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From: Sam Wormley on 25 Feb 2010 19:58 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 25 Feb 2010 20:09 "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 25 Feb 2010 20:40 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 25 Feb 2010 21:52 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 26 Feb 2010 00:20
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? |