Difference between Luxeon and Luxeon Star LED's?

sygyzy

Enlightened
Joined
Jan 29, 2003
Messages
749
Difference between Luxeon and Luxeon Star LED\'s?

I know that the star obviously has a "pcb" that looks like a star. How do the different shapes affect the decision as to which is used in flashlights? For example, could every flashlight that takes a regular Luxeon use a star? What about in homemade flashlight mods? Can you put a star on a hotlips and put that in a Mag? There has to be some reason Lumileds invented the Star design other than just for looks.
 

idleprocess

Flashaholic
Joined
Feb 29, 2004
Messages
7,197
Location
decamped
Re: Difference between Luxeon and Luxeon Star LED\'

Luxeon Stars are large and cumbersome for small flashlight mods, but arguably more convenient for the novice electronic tech to work with.

As to why there are stars and emitters... The star is a convenient building block for larger applications where space isn't at a premium, or you're not using automated board-stuffing equipment to load up your PCB. Emitters are good for small applications (such a flashlights), or any application where the designer will take total responsibility for heatsinking, or needs better thermal performance than LED->star->heatsink.

Any Luxeon Star LED can be safely operated for short periods of time without external heatsinking. Some 1-watt LS applications don't require external heatsinking due to low operating currents or good thermal design. Operating Luxeon emitters without an external heatsink will let out the magic smoke in short order.

I have personally fried a LuxV white emitter that I thought was secured to its heatsink (an absurdly large finned aluminum extrusion) - but later found that it had started to seperate EVER SO SLIGHTLY from the heatsink.
 

idleprocess

Flashaholic
Joined
Feb 29, 2004
Messages
7,197
Location
decamped
Re: Difference between Luxeon and Luxeon Star LED\'

Also - the different flavors of stars are for different needs. There are two styles with built-in connectors (AMP and IDC styles). The /O star has built-in optics to focus the output into a narrow beam.
 

kitelights

Flashlight Enthusiast
Joined
Jun 8, 2002
Messages
1,377
Location
Richmond, VA
Re: Difference between Luxeon and Luxeon Star LED\'

The "pcb" star is a metal heatsink. Most applications use the emitter only (the LED without the star) although some do use the emitter on the star. From what I understand, in the instances where a star is used and screws are used for installation, the stars can very easily be swapped out.

The stars are not used as often because of their larger diameter and usually a better, more efficient heatsink is used in its place.
 

Klaus

Flashlight Enthusiast
Joined
Sep 6, 2001
Messages
1,998
Location
Germany
Re: Difference between Luxeon and Luxeon Star LED\'

From a buyers point of view its nice that you always have the binning printed on the back of the star which is quite convinient - with emitters only the reel is marked and you never know what you have on hand when buying smaller quantities - except when buying from known good sources on CPF where I believe this shoudn´t be any problem.

From the user perspective is not a biggie to remove the emitter from the star in case you need just the single emitter only for your mod - doing hundreds of mods it could get tiring though /ubbthreads/images/graemlins/grin.gif

From a tinkerers perspective its much easier to damage the leads on an emitter when doing multiple on/off soldering operations - this is quite cake with the stars though.

In the end I personally would always prefer to BUY stars while for the raw USE with ARC/SF/MAG mods I prefer emitters

YMMV

Klaus
 

sygyzy

Enlightened
Joined
Jan 29, 2003
Messages
749
Followups

Well the answers I am surprised to find are not really any different than I thought. I am curious why stars are mentioned at all because really, are there any homebrewed custom mods that are using stars? Like everyone says, even if space permitted their use, the preferred method is to have the emitter on a larger heatsink.

Are there any light mods that use the star without mods? Also, where do you connect the positive and negative on a star? On a plain emitter there are just two nubs so it's easy to figure out.
 

WildRice

Flashlight Enthusiast
Joined
Nov 30, 2003
Messages
1,135
Location
SW Michigan
Re: Followups

all the stars I had have small (-) and (+) marked near the solder pads.
Jeff
 
Top