as 600ma to get it to 500mw (and even more if they're over-driving it!)

Perhaps AAA's just don't have enough horsepower to drive a laser diode this big?​

So I posted the following questions -

What is a 100mw green beam suppose to look like? Should you be able to see it in a lit room at night?

and...

Do AAA batteries have enough horsepower to fully power a 100 or 200mw module with a large open-can IR 500mw diode?

Or is this thing gonna get a heck of a lot brighter if I hook-up some larger batteries to it?

After several days without a single reply, I went-out and got some bigger batteries, and ran a second set of more detailed, metered tests Sunday night.

I now know the answer to the battery questions! :yh:

I am still interested in hearing what others have to say about the typical appearance (indoors & out) of a 100mw beam, however!

Following is the results of my second rounds of tests...

 

[seoguy]

Latest "Live-Fire" Test of DX 100mw Module!

As the performance in the first tests of this device were less than impressive, the new tests were designed, in part, to test-out the "battery theory" - by testing the performance of this module with different kinds of batteries! :yh:

In order to determine the amount of available "horsepower" and performance of each battery type with the new DX module, each of these "static" tests was also metered, to determine the amount of actual current that battery type was supplying to the module.

[NOTE ON READINGS - This meter was purchased to measure very low-current (microamps) from sensors. The flip side of this is that in order to measure the high currents that this high-power DX module requires, I have to use the 10A setting on the meter. This limits the resolution of these current measurements to be rounded to the nearest 10ma.]

First tests were done with the new AAA alkalines taped-together that had been used in the previous tests. Current delivered to the module was measured at 0.43, or ~430ma.

Performance was the same as reported previously. :cryyy:

[NOTE - For the following tests, a 4-battery module from a flashlight was "hot-wired", to supply 3V from two batteries]

Next, two partially used, but still good, Westinghouse "Extra Heavy Duty" AA batteries from the flashlight were connected. Current delivered to the module was measured at 0.32, or only ~320ma.

Performance was poor, spot size/intensity was dim, perhaps about the same as my 10mw! :cryyy:

It was interesting, given the larger size, that the smaller AAA's were able to deliver so much more current! (Apparently, alkalines make a BIG difference! )

Next, two brand-new, Eveready "Gold" alkaline AA's were connected. Current climbed, and after a couple seconds, stabilized at 0.53, or ~530ma!

WOW, what a difference!!! :yh::yh::yh::yh::yh:

Spot size was now SCARY bright , even from 30' away!

Beam now just barely visible in a lit room at night. (Estimate beam was only ~6' away from a bare 23W (100W equiv.) CFL at the time)

Power now seemed a bit too scary for indoors!...

So let's see how it does outdoors in the night sky! -

Beam looks solid, with the atmospheric layer cut-off at the top when vertical clearly visible, making the beam look "short".

When moved from vertical to a more shallow angle (so passing through more atmosphere), beam solid and clearly visible, end does appear to widen slightly at a distance.

When bounced-off the side of a very large off-white building I would estimate at least 100 yards away, splotch was FREAKISHLY bright, like what the spot on my 10mw might look like from only a couple feet away!

Beam takes a couple seconds to reach full strength (but not as slow as my True 5 takes). Not sure if this is a soft-start feature, or if it is just my LD or crystals warming-up.

Base of module (where LD is) got slightly warm.

Resistor stayed cold.

@530ma current, estimate was driving the LD at, or close to, full operating power! :yh:

Tests seem to indicate that this is indeed a 500mw IR LD.

The fact that this unit was operating so cool, would also appear to indicate that it has some room for increased power adjustment!

As it is set right now (for short duty cycles at least), no heat sinking AT ALL would be required!

I'm not sure what the rough power of the above description would be - perhaps those here more familiar with 100mw performance that can tell us?

But I can say that I am definitely happy with the performance I am getting with the larger batteries! :yh:

So, that answers the battery question.

Which brings-up another important point - If DX is now using these same modules in at least their "True" models (as many of us now suspect), then if say someone bought one of these -

DealExtreme: $36.50 True 100mW Green Laser Pointer Pen Black

then they should take careful note of the following...

AAA batteries (even fresh alkaline ones) do NOT have enough horsepower to properly drive the large LD in these new high-power DX modules to full strength!

So any pen-style hosts based on these modules and that hold 2xAAA, will NOT have enough battery power to run these modules at full power!

If you have one of the high-power (100-200mw) green pens, and were disappointed in the performance, you might consider "hot-wiring" it with 2 AA's as a test. If it gets substantially brighter, it might be worth extracting the module and placing it in a more suitable host, that can hold batteries capable of fully driving it! (Just don't exceed 3V!)

How's that for a handy tip!

And if you were thinking about putting one of these new 100mw or 200mw modules into a AAA pen host - forget it!

(Although I do kinda like the idea that my new module uses a IR diode so heavy-duty, that a standard 2xAAA pen host just doesn't have enough strength to run it! )

 

[ReNNo]

Has anyone here ordered the 50mw module yet?

I did..
I'll post more information about module including current through LD.

 

[jayrob]

DX just refunded my money and said that they will not ship the 200mW green module to the U.S. now...

I ordered it on 7/31! Seems I got the short end of the stick.

 

[seoguy]

DX just refunded my money and said that they will not ship the 200mW green module to the U.S. now...

:wtf:

Did they say why? Wrongly-spec'd? Q/C problems? Just to US, or everywhere? Item is still up on their site for sale right now!

I ordered it on 7/31! Seems I got the short end of the stick.

Definitely! Feel for ya there. :cryyy:

I just ordered some smaller ones today. They & the True 5 listed "In Stock", but now the small one's web page switched to "2-5 days", and the True 5's page switched to "Back Ordered"! :yabbmad:

Are they having a supplier problem or something???

 

[jayrob]

I think I'm going to just order it again and see what happens...

Because some are getting them in the U.S. right?