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200mW Green Pen from FocalPrice $74.61

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yep - that's where the warning label is on mine (crooked, too!) ... The yellow label is one I put on there to help discern between this and other pen-styles I have that are all different power outputs.

Don't forget to put fresh alkalines in, BTW - I've had many, MANY Chinese lasers come with dead or on-their-last-legs batteries!
 

jwc

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I popped some slightly better (2.94V combined reading on my multimeter) batteries in there and there's a small but definite improvement. It's unfortunate that the driver is so bad that it requires such a high voltage.

I think I'm going to buy a 10440 battery and if I can find a potentiometer on the driver board, I'll tune that to compensate for the large voltage increase.

One thing that I found mildly disturbing: when I was using a rechargeable battery, it barely lased green. However, because the green was so dim, I could see the red from the IR pretty well on a surface about 3 inches away.
 
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Sounds like you've got some bigger problems than you know if you can see IR ... Because IR isn't visible to the human eye. Sounds bad - send it back, even though FP hasn't got the best rep for customer service they really should replace this. Keep us posted
 

Lotus_Darkrose

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Yeah lol, I can understand seeing faint red from the 808, but its always 1064 coming out if its going through the crystal right? (And no I don't mean if it's properly aligned and putting out 532)
 

Warske

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Lotus_Darkrose said:
Yeah lol, I can understand seeing faint red from the 808, but its always 1064 coming out if its going through the crystal right?
Depends on how it's constructed.

On some, the 808 nm from the diode blasts into the back of the crystal and right around it to go out the lens too (see pics).

If you hook these up to a bench power supply and turn down the voltage, you can get to a point where the 808 nm laser is going, but not bright enough to start the green lasing action. Then you can clearly see the red from the 808 nm. It is not a tight spot, though, because it focuses at a different point.
 

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Warske

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jwc said:
As for the power output, it's nowhere near what BrewCityMusic was reporting.  If I were to guess, I'd say maybe 50mW if I'm lucky.
If I am looking at the same one, it says "Power consumption: 200mW"

If it takes 200 mW from the batteries, getting 50 mW of green out might be about right.

http://focalprice.com/product_6498.html
200mW 532nm Green Laser Pointer (Black)
SKU: LP041B
Price: $ 44.7
 

jwc

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Well I did some testing...

I made a quick voltage regulator with an LM317 (no, sadly, I don't have a bench PSU) and tried the laser at different voltages.

First, I tried my LEDshoppe laser. At 3V, it was much brighter than what it was doing on rechargeables. I didn't go much above that, though. It drew a couple hundred mA.

Then, I tested this laser more rigorously. At 2.6V, it drew about 400mA. 2.7 was 470mA or so. I then ramped the voltage up to 3V, where it drew 600mA. Briefly, I ramped the voltage up to 3.7V just to see what it would do. It still drew only 600mA, though.

2 Ni-MH AAA's have a voltage of about 2.6V or so IIRC, so the laser will barely work on rechargeable batteries.

Since the current draw isn't any higher once you reach 3V, I think that if I stick a 10440 in there with a spacer, I'll be okay... I'd rather not spend a ton of money on Alkalines (which also have plenty of voltage sagging problems, too). :D
 
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What does it do at 4.2v? You may run into issues, but a freshly-charged Lithium puts out around this.

Edit: If it drew the same current at 3v and 3.7V, there is more energy going into it - you might notice the chips getting warm at 4.2V, or extra current going through the IR diode. (though that's less likely). Another thing you might want to do is record beam shape and look for mode-hopping in it when run off a lithium battery.
 

Warske

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jwc said:
Since the current draw isn't any higher once you reach 3V, I think that if I stick a 10440  in there with a spacer, I'll be okay...
If you are concerned about giving it too much voltage, you could put a diode or resistor in the spacer to drop the voltage back down to about 3 v.
 

jwc

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All right, I got my 10440s today, so I built a spacer:




The results were pretty darn impressive (~50mW pointer on the right, the FocalPrice pointer on the left).


I don't know how long it's going to last, but it'll be fun in the meantime... :)

If you're interested in the details:
http://blog.jwcxz.com/?p=377
 

Benm

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It probably reaches regulation from 3.0 volts upwards, so i suspect you should be okay as long as the driver can handle the extra dissipation.

Yeah lol, I can understand seeing faint red from the 808, but its always 1064 coming out if its going through the crystal right?
1064 should never come out really, since the doublers are almost always intra-cavity in the solid state laser. This requires HR mirrors or both ends of the solid state laser to work under any circumstance, making a significant 1064 leak very unlikely.

Also 1064 isnt really visible at the power levels used in these lasers - if you can ever see 1064, seek medical advice right there.
 

jwc

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It probably reaches regulation from 3.0 volts upwards, so i suspect you should be okay as long as the driver can handle the extra dissipation.
Yeah, that was my guess too, based on some earlier testing I did. There was no appreciable current change after about 3V. I stuck a diode in the spacer in order to dissipate some of the heat there instead of at the driver board.
 
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Wow lucky!

My friend ordered the same laser that failed to beat his 30MW TRUE.

I think you got lucky, I wouldent buy again from these guys,a lot of people got crappy ones.

I was a click away from getting it before I read the bad reviews of FP, what really made me almost cget it was the keylock though.
 
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I orderd the 50 satin from focal and it came black, after 3 weeks...

CRAP!!!!!!!!!!!!!!!!!!!!
 
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