Seoul P4 and 1000mA buckpuck

[MoonDragn]

Hi Guys,

I may not be right about this but it sounds to me like maybe there is some kind of contact with the LED wire up and the heatsink causing some type of short but still being able to light up the LED. DC voltage has a tendency to heat up metal quickly when shorted out. I could be wrong but it might be possible.

To generate that kind of heat, it would have burned out that short a long time ago. It could be possible that these P4 LEDs he got are defective, and cannot really take the currents rated?

Have you tried to use a lower current buckpuck? Say 350 mA or 700 mA one and see if it gets too hot?

[Jedi-Diah]

If the problem only happens with the P4 with identical setup as the Lux III (same batteries, same heatsink, same buckpuck), then yes, the problem is only with the P4. Must be defective. That is way too hot. Most people have not heat issues at all (like the Lux III).

I do. I have a lux 3 green and a lux 3 red. Both are using copper heatsinks. No trouble whatsoever.

I did however try this for the first time. I put the P4 on the copper heatsink, then put it inside my MHS saber hilt. Took a longer amount of time, but the hilt got so hot that I was not able to touch the handle it was so hot after about 90 seconds. When I took the Hilt back apart, the little legs that hold the lense holder on the LED star, melted off. It took me 30 minutes just to clean all the melted plastic and super glue off the LED and heatsink. At this point, I'm really beginning to think, the $8 LED is not worth the trouble of burning my fingers and ruining parts to try to get it to work.

[JediKnightBJ]

To generate that kind of heat, it would have burned out that short a long time ago. It could be possible that these P4 LEDs he got are defective, and cannot really take the currents rated?

Have you tried to use a lower current buckpuck? Say 350 mA or 700 mA one and see if it gets too hot?

Nope, don't have a lower power buck puck. I have an adjustable current supply at work. I can set the voltage and current separately. I set the current at 350ma, and the voltage at 3.29v(closest to 3.25v i can get) and it gets hot, but not burning hot.

I tried it at 700ma, it gets burning not, not melty plastic hot, but melting hot glue, burn fingers hot.

[Jedi-Diah]

Hi Jedi Knight BJ,

Does the LED look like its working fine otherwise (as far as brightness goes)?

Nope, don't have a lower power buck puck. I have an adjustable current supply at work. I can set the voltage and current separately. I set the current at 350ma, and the voltage at 3.29v(closest to 3.25v i can get) and it gets hot, but not burning hot.

I tried it at 700ma, it gets burning not, not melty plastic hot, but melting hot glue, burn fingers hot.

[MoonDragn]

Nope, don't have a lower power buck puck. I have an adjustable current supply at work. I can set the voltage and current separately. I set the current at 350ma, and the voltage at 3.29v(closest to 3.25v i can get) and it gets hot, but not burning hot.

I tried it at 700ma, it gets burning not, not melty plastic hot, but melting hot glue, burn fingers hot.

It really sounds to me like they are either defective or theres two versions of the P4 and you got the version thats rated at 350 mA and not 1000 mA. You really want to run the P4 at 350 mA though. Thats when they are at maximum efficiency. That means it would last a lifetime. If you run it at 1000 mA it will burn out. The amount of lumens the P4 puts out at 350 mA is comparable to a Luxeon at 700 mA.

[Jedi-Diah]

Whether or not you will get longer life from the LED or longer battery run time is not the issue. The P4 is rated to handle "up to" 1000mA and most people do without any kind of heat issues.

It really sounds to me like they are either defective or theres two versions of the P4 and you got the version thats rated at 350 mA and not 1000 mA. You really want to run the P4 at 350 mA though. Thats when they are at maximum efficiency. That means it would last a lifetime. If you run it at 1000 mA it will burn out. The amount of lumens the P4 puts out at 350 mA is comparable to a Luxeon at 700 mA.

[MoonDragn]

Whether or not you will get longer life from the LED or longer battery run time is not the issue. The P4 is rated to handle "up to" 1000mA and most people do without any kind of heat issues.

Thats why I think either he has a defective LED or a slightly different version of one.

[Jedi-Diah]

My guess is also the LED is bad. What else could it be?

As far as I can tell, there is only one version of the P4 (3.5W) and it is rated mA typ: 350-1000mA, mA max: 1000mA. Whereas the Seoul 1W is rated only at 350mA (the 2W is rated at 700mA).

http://www.led-tech.de/en/High-Power...-c_121_78.html

There is an interesting sentence under the description under "Please Note":
"The low forward voltages (Vf) assure a low development of heat that benefits a maximum live time of the products."

But also from the spec sheet it warns:

"When the LEDs are illuminating, operating current should be decided after considering the package maximum temperature."

Thats why I think either he has a defective LED or a slightly different version of one.

[Strydur]

I would say LED as well. The last batch I got had 6 that did not even light up. Now I know why I put off stocking P4's for so long. We have never had a issue with a luxeon LED. But then again many people have been fine with them so maybe I just got a bad batch. Problem is its a pain in the arse to get them let alone return a bad one.

[JediKnightBJ]

Well, I'm just trying to figure out where to go from here. Tim, you are awesome, and I don't want to be a pain to you, but I know I can't use this LED.