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 > Experiments & Modifications



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



Reply
 
LinkBack Thread Tools Display Modes
Old 07-04-2008, 01:01 AM #1
Class 1 Laser
 
Join Date: Apr 2009
Posts: 98
Rep Power: 9
LikeitBright will become famous soon enough
LikeitBright LikeitBright is offline
Class 1 Laser
 
Join Date: Apr 2009
Posts: 98
Rep Power: 9
LikeitBright will become famous soon enough
Default Driving laser diodes in parallel?

Just curious, has any one driven several (2 or more) laser diodes in parallel using just the one driver? Any problems or issues that cropped up? Perhap the current limiting wouldn't work so well here and a separate driver is needed for each LD?


LikeitBright is offline   Reply With Quote







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







Old 07-04-2008, 03:02 PM #2
rkcstr's Avatar
Class 3R Laser
 
Join Date: Dec 2007
Posts: 1,368
Rep Power: 142
rkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond repute
rkcstr rkcstr is offline
Class 3R Laser
rkcstr's Avatar
 
Join Date: Dec 2007
Posts: 1,368
Rep Power: 142
rkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond reputerkcstr has a reputation beyond repute
Default Re: Driving laser diodes in parallel?

Quote:
Originally Posted by LikeitBright
Just curious, has any one driven several (2 or more) laser diodes in parallel using just the one driver? *Any problems or issues that cropped up? Perhap the current limiting wouldn't work so well here and a separate driver is needed for each LD?
In parallel, the voltage output of the driver would be the same, but the current would be split between the diodes. It would be ideally split equally with similar diodes, but depends on the apparent resistance of each. So, if you wanted to drive two diodes at 300mA, your driver would have to put out 600mA.

You could also do them in series, but the output voltage will be doubled, while the output current will be the same through both, or equivalent to the output current of the driver.

I personally haven't tried, so I don't know if there are any problems with doing this, as I'm just going on theory. But, if you want to be the guinea pig, go for it ;D
__________________
Laser drivers and Test Loads - rkcstr.com

Enter discount code "LPF" during checkout to save 10% off of the regular prices!
rkcstr is offline   Reply With Quote
Old 07-04-2008, 05:28 PM #3
FireMyLaser's Avatar
Class 3B Laser
 
Join Date: Jan 2008
Location: Sweden
Posts: 3,052
Rep Power: 567
FireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond repute
Send a message via MSN to FireMyLaser
FireMyLaser FireMyLaser is online now
Class 3B Laser
FireMyLaser's Avatar
 
Join Date: Jan 2008
Location: Sweden
Posts: 3,052
Rep Power: 567
FireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond reputeFireMyLaser has a reputation beyond repute
Send a message via MSN to FireMyLaser
Default Re: Driving laser diodes in parallel?

I think it's a bad idea. The current will choose the path with the least resistance and the diodes aren't completely identical. Some might work at 3.0V or 2.8V or 3.1V etc. So if you conect two (or more) diodes in parallel, so will the one with the lowest voltage get most of the current. For example: one will only get 200mA and the other will get 400mA (600mA total). The diode with the highest current will soon die, and when it does will the other diode get 600 mA and die in an instant.

That's why parallel is bad and series is good because the current is the same anywhere in the circuit. Or use two drivers.
__________________
Niko likes cereal.
FireMyLaser is online now   Reply With Quote
Old 07-04-2008, 10:21 PM #4
Class 1 Laser
 
Join Date: Apr 2009
Posts: 98
Rep Power: 9
LikeitBright will become famous soon enough
LikeitBright LikeitBright is offline
Class 1 Laser
 
Join Date: Apr 2009
Posts: 98
Rep Power: 9
LikeitBright will become famous soon enough
Default Re: Driving laser diodes in parallel?

Yes, I agree on the theory - its the practical downside that may come back to bite me I'm thinking of

My main concern is the unequal current issue which is why series is starting to sound better at this point. Then again, a micro-drive for each module will cost $70 total so thats not too bad.
LikeitBright is offline   Reply With Quote
Old 07-05-2008, 01:59 AM #5
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
nikokapo nikokapo is offline
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
Default Re: Driving laser diodes in parallel?

Quote:
Originally Posted by FireMyLaser
I think it's a bad idea. The current will choose the path with the least resistance and the diodes aren't completely identical. Some might work at 3.0V or 2.8V or 3.1V etc. So if you conect two (or more) diodes in parallel, so will the one with the lowest voltage get most of the current. For example: one will only get 200mA and the other will get 400mA (600mA total). The diode with the highest current will soon die, and when it does will the other diode get 600 mA and die in an instant.

That's why parallel is bad and series is good because the current is the same anywhere in the circuit. Or use two drivers.

Agreed.



If they were two equal diodes i'd try it, but not with different diodes that need different currents.
nikokapo 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 06:45 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