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Is a heatsink needed for a 1.8 driver?

Pluxx

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Ok so i've started working on a new laser. Its a 445nm using the M-type m140 Module. However the problem is i dont know how many amps my driver should be and what is the maximum i can do without heatsinking the driver. I want to go for a 1.8 A driver as shown below however am not sure if it needs heatsinking so back when i made my older laser with the A-type M140 module i used a 1.5A. So my question is can i use a 1.8A driver with this diode? also can i oush it further maybe up to 2 Amps and answer will be appriciated thanks! :yh::yh::yh:

This is the driver im planning on buying:

Survival Laser Driver
 

Pi R Squared

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No you can't go up to 2A with an M140, 1.8A is the maximum. Anything from 1.25-1.8A is normal, mine is driven at 1.5A. That driver is very efficient and doesn't need heat sinking, your diode will overheat before the driver would, as long as you observe a proper duty cycle then there is no problem, most any driver up to 1.8A doesn't need heat sinking, and anything over 1.8A should be heat sinked.

Alan
 

olympus mons

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It's my understanding that heat sinking 1.8A and less actually will stop the driver from cooling off and hold more heat than it sinks.
 

Pman

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I never heard that before nm. It sounds reasonable though.
I started heat-sinking all drivers about 6 months ago because I figured it wouldn't hurt. Is that from actual tests someone has done? It must be talking specifically about that particular driver as there's no way that makes sense otherwise.
 

APEX1

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It's my understanding that heat sinking 1.8A and less actually will stop the driver from cooling off and hold more heat than it sinks.
There is no need for heatsinking for what he's trying to do. However if your using a crappy driver it might be needed!
 

Pluxx

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No you can't go up to 2A with an M140, 1.8A is the maximum. Anything from 1.25-1.8A is normal, mine is driven at 1.5A. That driver is very efficient and doesn't need heat sinking, your diode will overheat before the driver would, as long as you observe a proper duty cycle then there is no problem, most any driver up to 1.8A doesn't need heat sinking, and anything over 1.8A should be heat sinked.

Alan
So just to make sure i can use the 1.8A driver without a heatsink correct?
 

Pluxx

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Yes that's correct.

Alan
Thanks a lot. Also i hope im not annoying you with anything or so but is there an equation as to how you calculate the output power of the diode? Andwill this laser go over 2W if i use the 1.8A driver?
 

Pi R Squared

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Thanks a lot. Also i hope im not annoying you with anything or so but is there an equation as to how you calculate the output power of the diode? Andwill this laser go over 2W if i use the 1.8A driver?
No you can't calculate the output, the efficiency of each diode will vary, also the lens you use will make a difference. You must use a laser power meter to determine output, however an M140 at 1.8A and a G2 or other single element lens should give you 2 - 2.3W.

Alan
 

olympus mons

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I never heard that before nm. It sounds reasonable though.
I started heat-sinking all drivers about 6 months ago because I figured it wouldn't hurt. Is that from actual tests someone has done? It must be talking specifically about that particular driver as there's no way that makes sense otherwise.
Yeah it makes sense when you think about it. DTR explained that under 1.8 the driver doesn't create enough heat to cause damage so when you heat sink it, it extends your off duty cycle because it takes longer to cool. I would guess if you could make solid contact with the host body with. Heat sink that would be different. But not necessary.
 

Pi R Squared

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I just remembered, one of my lasers has a 2.2A Survival Laser driver that isn't heat sinked and it has been workin fine for 2 years now, but the duty cycle is only about 35 seconds, I had it on over a minute once and it got too hot, but I don't think that's long enough for the driver to overheat.

Alan
 




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