2watt 445nm build questions

[dubious speculation]

Hey everyone,

As some of you may know I'm currently in the process of building a C2 445 2W+ build. I have a few questions about the build and in particular the host, my main goal is to achieve a 2watt output with an m140 with a decent duty cycle

So for the host I can't decide between the c6 or the c2 host, the only reason im leaning towards the c2 is to achieve a better duty cycle, here's the c2 host

Ultrafire C2 DIY Cree LED Flashlight Shell/Casing Complete Set with Driver Pill (1*18650/2*CR123A) - Free Shipping - DealExtreme

What I'm wondering is that will the c2 host with aluminium heatsink provide a better duty cycle over a c6 with a copper heatsink? currently cliff has an awesome price on c6 copper heatsinks and I'm wondering how would the duty cycles compare with the two hosts? (bearing in mind that the c6 would have a copper heat-sink and the c2 would have a aluminum heat-sink) Would the c2 duty cycle be significantly better than the c6?

I greatly appreciate anyones suggestions and answers

 

[dubious speculation]

Anyone? :yabbem:

 

[IsaacT]

Well....both of them are anodized and therefore thermally inefficient.

The diameter of your heatsink for the C2 will be roughly 35mm based on the diameter of the host, subtracting for an educated guess on the width of the walls. The diameter of the C6 will be roughly 20mm....in fact, exactly 20mm as I have one sitting in front of me right now. I know the length of the C6 heatsink but not of the C2. For this I will assume they are the same length, though it is safe to say the C2 will be longer.

C2 Heatsink
Diameter: ~35mm
Thickness: 11mm
Length: Unknown(20mm for example sake)
Volume: 16.59cm^3
Density of Aluminum: 2.6988g/cm^3
Weight of Heatsink: 40grams

C6 Heatsink
Diameter: 20mm
Thickness: 5mm
Length: 20mm
Volume: 4.02cm^3
Density of copper: 8.92g/cm^3
Weight of heatsink: ~40grams

So they are both roughly the same weight in this calculation. However, bear in mind that if you take into account the actual length of a C2 heatsink, which should be more than 20mm, you might get up to twice the weight for the C2. The C2 will probably be better for you.

 

[dubious speculation]

thanks wannaburnstuff

i think i'll go with the c2 host, since i'm driving this build at 1.8 amps what would the approximate duty cycle be between the two hosts?

a bit unrelated to this thread but i've also read a fair bit on the m140 diodes and there doesn't seem to be a definite datasheet for the maximum amperage, most say the maximum is 1.8amps but many have pushed them beyond that, Blord sells his blue steel set to 1.9 amps, so what is the maximum SAFE amperage that will give a good life and ensures it doesnt LED sooner than expected?

cheers, will

 

[IsaacT]

I would stick to 1.8A if I were you. As far as duty cycle, a C6 is very limiting...30-60 seconds on, 60 seconds off. With the C2, maybe 50% longer or more? And at 1.8A you can expect about 2W if you use a G lens. Otherwise 1.6W or so.

 

[dubious speculation]

I would stick to 1.8A if I were you. As far as duty cycle, a C6 is very limiting...30-60 seconds on, 60 seconds off. With the C2, maybe 50% longer or more? And at 1.8A you can expect about 2W if you use a G lens. Otherwise 1.6W or so.

thankyou, so i know that 1.8 amps is the maximum safe amperage but will that ensure a long life for the diode as opposed to say 1.7 or 1.6 amps, sorry for the endless amount of questions, i just dont want to spend so much money on my first build and then for it to die like a month later

cheers, will :beer:

 

[IsaacT]

1.8A should allow your build to last many many hours. Remember diodes are often rated for 5000 hours. Even overdriving to 1.8A, your M140 should have a good long life. Just dont abuse it with a ridiculous duty cycle.

 

[dubious speculation]

1.8A should allow your build to last many many hours. Remember diodes are often rated for 5000 hours. Even overdriving to 1.8A, your M140 should have a good long life. Just dont abuse it with a ridiculous duty cycle.

thanks so much mate :beer: you've turned all my worries into nothing thanks so much for your advice on everything and thanks for taking the time to help me out, greatly appreciated payday is very soon :tinfoil: cant wait!!!

cheers, will :beer:

 

[Pi R Squared]

I have a M140 in a C6 with a copper heat sink driven at 1.5A this one:
http://laserpointerforums.com/f65/assembled-m140-c6-pic-heavy-83543.html
and I have run it as long as a minute or so twice before and it got really hot, it starts getting warm at about 15 seconds so I keep it to about 20 - 25 seconds max. These are both small hosts so don't expect a very long duty cycle. According to data from DTR at the bottom of this page:
https://sites.google.com/site/dtrlpf/home/diodes/445-m140-didoes
an M140 can reach 2w at 1.5A and can go well above 2w at 1.8A if you use a G2 lens. One more thing worth mentioning is the batteries, you may want to consider getting the extension tube so you can use two 18650, if you use two 16340 or cr123 it puts quite a strain on those batteries, they aren't made to put out that high of current for very long so get more than one pair, mine are mostly discharged after only a few minutes of use. Whatever you decide will work OK I am just saying don't expect too much for duty cycle or battery life.

Alan

 

[dubious speculation]

I have a M140 in a C6 with a copper heat sink driven at 1.5A this one:
http://laserpointerforums.com/f65/assembled-m140-c6-pic-heavy-83543.html
and I have run it as long as a minute or so twice before and it got really hot, it starts getting warm at about 15 seconds so I keep it to about 20 - 25 seconds max. These are both small hosts so don't expect a very long duty cycle. According to data from DTR at the bottom of this page:
https://sites.google.com/site/dtrlpf/home/diodes/445-m140-didoes
an M140 can reach 2w at 1.5A and can go well above 2w at 1.8A if you use a G2 lens. One more thing worth mentioning is the batteries, you may want to consider getting the extension tube so you can use two 18650, if you use two 16340 or cr123 it puts quite a strain on those batteries, they aren't made to put out that high of current for very long so get more than one pair, mine are mostly discharged after only a few minutes of use. Whatever you decide will work OK I am just saying don't expect too much for duty cycle or battery life.

Alan

thanks Pi yeah i knew about DTR's datasheet but i rarely see anyones builds at 1.5amps with 2w output, how long exactly do the batteries last in your c6 build? it would be more preferable although more expensive to have a host that fits two 18650's, i wouldve expected better for a copper heatsink, BTW nice build, I checked it out a while ago and its very imformative

cheers, will :beer:

 

[Pi R Squared]

thanks Pi yeah i knew about DTR's datasheet but i rarely see anyones builds at 1.5amps with 2w output, how long exactly do the batteries last in your c6 build? it would be more preferable although more expensive to have a host that fits two 18650's, i wouldve expected better for a copper heatsink, BTW nice build, I checked it out a while ago and its very imformative

cheers, will :beer:

Thanks Will, I don't know for sure because I haven't timed it but I would estimate that after only about 5 - 6 minutes of use there is a power drop in the laser although still incredibly bright and at that point I take out the batteries and put them in the charger and it takes about 2 hours to charge them indicating they are mostly discharged at that time, if they are only a little discharged they recharge all the way in only a few minutes, but these aren't high quality batteries either though, you would do better if you buy the most expensive batteries.

Alan

 

[dubious speculation]

Thanks Pi, I might pick up the battery extension tube from survival lasers I should invest in some quality AW batteries as well

Will keep you guys updated on how it goes

Cheers, will :beer: