Laser pointer discussion. Read/write reviews of laser pointers and laser pointer companies. Learn about all types of laser pointers and lasers





Welcome to Laser Pointer Forums! If you are looking for a laser pointer or want to compare different laser pointer companies, you may want to check out the LPF Laser Pointer Company Database. The link will open in a new window for your convenience.








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes
Laser Technology Laser Pointer Parts Lasers by Wavelength
Top 10 Laser Pointer Companies Laser Pointer Company Database Visible Beam Laser Pointers


One laser store meets all your needs

























Go Back   Laser Pointer Forums - Discuss Laser Pointers > Lasers > Blue, Yellow, & Other Colored Lasers



LPF List of Laser Pointer Companies (link opens new window)



Reply
 
LinkBack Thread Tools Display Modes
Old 11-02-2014, 05:41 AM #1
Alaskan's Avatar
Class 4 Laser
 
Join Date: Jan 2014
Location: Currently in Iraq.
Posts: 7,107
Rep Power: 50005
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Alaskan Alaskan is offline
Class 4 Laser
Alaskan's Avatar
 
Join Date: Jan 2014
Location: Currently in Iraq.
Posts: 7,107
Rep Power: 50005
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Default How much is too much current for C-Mount IR?

Hello,

Has anyone here taken a C-mount 808nm laser diode and overdriven it much? I have one rated to 4.4 amps 4 watts CW and want to push it to 6 amps. Would that likely kill it or substantially shorten its normal life?



Why? Mo-green power! Sharing the story for those who might have dead high power pointers and want to do something similar:

I recently took a 250mw 532nm laser pointer I've had for three years which was advertised on aliexpress to be 2 watts (I think I paid 250 for it):



50000mw green laser pen on Aliexpress.com | China laser sellers often LIE stating outputs several times higher than reality

...and put the battery in backwards, killing it, stupid to design it that way, a blocking diode would have prevented the problem - Moving forward after murdering my pointer and checking its C-mount 808nm laser diode, I found it was still good, but the driver toast, the parts for it wiped of identifying markings. Instead of trying to find another high current driver to fit or toil trying to determine the unmarked parts to fix it, I modified it some (extreme understatement), removed the 2.5 watt (output measured at 2 VDC) IR diode and replaced it with a FAC lensed C-mount 4 watt laser diode, remounting it in one of these:



808nm Housing Case Mount for Laser Diode C Mount Good Cooling | eBay

Fortunately, the part of the laser pointers head (inside part, now removed) which has the vandate and ktp crystal inside it had the right OD size to fit into the above laser host so it could take heat away from it. However I couldn't use the original section of the pointer which contained the C-Mount laser diode because it's OD didn't match the new host, but the new hosts C-mount section fit together with it fine.

After putting the thing together the new hosts lens wasn't right (expected), I couldn't focus, so I had to remove the concave-concave expander lens from the output of the laser module to reduce the beam width to something easier to adapt to the optics I had on hand. However, after removing the concave lens I was pleased to find I didn't need to find another collimating lens because the one which came with it would then make a tight enough beam, but at increased divergence, a problem I intended to solve using a telescope.

Testing, I pushed the IR diode above its 4.4 rating to 5 amps and was able to get about 550mw out, now I'm cooking with green ...maybe risking the laser crystals inside but no failure yet! Adding a 8X beam expander I recently bought on ebay (thank you electronic badger for the link) the divergence was then taimed and what a beautiful beam it puts out, the divergence appears to be low now and I can put a bright green spot on the underside of clouds at night

Expander:



However, not willing to leave good enough alone, I'm wondering, how hard can a 808nm laser diode rated for 4.4 amps of CW output be driven without shortening it's life too much? I mean, I probably won't put a whole lot of time on this laser pointer over the years, so if it's life is reduced to 50 hours, that's probably more than 2 life times worth for me. Any idea if I can drive it to 6 amps very safely? Next, I will be crying I fried my ktp crystal, I know, but wondering.

Oh, I might as well add, I'm now driving the unit with a pack of size C alkaline batteries and this voltage regulator:

http://www.ebay.com/itm/LED-DISPLAY-...-/161051476129

It is not constant current, but I can watch the amount of current draw to keep an eye on it, so far, the diode is behaving and not drawing additional current when it warms up (very little, anyway).

My 550mw ghetto pointer:



Nevermind the 2.4 volts shown on the regulator, the power leads to the diode are small, a bit of voltage drop there.

Next is to have a host built so that everything can fit into it and a constant current regulator.


__________________

The forum costs more to run than donations received, if you wish to help click this link: http://laserpointerforums.com/donations.htm

Laser Safety: http://www.laserpointersafety.com/index.html

Sam's Laser FAQ: Sam's Laser FAQ: Welcome Page

RHD's Relative Perceived Brightness Calculator. Compare brightness @nm: http://lsrtools.1apps.com/relativebrightness

To shorten my signature I have moved most of my laser related web links to this forum page, the second post in that thread shows most of my builds... Alaskan's Laser Links: http://laserpointerforums.com/f44/al...ml#post1449395


Sincerely investigate any of these three short quotes as new concepts and you've taken your first step into a larger world:

"I regard consciousness as fundamental. I regard matter as derivative from consciousness..." - Max Planck. "Everything we call real is made of things that cannot be regarded as real" - Neils Bohr. "What we call physical things and events do not exist independently of subjective experience..." - Deepak Chopra.

Each of these three rabbit holes go deep, ending up in the same place.

Useless troll fighting.
.........................
PhotoB****t high jacking you too? Use this link instead:
http://imgbb.com

High resolution of my avatar: https://ibb.co/fWOhXF

Last edited by Alaskan; 11-03-2014 at 03:35 AM.
Alaskan is offline   Reply With Quote







LPF List of Laser Pointer Companies (link opens new window)







Old 02-03-2015, 04:02 PM #2
Junior Member
 
Join Date: Sep 2014
Posts: 1
Rep Power: 0
anomalytech is on a distinguished road
anomalytech anomalytech is offline
Junior Member
 
Join Date: Sep 2014
Posts: 1
Rep Power: 0
anomalytech is on a distinguished road
Default Re: How much is too much current for C-Mount IR?

Hey,

Awesome ghetto pointer! I cannot believe no one has responded to this! I will chip in my $0.02 for what it's worth. I haven't done very much experimentation with C-mount diodes, I've only worked with a 500mW rated 808nm C-mount. The beauty of these IR C-mounts is their fairly large to massive emitter sizes. This is very bad when it comes to collimation (and requires an FAC to do so apparently), but is a blessing in disguise when overdriving. I personally think your C-mount will easily handle 6 amps for a few reasons. Since the diode's design current is already 4.4A, you're only increasing the current by 36%. Compared to most other overdriving scenarios(which can sometimes exceed 200%), this will most likely be a walk in the park for your diode. The other reason is the emitter size, it has a lot more area to be pumping out that 808nm, so you are less likely to see a catastrophic optical destruction occur, especially for such a small current increase. (Keep in mind, it was MEANT to run 4.4 amps for potentially hours on end)

I know it has been a while since you've posted, but I just wanted to chip in just in case the ghetto saber is waiting to be awoken. I'll be doing some more C-mount testing soon, and see just how far these 808 diodes can go.

--Max
anomalytech is offline   Reply With Quote
Old 02-21-2015, 06:27 AM #3
AgentMcBaine's Avatar
Class 2 Laser
 
Join Date: May 2012
Location: Dyer, Indiana, US
Posts: 293
Rep Power: 205
AgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond repute
AgentMcBaine AgentMcBaine is offline
Class 2 Laser
AgentMcBaine's Avatar
 
Join Date: May 2012
Location: Dyer, Indiana, US
Posts: 293
Rep Power: 205
AgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond reputeAgentMcBaine has a reputation beyond repute
Default Re: How much is too much current for C-Mount IR?

Don't cross the streams with that. Could be dangerous
How much is too much current for C-Mount IR?-str2_cn_2404_ghostbusters_a.jpg
AgentMcBaine is offline   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On











Loading








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes






Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 01:53 AM.


Powered by: vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC