Will 1300mA Current Output blow a Q5-WC

[how2]

Hi I'm new would like to know the

I see two flash lights on DX SKU 28545 NKoray K109 and SKU 16844 Ultrafire A1 they both use Q5-WC led one is regulated at 1300mA and the other 1000mA. Had a look at Cree data sheet http://www.cree.com/products/pdf/XLamp7090XR-E.pdf.

It states the


Maximum drive current: up to 1000 mA Will the LED on the NKoray k109 not blow?

Thank you

 

[radu1976]

I was told that if you are using them for short periouds - 10 min - it shouldn't be a problem.

I didn't have any pb so far with my DEREELIGHT CL1H and JETBEAM III PRO IBS , both driven at 1.2A.
Also, it's said that if the light has a good heatsinking - as the lights mentioned above - there shouldn't be any issues when the emitter is driven a bit over 1A

I am not a specialist at all but this is what I have read.

 

[Gunner12]

There shouldn't be a problem if the LED is heatsinked correctly.

The XR-E has been pushed to over 2 amps and has survived without a problem, but that requires a larger heatsink. 1.3 amps shouldn't be much of a problem.

 

[Tekno_Cowboy]

I've seen them driven at 1.4A with no problems, with proper heatsinking. With a Cool emitter it's not so much of a problem, but I've also noticed a tint shift when overdriving a Neutral/Warm LED.

 

[bigchelis]

It should be fine.

I have two 18650 DX lights lipstick type. They have R2 emitters and krammer5150 put 1.4A drivers in each of them. I have used them for hours at a time with my laptop 18650 recyled cells succesfully.

Please note that with the laptop cells the current at the tail is 1A, but when I put IMR 18650 cells It stays put at 1.39A.

My guess is I haven't had issues because I use the cells that keep the current lower, which is okay for me since I use two of them at a each side of my head in a Fenix headband for over an hour at a time.

 

[kramer5150]

As others have noted... it depends on a variety of factors:

-How long the light is left ON.
-The ambient conditions surrounding the light while ON.
-Thermal cooling capabilities of the host.
-Current delivering capabilities of the cell used.

If your light is optimized for all the above and you are not using IMR cells, it will be just fine.

If you are using a small, pocket-EDC capable light with an IMR cell, I would keep an eye on the light, limit ON cycles to 5-6 minutes at a time, and make sure you keep cool air circulating around it. It may not fry the LED instantly, but you may have shortened the LED lifespan unknowingly.

 

[mudman cj]

I've seen them driven at 1.4A with no problems, with proper heatsinking. With a Cool emitter it's not so much of a problem, but I've also noticed a tint shift when overdriving a Neutral/Warm LED.

Keep in mind that overdriving a neutral/warm emitter at 1.4A is not the same thing as overdriving a cool white emitter at 1.4A. The upper spec for neutral/warm emitters is 700mA because a larger proportion of the drive power is converted to heat by the phosphors compared to cool white, in which more of the primary light is emitted without being converted. In this context, I used the term primary to refer to the light created by the LED junction, which is blue for this type of LED.

So using simple ratios, a 1.4A overdrive of a cool white emitter is approximately equivalent to a (1.4/1)*.7 = 980mA drive current of a neutral white/warm white emitter. Similarly, a 1.4A drive current of a neutral white/warm white emitter is approximately equivalent to a 2A drive current for a cool white LED.

As has been noted, they can survive at this level if well heat-sinked, but the phospors themselves overheat and their emission characteristics change. In addition, the high temperatures cause degradation of the phosphors that will eventually impact their behavior at drive currents within spec as well.

 

[kramer5150]

Keep in mind that overdriving a neutral/warm emitter at 1.4A is not the same thing as overdriving a cool white emitter at 1.4A. The upper spec for neutral/warm emitters is 700mA because a larger proportion of the drive power is converted to heat by the phosphors compared to cool white, in which more of the primary light is emitted without being converted. In this context, I used the term primary to refer to the light created by the LED junction, which is blue for this type of LED.

So using simple ratios, a 1.4A overdrive of a cool white emitter is approximately equivalent to a (1.4/1)*.7 = 980mA drive current of a neutral white/warm white emitter. Similarly, a 1.4A drive current of a neutral white/warm white emitter is approximately equivalent to a 2A drive current for a cool white LED.

As has been noted, they can survive at this level if well heat-sinked, but the phospors themselves overheat and their emission characteristics change. In addition, the high temperatures cause degradation of the phosphors that will eventually impact their behavior at drive currents within spec as well.

thats good to know... I was unaware, thanks

 

[LEDAdd1ct]

Wow, an amazingly well-stated summary. Thank you!