Help PLZ!

So I'm building a laser harp for my 3rd year electronics engineering project and have 2 weeks until its due. We bought a 100mw green laser from dx.com. It took over a month to ship and when it got here, big surprise it doesn't work. I then sought out other crappy lasers, whatever I could get my hands on. But then i tried it again and it worked perfectly. Then the next day it craps out again. This is what I know so far, I get a good resistance when i press the button which tells me the button is not shorted out. There is Infrared coming out as tested with my cell phone, it also passes a diode test. I'm pretty new with lasers and I don't understand how it can work perfectly one minute then only be spittting out infrared the next, any helpful info would be greatly appreciated.:wtf:

The crystals are probably poorly mounted and secured and thus it is drifting into and out of alignment. Not much you can do.

Rip the red diode from a DVD burner and build a suitable constant current source and TTL MOSFET switch for it. That's all you'll be able to do in under two weeks really. You'll have to order the diode mount, lens, and housing module express to get it in in time. Perhaps DTR can send something out special for extra cost to get it to you on time if you don't feel confident in true DIY. It's worth sending an email to him about it.


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Yeah I thought about that already but I don't think a red DVD burner laser would work for my application. I need to be able to see the beam and not destroy my eyes in the process.. Is there no way to realign it myself or is that just impossible?

What the heck is with all these laser harps recently...

beeman519 said:

Yeah I thought about that already but I don't think a red DVD burner laser would work for my application. I need to be able to see the beam and not destroy my eyes in the process.. Is there no way to realign it myself or is that just impossible?

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It can be done, but only by someone who knows what they're doing. for most cases, its not practical. I do DPSS work, and its not easy any way you look at it. fractions of a mm count, and everything is fragile as *censored*

a laser harp eh.... *proceeds to ponder*

Plus you need 808nm and 1064nm blocking goggles to do realignment work. NO EXCEPTIONS.

The red diode can be used you just need a fog machine. Even 25mW of red can be used for a harp with fog.

You're left with two options; readily available diode + full DIY or express order a module not from china. Take your pick.


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Check out this one.