First 660nm in progress

i haven't slept in over 36 hours im sorry i thought he was using the micro FLEX..... sorry please excuse my stupidity

That's no problem. I ordered the Eagle Pair 190-470/610-760nm because my next laser will probably be 445nm. That saves some cost over two pairs. Plus, I won't be waiting that long for them.

I'll hang on to the T-Rex goggles for a while. They make interesting sunglasses if you don't mind everything looking blue. They make California Poppies look bright red.

Picking up the mail today felt a bit like Christmas. The Eagle Pair arrived from Survival Laser (that was quick!) and so did the TrustFire protected blues and TR 001 charger from DealExtreme (13 days from Shanghai).

The difference between looking at a spot from my 5mW pointer with the Eagle Pair and the fake goggles was like night and day. Certified laser goggles are worth the cost. Thanks for the recommendations.

The TrustFire blues were in excellent condition testing out at 3.99VDC and 3.97VDC respectively. Not bad for $4.73 for the pair and free shipping. The Radio Shack in town wanted $16.95 apiece for protected 14500's, but their prices are often laughable. The TF blues are 1.5mm longer than AA so I must make a simple mod to the Minimag endcap. Outside diameter allowed for a sliding fit with no room to spare.

I may have this 660nm Minimag done this weekend if there are no other snags. I'm curious to see how hot the rkcstr driver gets with the two 14500s.

Once this laser is up and running I'll post photos of the build and special parts. One of the goals of this project is to DIY without using a lathe. I have made use of a belt sander and power drill, though.

Yikes those glasses are FUBAR for sure! I have a pair of the Eagle glasses that are rated OD4+ for 190-400nm & 580-760nm. At first I thought I got duped because shortly after I got them I managed to take a direct reflection (this is why you wear safety glasses kids!) and it was bright as hell still*. I assume it's because these glasses use a reflective coating instead of an absorbing one because when I tested them on my LPM they took my 190mw LOC down to 1mw. I'd love to put those up against an LPM and see what they really block if anything.

Good luck on your build. It's looking good so far!




*In comparison my OD3+ glasses from OEM Laser that covers the 395-540 range (hmm just realized that doesn't cover my green HeNe at 543.5nm) the dot hows up as a dim spot.

I have had terrible luck with red lasers. But, all of which died due to stupid reasons, such as a "preset driver at 340ma" really turning out to be 380ma killing a rayfoss 660nm diode. I have had no luck with a lm317 driver, they all turned out to make my LD's go LED. The last one I killed was a lpc-815 from the lead coming off the diode and then bumping back on, shocking it. But, now I have 2 more rayfoss diodes on the way as they seem to be great, I have another multimeter coming since I made the last one inaccurate (reads 120v as 156v) I wish myself luck LOL Expect a thread from me when they come

Jeez, I'm really pissed. I installed the rkster diver exactly as described with the nebulous on-line instructions using 4x1n4001 plus a 1 ohm resister. It was set for 394mA (got barely warm in 30 seconds) and the damned LOC I got from Modwerx just LED'd instantly today. What in the hell did I do wrong?

This was the test set up last night.. peak 394mV and everything ran fairly cool and fine for the 30 second and 1 minute runs on dummy load. 394mA peak tested on two DMMs with the same results.



Today, the first of my two Modwerx LPC-815 LOCs is toast. It's LED at 392 mV output on the meter (392 mA).

Firing set-up...


Toast... it's LED'd and time to remove. I have 1, that's 1 laser diode left...

I'm jealous.... that looks alot better than my first red build. I wouldn't panic too much if you don't have glasses, just don't look directly at the beam.

These gentlemen are forgetting that its possible to make a 5mW laser as bright as a 1W laser. Most pens are PWM-ed so the lumens can be increased per power. Ever wonder why you could pump 100mA through your high power LD and its not that bright? Its because your trying to direct drive it....

For example, that pen might apply 200mA but at 10khz and at 10% duty cycle to make it legal. (math won't add up, i'm to lazy right now sorry). So its bright, but only for alittle while. Its turning on and off to fast too notice. Hence, wattage is a derivative of joules. (joules/seconds = watts...or something like that?)

So... those blue goggles should be sufficient for what your doing. Just shine it at the wall and look at it through your goggles. If it appears bright, then you should be worried and perhaps make a more expensive investment. If not, your good to go.

As for what went wrong? Did you have a DMM in series with your diode? could you see what current you were actually putting into the thing?. Eitherway, i'd start low then go high. I'd say I haven't run a red past 360mA. To afraid to try it. Your already over driving the diode. So it technically can't be expected to work past that. Also, what do you mean by mv? Isn't the voltage drop 2V or something? You would need more than 394mV to light it I would think.

I corrected mW to read mA in post #22. I had it right on the test but had a typo here. I'm shooting for a 250 mW red. The 4 IN4001 rectifier diodes in series with the 1 ohm resistor as dummy load are supposed to give a mV reading = to mA drive current. I'm OK with that.

The problem I ran into was using those damned alligator clip-type test leads. They are no good for this power level. I'm used to using higher voltage electronics. The test leads don't cut it. I fried the last diode attempting a direct ammeter reading, which I will use next time without test leads. I'm uncertain about the diodes. From what I've read here on LPF they should have stayed lit at 392 mA.

Looks like next weekend before I get to this again. :yabbmad:

The certified Eagle Pair are much better than the cheap T-Rex goggles. I'll post some photos tomorrow for use as a comparison of the two.

did you short out the cap if not that may be what killed it.

Just a note about those goggles I have the same ones and they also let light through but on a LPM after the goggles my 210mw laser drops to <5mw

bennett326 said:

did you short out the cap if not that may be what killed it.

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I may not have done that with the first diode. That could have done it. The second diode went while I was adjusting the driver pot, that's tricky and I think I just blew it. I'm not ready to give up yet and should have better luck next weekend. I'll also be much more careful about handling and possible static discharge.

midias said:

Just a note about those goggles I have the same ones and they also let light through but on a LPM after the goggles my 210mw laser drops to <5mw

Click to expand...

Are you talking about the Eagle Pair?

You should be setting driver current with a test load, and not mess with adjustment pots with actual good LD's attached. If you have a 'dirty' pot you can easy fry a diode.

Those tiny little pots are surprisingly jumpy, dirty or not.

yzer said:

Are you talking about the Eagle Pair?

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No the cheap T-Rex ones.

Now I'm totally confused. I'm not buying a photodiode LPM to run a test myself, though.

Apparently, certified laser goggle testing is very involved. It's better for me to go with goggles that have the CE certified wavelengths etched on the glass. I promised some photos comparing the two goggles. I'll do that today.

http://laserpointerforums.com/f53/t...er-goggles-certifications-software-61056.html