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cheap, AAA powered, ~20-30mw blue pen?

manamana

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I've had an idea for some time for a photography project that involves a blue laser. Previously when I looked into it, they were too expensive, then the 445 projectors hit and I assumed in a few months there would be all manner of inexpensive blue lasers around. But checking in it looks like all the action is in the ~500mw and up range.

So if I was looking for a cheap (say <$70) blue pen, what are my options right now?

Thanks,
 

anselm

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So if I was looking for a cheap (say <$70) blue pen, what are my options right now?
Bad.
Problem is not the low power, you can easily tone those 445nm diodes down to 50mW or even less.
The diode itself costs 45~50$, then you still need a lens, pen and driver.
You might get away with that price if you're clever and can build it yourself.
Hey, I built me a 445 laser for about that money your willing to spend, but it's not a pointer.;)
 

rhd

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If 405nm violet would work, you could get one of those cheap.
 

midias

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You can get a diode for 45 to 50 then a cheap 405nm pen and swap the diode and turn up the current on the driver. That should get you ~20-30mw. I have made my own but it was closer to 90 dollars using a flex drive.
 

rhd

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You can get a diode for 45 to 50 then a cheap 405nm pen and swap the diode and turn up the current on the driver. That should get you ~20-30mw. I have made my own but it was closer to 90 dollars using a flex drive.
If he is okay with 20-30mW of violet, then buying a cheap 405nm pen may actually provide this without swapping anything at all.

If he needs 445nm blue, then I'm not sure if a 445nm could even run that low. But regardless, I think using a 405nm pen as a host is a bad idea.

A 405nm pen would cost you $10. Why not spend ~$15 for a proper housing, and LM317 driver, and know that you had done it properly? If this is for an art project, I doubt he needs a whole host.
 

midias

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If he is okay with 20-30mW of violet, then buying a cheap 405nm pen may actually provide this without swapping anything at all.

If he needs 445nm blue, then I'm not sure if a 445nm could even run that low. But regardless, I think using a 405nm pen as a host is a bad idea.

A 405nm pen would cost you $10. Why not spend ~$15 for a proper housing, and LM317 driver, and know that you had done it properly? If this is for an art project, I doubt he needs a whole host.
I know for a fact the 445 will run that low I have one running at about ~20mw using a flex drive at ~200ma and 2 AAA batteries in a pen host. The advantage of using a new wish style pen is you get a boost driver and a host for under 10 bucks that you only need regular AAA batteries instead of a few Li-ion batteries for over 7V. Another member did it here and it turned out great.
 

Blord

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I did it. I bought a cheap Ebay 405nm pointer and just swap the diode into a 445nm. Turn the pot to ~225mA, just enough to lase the diode.

This is not 405nm but a 445nm diode.
 

Leodahsan

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@Blord
Hmm, so you are the one who owns that pen. What about the pen's heating?
And.. whats the original price of the pen (405nm)?
 

DJNY

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I would buy the diode from a member here. DTR has them for less than the ebay price.

I have a 30mW 445nm pen I can sale you. Click onto my rainbow pic in my signature, it´s the silver one.

I would sell it for $120 + shipping. PM me if you´re interested.
 

kcorbhv

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where can i get one of those 445 diodes from that will take credit card and is reputable? and are they the same diodes as the ones in the DL spartan blues(400mw and 1w)?

thanks
 

manamana

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well I've placed my orders. Does anyone have any tips or guides for opening up and adjusting the driver on the cheap pens? I've got a red one and I'm not sure how I would get at the diode. The front cap comes off?
 

manamana

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So I got everything and got it assembled. A few things I've come across:

-when turning the pot, there's a fine line between "barely visible" and "holy brightness"
-it does run kind of warm.
-seems to diverge quite a bit. It's a dot from 12" away. From 20' away it's a line 1" wide and ~5" long. lens alignment?
 
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So I got everything and got it assembled. A few things I've come across:

-when turning the pot, there's a fine line between "barely visible" and "holy brightness"
-it does run kind of warm.
-seems to diverge quite a bit. It's a dot from 12" away. From 20' away it's a line 1" wide and ~5" long. lens alignment?
Sounds right. Try turning the lens to change the focal point. Good news is you really cant kill it, unless it over heats. That driver wont put out enough power to kill the diode, so feel free to play.
 

DrSid

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How do you dismantle hosts like this ? Do you have some pictures of the insides ?
 

midias

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So I got everything and got it assembled. A few things I've come across:

-when turning the pot, there's a fine line between "barely visible" and "holy brightness"
-it does run kind of warm.
-seems to diverge quite a bit. It's a dot from 12" away. From 20' away it's a line 1" wide and ~5" long. lens alignment?
Sounds about right when I was tuning mine I noticed it had a threshold about 200ma where it changed about 10x in brightness.
 




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