Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



@#!%@$@#@$$@%@#@!!!!!!!!!!!!!!!!

Daedal

New member
Joined
May 23, 2007
Messages
2,277
Points
0
Ben, I agree about the COD factor. It living through it makes it really astonishing to me. It really probably wasn't much more powerful than running it at 300mA, and probably only a couple mW more powerful. The excitement was actually keeping it alive for as long as it did, and still have it running to this point ;D

I personally am very amazed at its ability to sustain massive abuse and stay alive. I'm right now trying to figure out the best power for pulsed operation. :)

--DDL
 



Gazoo

Active member
Joined
Jun 9, 2007
Messages
3,199
Points
38
Daedal,
Was the match sharpied... ;D Was it a safety match????? More info please... ;D I must now try for 21 feet.. :p
 

Daedal

New member
Joined
May 23, 2007
Messages
2,277
Points
0
;D

it was a sharpied safety match. The only ones I have are red matches and no matter how hard I try never lite up unsharpied... :-?

--DDL
 

Gazoo

Active member
Joined
Jun 9, 2007
Messages
3,199
Points
38
Daedal said:
;D

it was a sharpied safety match. The only ones I have are red matches and no matter how hard I try never lite up unsharpied... :-?

--DDL
I have the same matches and it lit right up at 8 feet....unsharpied...
 

Daedal

New member
Joined
May 23, 2007
Messages
2,277
Points
0
:eek: :eek:

Probably not the same matches... I couldn't get it to lite up from 6 inches with a 250mA drive and the laser is the size of a needle tip.... :(

--DDL
 

Gazoo

Active member
Joined
Jun 9, 2007
Messages
3,199
Points
38
Interesting...I have been able to get a white headed match to light easily at a foot with 250ma's. And with the GB diode.
 

Daedal

New member
Joined
May 23, 2007
Messages
2,277
Points
0
Maybe not ones that are 2 years old, have gone through all kinds of Florida humidity and weather, and perhaps not the same brand. The ones I have are rather hard to lite, even striking it against the book itself... I think I need a replacement soon... ;D What to do with the 500 matches I have still...

Hmm... ::) I got it! I'll just make a really long line of matches and lite them all at once... ;D ;D That'll be fun! ;)

--DDL
 

Benm

Well-known member
Joined
Aug 16, 2007
Messages
8,113
Points
113
Daedal said:
Ben, I agree about the COD factor. It living through it makes it really astonishing to me. It really probably wasn't much more powerful than running it at 300mA, and probably only a couple mW more powerful.
Perhaps, i have no method to measure output power, so i can't create a decent current-vs-power curve at all, and just go by the one in the datasheet. That seems to go straight up to 250 mW and over though.

Running at 220 mA i was able to light a brownish-headed safety match about 5 feet away with some effort.

Also, i find the relation between temperature and power at a given current quite noticeable. When i dial in 180 mA for example, i notice the power dropping in a few minutes because the module heats up. There is no damage though, when i allow it to cool it works as well as it ever did.
 

Hemlock_Mike

Well-known member
Joined
Jan 7, 2007
Messages
6,284
Points
83
Hey -- someone pushing the limits !!!!

I pushed a GD LD to 500 mA but I discovered that after about 350 mA, the output increase has leveled off and added mA's do little for increased output. There is a knee in the Po vs mA curve. Pass that and all you get is mode hopping and DEATH of the LD :( I pushed one of SenKats GB diodes repeatedly to ~500 mA and found out that I had a defective diode !!!!!(joke)

Some of them will be better than others but over 350 mA appears to severely limit life. Again -- When exploring the outer limits, watch the meters. When you see a leveling of output or visually see the spot blur (mode hopping) ----
Turn it down NOW.

Mike
 

Daedal

New member
Joined
May 23, 2007
Messages
2,277
Points
0
Agreed Mike... If anyone knows about killing the diodes, it's you... and I mean that in a good way... ;D

--DDL
 

Benm

Well-known member
Joined
Aug 16, 2007
Messages
8,113
Points
113
Hemlock Mike said:
Some of them will be better than others but over 350 mA appears to severely limit life.  Again -- When exploring the outer limits, watch the meters.  When you see a leveling of output or visually see the spot blur (mode hopping) ----
Turn it down NOW.
Would you state that driving these diodes (passively cooled) at 350 mA is safe to some degree, as long as no odd effects appear in the beam?

Also, as you have blown up quite a few as i understand, is there any indication in the voltage drop at a regulated current that indicates the onset of problems?
 

Hemlock_Mike

Well-known member
Joined
Jan 7, 2007
Messages
6,284
Points
83
If you graph the LD current vs Po, you will see a knee (leveling curve) in the graph showing that the diode is at it's limit.  Back-off !!!
Also, If you view the beam (unfocused), you should see the output becoming unstable.  Back-off.  
The diodes will only take this for a while even with TEC cooling.  
Enjoy the power for a moment -- don't let it corrupt you !!!!

Mike

PS: I don't monitor voltage because these devices opperate with current. The current will just keep going up. It might be interesting to see if there is a voltage anomoly which happens near the upper end.
 

laserrod

New member
Joined
Aug 3, 2007
Messages
342
Points
0
LASERs must give more output when cool :cool:

I know the first research LDs only worked when liquid N2 cooled.

IDEA:
TEC cool the LASER/AXIZ/LENS real cold. Then to combat the lens frosting use a output
aperture tube, let's say 1" long and butted up against the output lens; then blow disicanted air(moisture free) into the tube by useing bypass air presure from the TEC cooling fan filtered through baked epsom salt (or equiv.) media screened canister then directed into the aperture tube. Canister must be easly replaceable. Rebaked in MW oven to boil moisture out.
Waterproof appropriate LABBY areas. Use a fan off-delay after powerdown for cond. prevention.

Interested? Do it yourself ;D ;D ;D ;D :eek: :cool:

COOL LASERS ARE HOT :cool:

Cheers [smiley=beer.gif]
 

Daedal

New member
Joined
May 23, 2007
Messages
2,277
Points
0
Laserrod said:
IDEA:
TEC cool the LASER/AXIZ/LENS real cold. Then to combat the lens frosting use a output
aperture tube, let's say 1" long and butted up against the output lens; then blow disicanted air(moisture free) into the tube by useing bypass air presure from the TEC cooling fan filtered through baked epsom salt (or equiv.) media screened canister then directed into the aperture tube. Canister must be easly replaceable. Rebaked in MW oven to boil moisture out.
Waterproof appropriate LABBY areas. Use a fan off-delay after powerdown for cond. prevention.
Or try running it on the north/south pole ;) It's so dry there and so cold... the diode would be in heaven ;D And when it gets dark it stays dark for a while, so you can test your results right away... ;)

--DDL
 

laserrod

New member
Joined
Aug 3, 2007
Messages
342
Points
0
DDL,
If things get any worse in our Homeland, I'll be heading for the southern pole to cool off and be free of those pesky "terrorwist" ;D (Elmer Fudd will protect us ;D)

Shine on you crazy diamond(laser beam combiner) :cool: (Pink Floyd exerpts)

Cheers [smiley=beer.gif]
 

laserrod

New member
Joined
Aug 3, 2007
Messages
342
Points
0
Enclose the whole labby as I discribed(w/o tube blower); in a large disicated airtite enclosure to avoid that pesky water cond. The output lens will need to be heated because it's too close to cold stuff.

Put the labby in a big coffee can. Large area disipates all the heat inside.

;D ;D ;D ;D

That sounds easier :D

I'm inspired now!

Cheers [smiley=beer.gif]

Level 2 at 50 ;D
 




Top