continous operating cute green o-like 50 mW

[flatspinn]

Hi there,

I'm quite new here, so be patient! I ordered a green 50 mW laser from o-lite (has not arrived so far) and I'm thinking about the possible duty cycle. It should be max 1 min. in operation, was the suggestion from o-like.
Is there a (simple) possiblity to reduce the power consumption in order to get a stable continous output? The aluminium housing should be able to pass a good amount of heat outside, but will this be sufficent?
Anyone out here who has experiences with that?
I want to use the laser as an outdoor safety tool (mountains and canyons), enabling me to send signals in case of accident etc. to a rescue team (in the middle of nowhere).

Thanks a lot, have a nice weekend!

 

[Benm]

Its not really possible to change it - the porblem is that the host is just not big enough for continous operation. Tuning it down will not really help - if you adjust current down to say 80%, you'd probably lose about 50% of the green light.

I would suggest buying a red laser instead, those often can run continously, are more mechanically stable, and operate in a very wide temperature range (greens often crap out under 10 and above 35 celcius).

DealExtreme: $27.09 High-Power 200mW Red Laser Pen (Burns Match + Visible Beam Daytime)
is a pretty proven laser. Red may be less visible than green, but for you application i think reliability and temperature range may be more important...

 

[flatspinn]

Thank you for the fast reply! Yes, the stability (also mechanical) is a good point of view. I wanted to get a green because of it's better viewability. I have a red, that is a so called flare, with the beam spread out to a line. But it is not that powerful. So perhaps I will take a strong red one in addition.
I hope the green arrives soon...here in good old Germany ;-)

Bye, I will return to tell, what the green is about in handling and view...
:thanks:

 

[snoutke]

Its not really possible to change it - the porblem is that the host is just not big enough for continous operation. Tuning it down will not really help - if you adjust current down to say 80%, you'd probably lose about 50% of the green light.

I would suggest buying a red laser instead, those often can run continously, are more mechanically stable, and operate in a very wide temperature range (greens often crap out under 10 and above 35 celcius).

DealExtreme: $27.09 High-Power 200mW Red Laser Pen (Burns Match + Visible Beam Daytime)
is a pretty proven laser. Red may be less visible than green, but for you application i think reliability and temperature range may be more important...

Sorry my friend, I can't agree with your suggestion of buying the DX 200mW red.

First, he needs a green, not a red for his rescue purposes since the green color is the most visible color to the human eye. I had that DX 200mW red, and its beam is hardly visible at night, a fact that doesn't help him.

Second, that DX 200mW red has a cheap build and it is a low quality laser (that's why it is so cheap). The focusing is very loose and therefore unstable and the on/off switch malfunctions in a short time leaving you with a laser that can not be turned off...

It is true that it can do all these cool burning tricks, but it is not a reliable laser for survival.

I would recommend this powerful green, once it is restocked.

 

[RA_pierce]

Sorry my friend, I can't agree with your suggestion of buying the DX 200mW red.

First, he needs a green, not a red for his rescue purposes since the green color is the most visible color to the human eye. I had that DX 200mW red, and its beam is hardly visible at night, a fact that doesn't help him.

Second, that DX 200mW red has a cheap build and it is a low quality laser (that's why it is so cheap). The focusing is very loose and therefore unstable and the on/off switch malfunctions in a short time leaving you with a laser that can not be turned off...

It is true that it can do all these cool burning tricks, but it is not a reliable laser for survival.

I would recommend this powerful green, once it is restocked.

Well, the point Benm is trying to make is that green DPSS lasers are unstable compared to diode lasers.
If my life depended on a laser as a "flare" I would choose a diode laser over DPSS.
Diode lasers have a wider operating temperature range where a DPSS laser may output little or no visible light if the temperature is too high or low.

It is understandable that green would be seen as the best choice at first, but when you consider the reliability of direct-diode lasers vs. DPSS, there are significant disadvantages for the DPSS laser.

 

[hakzaw1]

contact DTR about his SOS/strobe/hi-lo 445 -- IMO its the perfect rescue laser. it flashes SOS in two speeds and works w/ a big(bigger than 18650 iirc) rechargeable batt too.

nice build too

hak sez --hope this helps--if so help the forum w/ a small donation please

plus this month you get entered into Moh's super giveaway raffle too

 

[Plan B]

Not sure if you'd want or need continuous operation for a rescue beacon laser. Powerful lasers tend to chew threw batteries pretty quick. You'd need to charge lots up during the day to run it all night while changing them out every other hour. Sounds like DTR's got the right idea. Strobe the laser slow enough so it can run all night. It be nice to have a bypass on the strobe circuit for lighting fires and when you suspect rescue might be in visible range. A powerful 635 nm diode might work well for one of these if money was no issue.

This thread got me thinking about uses of a survival/rescue laser. Other then fire starter and beacon, all I've come up with is blinding some poor little animal so I can beat it with a stick :horse: and eat it after cooking it over the fire I started with my laser. :thinking:

 

[flatspinn]

Hi,
and thanks for your replies. Interesting points of view. Is there a homepage from DTR to have a closer look?
The thermal stability is quite not that easy to solve, I didn't expected that.
Perhaps an additional heatsink would help (case modifying).
I'll see, when the green laser arrives, and I can test it.

Allthough the ratio between sufficent power to have a viewable beam and longlasting batterie consumption will be difficult, too.

By the way: I found here a very helpful forum!

 

[hakzaw1]

click under DTR username on any of his posts/threads-click on send PM and ask him about the SOS 445 laser.

If I were in need of rescue i would NOT run my battery down by using strobe non-stop- at least not until i saw aircraft and knew they had seen my SOS.

lol about temp blinding a potential meal...good idea about firestarting tho--

Bear Grylls will be doing that on 'Man Against Wild' soon---


hak

 

[flatspinn]

Hi there again,

my cute green 50 mW arrived, no problems with the customs at all.
The power of the beam is amazing...
I think it will do just fine as a signaling device, it is really viewable!
Two things:
One is the question about the focus: What ist the normal range of that? How big is the dot at maximum for a distance of e.g. 100 m?

Second: The click-switch seems to be a bit loose (noise when shaken carefully), but the function is ok. Any suggestions with that?

Thanks a lot...

 

[Benm]

Well, the point Benm is trying to make is that green DPSS lasers are unstable compared to diode lasers.
If my life depended on a laser as a "flare" I would choose a diode laser over DPSS.
Diode lasers have a wider operating temperature range where a DPSS laser may output little or no visible light if the temperature is too high or low.

Indeed. Perhaps the DX i suggested is not of sufficient quality, but i was considering something in the price range of the 50 mW olike. More expensive, better built, lasers would obviously be preferable, but money is always a factor, isn't it?

Even a 200 mW green will not be of use if its freezing or very hot (say over 50 degrees). If you don't believe me, toss that o-like in the fridge for an hour and try to fire it up. Chances are there will be little or no green light until it warms up.

Red lasers have no issue with this at all, and would work if you were stranded on the north pole... as long as you feed it batteries that work in the cold.

On the dot size: It depends on the quality of the laser and lens positioning. In an ideal case the divergence would be about 1 mRad, giving you a 10 cm dot at 100 meter distance. At a kilometer the dot would be a meter radius, and not very visible... but your laser will be visible to anyone you hit with the beam. Unfocussing it slightly may actually be a good thing, since you can illuminate larger areas. Even if the dot is something like 10 meters across, your laser will still be the brightest thing to see at night.