Laser got substantially dimmer?

[seoguy]

I bought a Chinese pen-type red laser off eBay recently. It came without any sticker at all, and was out-of-focus, but once I adjusted that, appeared to be at least 2x as strong as a nice keychain I have that is rated at 5mw.

But now it has gotten noticably dimmer. At first I thought it needed new batteries, but I put in brand-new ones, and it is still a lot dimmer than it used to be. How can I fix this?

 

[Ieon]

I bought a [highlight]Cheap[/highlight] [highlight]Chinese[/highlight] pen-type red laser off eBay recently.  It came without any sticker at all, and was out-of-focus, but once I adjusted that, appeared to be at least 2x as strong as a nice keychain I have that is rated at 5mw.

But now it has gotten noticably dimmer.  At first I thought it needed new batteries, but I put in brand-new ones, and it is still a lot dimmer than it used to be.  How can I fix this?

I fixed your post ;D

 

[Th0ughts]

[quote author=seoguy link=1235619630/0#0 date=1235619630]I bought a [highlight]Cheap[/highlight] [highlight]Chinese[/highlight] pen-type red laser off eBay recently.  It came without any sticker at all, and was out-of-focus, but once I adjusted that, appeared to be at least 2x as strong as a nice keychain I have that is rated at 5mw.

But now it has gotten noticably dimmer.  At first I thought it needed new batteries, but I put in brand-new ones, and it is still a lot dimmer than it used to be.  How can I fix this?

I fixed your post  ;D
[/quote]
Get out of here, Ian.

Now, back to OP: The only reason a laser would dim is if the batteries died, or the diode died. How dim is dim? Can it still make a dot around 20 feet away in the dark?

 

[Deleted member 8382]

Cheap chinese + ebay = fail

 

[Ieon]

[quote author=Ieon link=1235619630/0#1 date=1235629515][quote author=seoguy link=1235619630/0#0 date=1235619630]I bought a [highlight]Cheap[/highlight] [highlight]Chinese[/highlight] pen-type red laser off eBay recently.  It came without any sticker at all, and was out-of-focus, but once I adjusted that, appeared to be at least 2x as strong as a nice keychain I have that is rated at 5mw.

But now it has gotten noticably dimmer.  At first I thought it needed new batteries, but I put in brand-new ones, and it is still a lot dimmer than it used to be.  How can I fix this?

I fixed your post  ;D
[/quote]
Get out of here, Ian.

Now, back to OP: The only reason a laser would dim is if the batteries died, or the diode died. How dim is dim? Can it still make a dot around 20 feet away in the dark?[/quote]

Well... it's true.

Ebay lasers fail, if you buy cheap chinese lasers off ebay don't expect them to last.

 

[seoguy]

How dim is dim? Can it still make a dot around 20 feet away in the dark?

Yes. It used to be at least twice as bright at a distance (>100') as a 5mw keychain one I have.

Now, it is noticably dimmer than the keychain one close-up (at a few feet, perhaps 1/2 as bright as the keychain), and nearly invisible at a distance!

It is still lasing, and not acting like an LED, as I can still see that backscatter "effect" lasers make on a surface. And it is still in good focus. But I would estimate it is perhaps <=20% as bright as it was when I first got it.

My first thought was the batteries, but when I switched to new, better batteries (started-out with the cheap carbon ones, switched to alkaline), it was just as dim!

I suppose the new batteries could also be bad, but I just bought them, and they are dated to 9/2013, so that seems unlikely as the cause.:question

 

[Ieon]

How dim is dim? Can it still make a dot around 20 feet away in the dark?

Yes.  It used to be at least twice as bright at a distance (>100') as a 5mw keychain one I have.

Now, it is noticably dimmer than the keychain one close-up (at a few feet, perhaps 1/2 as bright as the keychain), and nearly invisible at a distance!

It is still lasing, and not acting like an LED, as I can still see that backscatter "effect" lasers make on a surface.  And it is still in good focus.  But I would estimate it is perhaps <=20%  as bright as it was when I first got it.

My first thought was the batteries, but when I switched to new, better batteries (started-out with the cheap carbon ones, switched to alkaline), it was just as dim!

I suppose the new batteries could also be bad, but I just bought them, and they are dated to 9/2013, so that seems unlikely as the cause.:question

multi-meter the batteries if its around 1.5v there good, I'm sorry but I think your diode is well "degrading" meaning its dimming same thing has happened with alot of my cheap 5mw lasers, how much did it cost anyways and let me guess its 5mw red?

 

[Deleted member 8382]

Seoguy, buy the dx30 / dx50

Those are 99% good units for the best price you will nver find. I'm using it

 

[seoguy]

Good idea, Ieon. But I'm thinking they may perform differently under load than connected to a VM?

BTW, it came without any laser power label, and listed on the customs form as a "pen". I got it because I saw an identical-looking one f/eBay reviewed at LED Museum, who said he had to call it a "module" because of it's measured power level.

Seoguy, buy the dx30 / dx50

Those are 99% good units for the best price you will nver find. I'm using it

Hallucynogenyc, I would LOVE to, they have some insanely cheap prices (50mw greenie <$21 w/ship, 200mw red burner <$41 w/ship!), but they refuse to ship good stuff to U.S.!

 

[Ieon]

Good idea, Ieon.  But I'm thinking they may perform differently under load than connected to a VM?

BTW, it came without any laser power label, and listed on the customs form as a "pen".  I got it because I saw an identical-looking one f/eBay reviewed at LED Museum, who said he had to call it a "module" because of it's measured power level.

Seoguy, buy the dx30 / dx50

Those are 99% good units for the best price you will nver find. I'm using it

Hallucynogenyc, I would LOVE to, they have some insanely cheap prices (50mw greenie <$21 w/ship,  200mw red burner <$41 w/ship!), but they refuse to ship good stuff to U.S.!

Unmeasured power heh? I'd say its 5mw then. most 5mw pointer keychains are lower then that, proberly why its looks brighter.

Theres some guy in canada on the fourm that you can place a order and he pays DX they ship to him and he ships to you.

So really it's a win win.

EDIT: Laser over 5mw are ILLEGAL in usa to import so beware if your laser gets caught they will send you a warning then if you do it again big fine and prison!!

 

[rog8811]

It may be worth checking the threads that join the laser together are clean, these lasers use the case for the earth return. Dirty threads or battery contacts will cause high resistance which will under-drive the laser.

Regards rog8811

 

[Ieon]

It may be worth checking the threads that join the laser together are clean, these lasers use the case for the earth return. Dirty threads or battery contacts will cause high resistance which will under-drive the laser.

Regards rog8811

Listein to this guy he knows his stuff

 

[seoguy]

OK, rog8811, will try that - thanks!