From: Sam Wormley on
On 2/25/10 2:20 PM, Raymond Yohros wrote:
> On Feb 25, 11:21 am, "mary"<nos...(a)invalid.com> wrote:
>> "Raymond Yohros"<b...(a)birdband.net> wrote in message
>>
>> news:988d1a4a-5b3b-40d8-ad08-160b7ec67234(a)v20g2000yqv.googlegroups.com...
>>
>>> i'm having big problems with this lasers.
>>> i have 6 units and they are all gone.
>>> one with under 4 hours of use!
>>> does anybody know if there is a problem
>>> with production with this type of dpss units?
>>
>>> regards
>>> r.y
>>
>> your probably running them too hot. Have big heatsink w heat compound, and
>> run it at low power.
>>
>> Google is your fiend
>>
>> In a 473nm blue DPSS laser, there's a BIG infrared laser diode that
>> generates laser light at 808nm, this is fired into a crystal called Nd:YVO4
>> (containing neodymium yttrium vanadium oxide) that lases at 946nm; this
>> laser radiation is finally fired into a crystal called LBO (containing
>> lanthanum boron oxide) that doubles the frequency to 473nm - the bright blue
>> color you see. This light is then collimated (focused) by a lens and emerges
>> out the laser's "business end". Just before the lens, there's a filter that
>> removes any stray IR (infrared) radiation from the pump diode& Nd:YVO4
>> crystal.
>> You don't want that stuff in your blue beam, trust me.
>>
>> This is why blue diode lasers are so much more expensive than red ones. Lots
>> of itty bitty parts, and they all need to be aligned by hand. If the
>> polarisation is "off", one of the crystals needs to be turned. With red
>> diode lasers, you just slap in the diode and slap a lens in front of it.
>>
>> PROS:
>> Unique, attention-getting color that's radiant and unusual for a small laser
>> Beam is "clean", with no visible speckling or artifacts around it
>> Powerful enough to burn things; but I'd expect that out of a 120mW+ laser
>> Unique, attention-getting color...o wait I said that already.
>>
>> CONS:
>> Fragile interior construction - like all DPSS lasers. Will not figure into
>> my rating
>> Not water-resistant - but most other DPSS lasers aren't either. Will not
>> figure into my rating
>> CDRH warning label is not on the laser or its driver.
>
>
> thanks, i did google it but i dont know if there's a
> particular problem with production with this type
> of dpss. i run them all under very cool enviroments
> with fans and battery regulated backups but all
> the units lost the 473nm dpss, while the 532nm
> and the 650nm units are in perfect condition.
>
> regards
> r.y
>
>

From: mary on

"Raymond Yohros" <bat(a)birdband.net> wrote in message
news:6f7bd226-14a7-462e-84bb-918d0659ea97(a)t23g2000yqt.googlegroups.com...
On Feb 25, 5:39 pm, "n...(a)bid.nes" <alien8...(a)gmail.com> wrote:
> Well, *which* type exactly? Who manufactured the things, and have
> you contacted the maker(s)?
>

yes, they are ALL from china.
i thoath i could save a few bucks but
know im paying the price painfully
4 of them cost me about the same as
a one rgb german unit, but the german unit
will last for more than 10 years without
a problem

>
>> What's the failure mode; no blue at all, reduced power, beam
>> anisotropies (skewing, intensity/polarization variation), how about
>> the IR diode? Do they draw any too little/too much/any at all current
>> from the driving circuit?
>>
>> Did they get really hot just before failure? Do they still get hot
>> when powered? Can you monitor and control the driver current?
>

>no light at all
>no signs at anytime of malfunction
>just going blind after a few hours
>of use suddenly and without
>dimming out.
>the current output to the laser its o.k

>all the 473nm lasers are from the
>same company and, as you may know,
>that pretty color its very expensive!

>regards
>r.y

Sounds like you burned them out.
There is a tradeoff of amount of current used vs lifetime of diode (with
correct heat sink).
You should only operate at 1/2 current in anycase.

Who is manufacture?
How much current are you using? (please measure)
How hot is the device getting? (measure near base)



From: Raymond Yohros on
On Feb 25, 5:09 pm, "mary" <nos...(a)invalid.com> wrote:
> Sounds like you burned them out.
> There is a tradeoff of amount of current used  vs lifetime of diode (with
> correct heat sink).
>

i know, its about 5000 hours for dpss units and
about 3000 hours for ion lasers
as a consumer/artist, i just have to see what is the voltage
requirement and keep the unit cool.

i dont have to open them up to see if they made a
mistake building it!

>
> You should only operate at 1/2 current in anycase.
>

yeap!, thats what i have to find out if they build them
that way!

thanks
r.y

From: Benj on
On Feb 25, 7:58 pm, Sam Wormley <sworml...(a)gmail.com> wrote:
> On 2/25/10 2:20 PM, Raymond Yohros wrote:

Sam-bot SOFTWARE glitch!

Note "Sam Wormley" bot failed to include comments to post. Please
debug software.
From: jerry warner on


Benj wrote:

> On Feb 25, 7:58 pm, Sam Wormley <sworml...(a)gmail.com> wrote:
> > On 2/25/10 2:20 PM, Raymond Yohros wrote:
>
> Sam-bot SOFTWARE glitch!
>
> Note "Sam Wormley" bot failed to include comments to post. Please
> debug software.

can you be sure?