GGW-H20L 6x Sled GB!!! THE EPIC GB THREAD LAWL!!!

[IgorT]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

Well, after the initial testing, i put my first 4x diode on a "lifetime tester". It's been cycling ever since.

The circuit turns the laser on for a minute and off for a minute, to simulate the power-up stresses, while a simple counter counts the number of times it detects the beam. This way i can multiply the number of counts with the duration of each cycle, to get the total on time. It is set up in a way that if the diode goes LED, the sensor won't detect it, and will stop counting. I measure it every so often, to check for degradation.


At the moment it's been through about 30 hours total on time.. It started out at 164.7mW (@150mA), on Saturday there was a small power drop which i attributed to temperature (wishful thinking), yesterday it was at 157mW, today it's at 154.9mW... Compared to other 4x tests, this is still a lot for 150mA, but the power is obviously dropping. I tested with an AR coated glass lens, to exclude the acrylic lens as a factor, but there the power is now at 190mW, while it started out at 202mW.

So it's quite a considerable power drop. This is somewhat consistent with a high efficiency PHR at the same power, altho a PHR would be dead by now...

 

[thesk8nmidget]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

Well, after the initial testing, i put my first 4x diode on a "lifetime tester". It's been cycling ever since.

The circuit turns the laser on for a minute and off for a minute, to simulate the power-up stresses, while a simple counter counts the number of times it detects the beam. This way i can multiply the number of counts with the duration of each cycle, to get the total on time. It is set up in a way that if the diode goes LED, the sensor won't detect it, and will stop counting. I measure it every so often, to check for degradation.


At the moment it's been through about 30 hours total on time.. It started out at 164.7mW, on saturday, there was a small power drop which i attributed to temperature (wishful thinking), yesterday it was at 157mW, today it's at 154.9mW... Compared to other 4x tests, this is still a lot for 150mA, but the power is obviously dropping. I tested with an AR coated glass lens, to exclude the acrylic lens as a factor, but there the power is now at 190mW, while it started out at 202mW.

So it's quite a considerable power drop. This is somewhat consistent with a high efficiency PHR at the same power, altho a PHR would be dead by now...

this test is at 150ma correct?

 

[IgorT]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

Yeah. I was expecting 140mW at 150mA, but got 164mW. A lower efficiency diode might do better at the same current, since it would put out less power..

If it was on continuously, it may drop slower, due to no power-up stresses. But that's not really usefull info in most cases, so i decided to use the cycler i had from another experiment.


At this point i think, that the diode is better than PHRs. Maybe it could actually survive 130mW. But it's really hard to say. I can't afford to kill as many as with PHRs...

 

[thesk8nmidget]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

well i didnt really get time to make another but i will be putting it at 150ma as well and will be setting it up for cw.

 

[IgorT]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

Try aiming at 140mW. If the power is higher than expected, reduce the current a little. Current doesn't matter nearly as much as power.

Mine is at 153mW at the moment.. I'm surprised it didn't die yet. The largest drop i saw on a PHR at this power was 6mW and then poof. But at ~100mW they can sometimes just drop and drop in power, without dying. Theoretically, 150mW for the 4x could be a similar strain as 100mW for a PHR.

I will just let this one run for as long as it works.

I'll try 140mW next time. That's still 170mW with a glass lens. Unless of course the wavelength is shorter, in which case the actual power is higher.

 

[thesk8nmidget]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

alright i will set at 150ma and then once on the meter i will turn it up or down til i get it at 140mw

 

[carulli]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

how would someone who doesn't have a power meter tell what current to run his at
ya think 150ma?

 

[IgorT]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

Also, at this point, i am fairly certain, that even a 6x (GGW) can not take 200mA forever.. And when i say forever, i mean at least a few hundred hours.

It's a miracle, that it survived my level of use at this current for so long. But i can definitelly see some degradation now, that i raised the current even further. There is no doubt about it now. The idea was to speed up degradation to confirm it, but now that i have nothing to replace it with, i almost regret it. I could set it back to it's original current to slow down the dying, but at this point it would probably only do 180mW there, while it started out at 193mW.

But it definitelly is the toughest blu ray diode ever. It's struggling on even at 219mA. Had i left it at 198mA, it would probably keep on going for quite some time. I just did a measurement with a plastic lens, and it was 209mW. When i first set it to this current it was 213mW, and it degraded a bit before that at 198mA.

 

[IgorT]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

how would someone who doesn't have a power meter tell what current to run his at
ya think 150ma?

I know what you mean. That is always a problem. But even if you do have a meter, the problem remains, because shorter wavelength diodes waste more in plastics, so if they measure the same after a plastic lens, the actual power is higher. And it's that, that the diode has to be capable of handling (+ reflections).

Otherwise, there is always a certain risk regardless of the power, and at levels to which we are overdriving them, the question is how long you want it to last.

At this point my test diode lived long enough, that it would last you one month, if you used it one hour per day. If you used it 20 minutes a day, it would last three months. And it's still working. But Kage lost one at a lower power in barelly any time at all. So it varies from diode to diode, what they can take. I will test another one as soon as i can, see what happens.... Judging from the graphs, the next one should have a slightly lower power..

 

[IgorT]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

The 4x is at 154-155mW today... And i'm at almost 60 hours...  :-?

This diode is definitelly better than any PHR i've seen so far. It does degrade, but slowly, and it's still keeping on. When i put a random PHR through the same testing i get anything between 3-20 hours, but not much more. So i think by now it is safe to say that the 4x is a bit better. Let's see how long it lasts. As it is, it would already survive months of heavy use, even in my hands..

I really hope that i didn't just condemn the best of the bunch to death... But it's possible that for this particular one 150mA is similar as 125mA for the average PHR. It is approximatelly at the same level above the first kink, since the first kink is slightly higher with these....

 

[jayrob]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

Thanks for your work on these Igor... keep this excellent information coming!
Jay

 

[mophead]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

The drives these sleds come from; what current, voltage and power are they set at OEM?

Me personally, i'd rather have 30mw less power for a several magnitude gain in life.

I don't want to run it at the bare minimum to get it to lase, but i don't think the OE manufacturer does either.

I guess my question is where is the middle ground; time/power vs current/power?

 

[amkdeath]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

ok so I spoke with the supplier regarding the GGW-H20L drives. There is good news and bad news:

Good News:

His supplier has them ready to sell to him, and then to me


Bad News:

He can only buy them 2000 at a time and then sell to me in smaller quantities, and he is not willing to take the risk of buying 2000, then only selling like 200.

 

[danq]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

ok so I spoke with the supplier regarding the GGW-H20L drives. There is good news and bad news:

Good News:

His supplier has them ready to sell to him, and then to me


Bad News:

He can only buy them 2000 at a time and then sell to me in smaller quantities, and he is not willing to take the risk of buying 2000, then only selling like 200.

well... at what price?
I could swing my share of that - at, say, $2 per :

 

[chopper]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

Hmmmm....  How much would 2k diodes cost? ...probably ~$80k...can't justify that cost for the hobby  

...but it would be so awesome to have 2000 diodes!!

 

[amkdeath]

Re: 6x Blu-ray SLEDS GB! THEY ARE GOING FAST!

it would come out to USD 55 each.