after recharging the batteries my diode blow-up

[BoskoSLO]

The size of the heatsink and grade of its material effects how well of a buffer it acts as though. it also effects how quickly it can move the heat and how much it can store. Generally from my exp is the actual heat dissipation of the host is generally far too low to properly cool the heatsink and diode. Which is why we much duty cycle them as the heatsink will slowly gather more heat until it becomes too hot and you must turn it off and let the heat dissipation ability of the host catch up. So going with this I would say the heatsink volume matters a ton since the bigger and more heat it can store and the longer you can run your laser at a time.

Not trying to contradict you Blord, its only my opinion based off my observations.

well, yes this makes sense.

I saw your sig:
http://laserpointerforums.com/f39/n...-black-ice-lasers-free-us-shipping-79069.html

and u wrote that the Approximate Suggested Duty Cycle is:
1-1.3W = 120 seconds on 30 seconds off
1.4-1.6W = 90 seconds on 30 seconds off
1.7-2W+ = 90 seconds on 45 seconds off
*Lower runtimes will result in longer diode life*

Its quite long for me. two weeks ago when my DVD red laser diode was still working the host and the small heatsink heat up very quickly. Like after 20sec it got too hot for my sense. But ~1.9W blue laser with this heatsink?
Looks like blue LD produce less heat that red LD?.

I searched not long time ago and found this heatsink:

bolha.com :: Hladilnik Intel socket LGA 775 (Core 2 Duo, Core 2 Quad)

the core of the heatsink is "full" copper sorounded with aluminium fins.
this may be the perfect heatsink

 

[ApexProxy]

The heatsinks I use aren't actually all that small but size is relative of course. Its also possible you were way over driving the diode which causes them to produce more heat with little to no extra output or even less output.

CPU heatsinks work amazingly as laser heatsinks since even the smallest ones are designed to cool 80W+ and even 2W 445nm lasers only run at 8-10W.

 

[Th3dArKn3o]

The size of the heatsink and grade of its material effects how well of a buffer it acts as though. it also effects how quickly it can move the heat and how much it can store. Generally from my exp is the actual heat dissipation of the host is generally far too low to properly cool the heatsink and diode. Which is why we much duty cycle them as the heatsink will slowly gather more heat until it becomes too hot and you must turn it off and let the heat dissipation ability of the host catch up. So going with this I would say the heatsink volume matters a ton since the bigger and more heat it can store and the longer you can run your laser at a time.

Not trying to contradict you Blord, its only my opinion based off my observations.

There are two types of heatsink: A big massive heatsink who only soaks all the heat up until the complete heatsink is hot and then you need to cool down before you fry the diode !
The Other Type which I like much more is one with the capability to heat vent itself I used that kind of heatsink in my 2,5W Build and I have an continuous duty cycle on that Laser

 

[ApexProxy]

Heatsinks capable of dissipating enough heat for continuous duty cycle tend to be larger than desired for handheld and also need to be well finned to increase their surface area and for smaller size active cooling can be used. For most typical pointer builds the heat generation is greater than the dissipation capability simply due to size constraints. A CPU cooler like mentioned above would be a bench cooler or a very large handheld unit that would give infinite duty cycle but is far larger than most people desire for a portable laser.

The heatsink BoskoSLO made is a standard pointer style heatsink that will have a duty cycle unless the host has rather large fins on it or quite a bit is added to the heatsink..

 

[Th3dArKn3o]

My 2,5W Full Custom Build is something between bench labby and portable

 

[ApexProxy]

Haha yup that's what I was saying. Its cool though I have a bench laser planned myself except I will be using a TEC unit and a very large Zalman cooler so I should have no issues hitting very very high output (~3.5-4W) with the 9mm 445nm diode I will be using.

 

[Th3dArKn3o]

Yeah that is definitely cool though I haven't much need for a bench laser I like my lasers portable and handheld If I need a Lab I use my vice on one of my Lasers

 

[darkmagic89]

A safe current for the LPC 826 is 350mA and 400mA max with good heat sinking !
I'm sure the diodes of old 16xDVD Burners are not the LPC 826 !
Just order a LPC 826 to be sure you're getting the right diode

not to be rude, but i have the LPC-826 LD from odicforce's ebay shop and use it continuesly for around 15 minutes at 2 different current level, first one at 330mA and the second one at 610mA (i have video proof about this) ,it is true that it became very hot (the aixis module) in the first minutes of use,but did not die for short period of time (by gripping the module whit my bare fingers act like a lite "liquid cooling sistem" because of blood flowing and exchanging temperature. (now have died because i forgot it on for an entire night at 610mA, my fault )

the driver i was using was a double driver in variable constant voltage and costant current regulator made whit 2 LM317.

hope this wold help and please excuse my bad english

Alex