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

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

overcurrenting a led

V

vari

0
Joined
Nov 24, 2011
Messages
38
Points
0
Is there some consensus over how overcurrenting a led affects it's lifespan (and brightness)?

I have a resistor to choose for my led driver that defines the current, and the specification is 1.5-1.8A for the led. I have plenty of heatsinking so the led will run at ambient temperature. Should i settle for 1.8A or can i safely bump that to say 2-3A?

I know laser diodes are sometimes run with up to 100% overcurrent succesfully for extended periods of time. Do leds behave the same?
 





lasersbee

lasersbee

0
Joined
Sep 20, 2008
Messages
17,622
Points
113
Think of applying more that 120Vac to a standard 120Vac Light bulb.
The higher the voltage across the light bulb the more its life will
decrease while the brightness goes up until it blows...

Jerry
 
Cyparagon

Cyparagon

0
Joined
Sep 12, 2007
Messages
9,399
Points
113
The light output with respect to current is not as linear with LEDs as it is with laser diodes. Increasing the current that much above max will not increase the light output too much. Assuming it doesn't blow right away if you drive it that hard, it will slowly dim down to nothing over the next few days

I prefer to run (chinese off-brand) LEDs at no more than 60% their rated current.
 
rhd

rhd

0
Joined
Dec 7, 2010
Messages
8,475
Points
0
Cyparagon said:
I prefer to run (chinese off-brand) LEDs at no more than 60% their rated current.
Click to expand...

I've had the same experience with chinese-off-brand LED emitter "plates". Running them at around 70% of their rating produced an amount of light almost indistinguishable from running them at their actual rating. Running them higher than their rating was a negative return.

Something like an SST-90 might be a different story.

What model LED is this?
 
S

saabluster

0
Joined
Nov 9, 2011
Messages
8
Points
3
vari said:
Is there some consensus over how overcurrenting a led affects it's lifespan (and brightness)?

I have a resistor to choose for my led driver that defines the current, and the specification is 1.5-1.8A for the led. I have plenty of heatsinking so the led will run at ambient temperature. Should i settle for 1.8A or can i safely bump that to say 2-3A?

I know laser diodes are sometimes run with up to 100% overcurrent succesfully for extended periods of time. Do leds behave the same?
Click to expand...

No way to answer your question without knowing what kind of LED you have. And what is "plenty of heatsinking"? Are you using an mcpcb?
 
BShanahan14rulz

BShanahan14rulz

0
Joined
Dec 29, 2009
Messages
3,136
Points
63
vari said:
Is there some consensus over how overcurrenting a led affects it's lifespan (and brightness)?
Click to expand...

Yes, it affects lifespan negatively and brightness positively

vari said:
I have a resistor to choose for my led driver that defines the current, and the specification is 1.5-1.8A for the led. I have plenty of heatsinking so the led will run at ambient temperature. Should i settle for 1.8A or can i safely bump that to say 2-3A?
Click to expand...
That depends on the LED and how much and how efficient your heatsinking is.

vari said:
I know laser diodes are sometimes run with up to 100% overcurrent succesfully for extended periods of time. Do leds behave the same?
Click to expand...

Again, it depends. Some makers are better at making LEDs than others, and there are many more "generic" LEDs than there are laser diodes.

What kind of LED is it, and what kind of heatsinking are you providing it?
 
You must log in or register to reply here.




Top