Would You Believe a 180mW Blu-Ray?

GooeyGus said:

I've done it as accurately as possible. I know heat is still probably a factor, but I did it with the laser as far away from the sensor as I could get it, with all of the light still on the sensor head. I also made sure that the needle fell back to zero, with the laser still in place, to help eliminate any possibility that heat was adding to the reading. This still isn't as accurate as it could be, but I think its the closest I'm going to be able to get.

Click to expand...

Yeah, i remember how you did it. It's also how i tried to do it, but i didn't get the same results.. You got 32% more, Kage on the previous page got 23% more. I got pretty much any number when i changed the distance. Even up to 50% more! But i don't believe that.

Climbak said his proffesor got 100% more without plastic optics! But that's with a funny meter, attenuators and whatnot.


Anyway, you didn't answer my question... Would you rip the 6x diode in it's heatsink out of the writer, and ship it to me, so i wouldn't have to pay a fortune in custom fees and taxes? :

IgorT said:

[quote author=GooeyGus link=1214100163/60#62 date=1214718711]I've done it as accurately as possible. I know heat is still probably a factor, but I did it with the laser as far away from the sensor as I could get it, with all of the light still on the sensor head. I also made sure that the needle fell back to zero, with the laser still in place, to help eliminate any possibility that heat was adding to the reading. This still isn't as accurate as it could be, but I think its the closest I'm going to be able to get.

Click to expand...

Yeah, i remember how you did it. It's also how i tried to do it, but i didn't get the same results.. You got 32% more, Kage on the previous page got 23% more. I got pretty much any number when i changed the distance. Even up to 50% more! But i don't believe that.

Climbak said his proffesor got 100% more without plastic optics! But that's with a funny meter, attenuators and whatnot.


Anyway, you didn't answer my question... Would you rip the 6x diode in it's heatsink out of the writer, and ship it to me, so i wouldn't have to pay a fortune in custom fees and taxes?  :[/quote]

Of course! It would be my pleasure. Will you let me keep the red diode to play with if I pay all the shipping?  

You meant to say express shipping, right?

Actually, i don't have a single red diode.. I have given them all away.. And as far as i know, the red in a 6x is the same as the diode in a dilda.. Which again, i gave away.. :-[

I was talking to Phenol about it, and he is guessing it's like a canned open can.


P.S. Dave, did you see how quickly he jumped on it? He really is of the devil! Next he's gonna ask me to sign a contract in blood.. He already want's me to sign my red away.. :

Oh, about my freak diode.. There is one thing i forgot about before..

When i was making group pictures, the freak was set to the same current as all the other lasers i made (125mA) and doing 120mW.. But while i was trying to put them in formation, mine rolled off, and dropped to the floor from around 1.2m.

I got very scared, but it worked after that, so i forgot about it completelly. I only just remembered it now.

Theoretically, it's possible, that it could have contributed somewhat to it's demise.. On the other hand, maybe it didn't.


I read about another one dying at 195mA, but the rest would seem to die at >200mA, so looks like the power is not the only variation between them..

Another thing, that may have killed it was it's amazingly high optical output. I think i read something about that once, but i didn't quite understand it. But if i read it correctly, it's possible, that a diode that would put out less power could survive the same current better.


The other diode i set to a high current of 179mA is still doing fine, but as i said it's a weak one, so it only does 125mW...

I am making another >150mW right now..

Oh my god!!  


I finally put together a second high powered blu ray. I used a diode, that showed a slightly lower power than the freak diode, during the 109mA test.. I also used a lower current, than with the freak diode. "Only" 178mA.. The freak was at 187mA.


This second diode is putting out 178mW after a plastic lens!!!    

I can't believe it! I was so sad, when i lost the most efficient diode i thought i had.. But this one does more power with less current! (during the 109mA test it did "only" 95mW, while the freak did 98mW)

It's at the same current as the weak diode, which is doing only 124mW.


I used a more massive host with a slightly larger heatsink, so it won't heat up as much. I REALLY hope this one makes it! I was expecting 160mW at most..


It could have something to do with the lens tho.. I noticed, that if i take out one plastic lens, and put in another, the power can vary by 5%...

Check this out....


These diodes are amazing!

IgorT said:

Check this out....


These diodes are amazing!

Click to expand...

Very Nice, Igor. These diodes continue to be a crap shoot. Some very good, some less good. Oh Well. I think that taking the chance is worth it. 180mW on a humid night is amazing.

Peace,
dave

I can attest to the humidity being awesome. I was right off the beach in San Diego over the weekend and took full advantage of the high humidity and whatever power my PHR is putting out. I think the operative word is "amazing".

IgorT said:

You meant to say express shipping, right?

Actually, i don't have a single red diode.. I have given them all away.. And as far as i know, the red in a 6x is the same as the diode in a dilda.. Which again, i gave away..  :-[

I was talking to Phenol about it, and he is guessing it's like a canned open can.


P.S. Dave, did you see how quickly he jumped on it? He really is of the devil! Next he's gonna ask me to sign a contract in blood.. He already want's me to sign my red away..  :

Click to expand...

I will expect the contract in blood to be in my mailbox no later than a week from tomorrow. Then your 6x diode will be shipped ;D

The red diodes are pretty neat and they do look just like the dilda diode. I just end up killing them anyway so its probably better if you had it ;D I just want more people to experience the 6x sexiness!!!

climbak said:

I can attest to the humidity being awesome. I was right off the beach in San Diego over the weekend and took full advantage of the high humidity and whatever power my PHR is putting out. I think the operative word is "amazing".

Click to expand...

Now just imagine living in washington... we practically have gills its so humid here ;D

Well, i was talking to Phenol about this, and he confirmed, that it's not the current, but optical output, that kills them. That's why my first freak diode died at a lower current, than yours, Dave... The power after a plastic lens was close to what you're getting after a Meredith..

But since my second freak was putting out even more power - same after plastics, as yours after a Meredith - it might have been even more endangered.


I lowered the current to 168mA.. Now it's "only" doing 171mW. I was actually expecting less. I really don't want this one to die. Maybe i should lower it to 160mW?  

But i don't want to.. It's so pretty! I really hope the 20mA less will make it live longer, than the first freak, even tho the power is almost the same..
But i guess the killing point will not be the only variation in these. Maybe it'll make it! I just hope it lives long enough for me to put a custom lens in..

IgorT said:

Maybe it'll make it! I just hope it lives long enough for me to put a custom lens in..

Click to expand...

I'll bury a frog for you (and it) tonight at midnight.

Peace,
dave

That might help..

In the meanwhile i will push the weaker one further.. Since the optical power is lower, it won't commit suicide untill the current is really to high for it. It's possible, that the lower powered ones could easily take more current.


EDIT: I set the weaker one to 191mA, and it's only doing 130mW.. I'll leave it on untill battery protection kicks in. See what happens.

So i left the weak diode, that did 130mW at 191mA on for almost an hour. Now the diode is dead.

Looks like this much current for so long is too much for them regardless of the optical power. No wonder the first one died. Now i'm glad i set the other freak lower. I hope the 20mA less will keep it alive even tho the power is still 170mW.

IgorT said:

So i left the weak diode, that did 130mW at 191mA on for almost an hour. Now the diode is dead.

Looks like this much current for so long is too much for them regardless of the optical power. No wonder the first one died. Now i'm glad i set the other freak lower. I hope the 20mA less will keep it alive even tho the power is still 170mW.

Click to expand...

I know that you don't have nearly enough variables in this experiment yet. I want to add another. Voltage.

I decided it was silly to have all these parts sitting on my desk. I decided to build the lasers even if they won't sell. They don't spoil, right?

Anyway, I built some dual-head units. The idea (which worked) was to make the heads of the hosts/lasers modular and interchangeable on the body. Everything worked fine. However, since one of the pair's heads is a burning red laser, I decided to limit the batteries. The hosts have the three AAA carriage in them. I set them up with a dummy in one slot and powered them with two 10440's (7.2V). When I started testing them, the blu-rays were NOT giving me the output I was expecting. I have the old style Rkcstr drivers in them, so 7.2V should be fine.

I put a third 10440 in the carriage of the blu-ray (10.8V). The output climbed to what I was expecting. So at 177mA input with 7.2V I was getting 90mW. With the same driver, lens, and diode, at 10.8V input I am getting 150mW! These have the aiXiz acrylic lens with the backs cut out.

I had one of the blu-ray heads die a strange death (weird patterning to the light and then darkness. I must have hurt it) so I had to wire up a different one. I decided to check the output with different voltages. I ran my variable power source through a new style Rkcstr driver set at 180mA.

7.5V = 90mW
9V = 150mW
12V = 200mW

I also observed what Hemlock Mike did. As the diode heated up, the output would climb. I left it on for awhile at 9V. After it had become warm to the touch, the output started climbing. I turned it off at 210mW. After it cooled, it went back to 150mW

So there you have it. Y'all know I'm not knowledgeable about this electronics stuff. Here is the data. Have fun

Peace,
dave

Actually, it's not like that.. You can't have the same current and a lower voltage. It's physically impossible.

7.2V is not enough for a rkcstr driver to regulate the current for a blu ray diode. It needs 2.25-2.5V on top of what the diode needs. And the diode needs up to 5.7V at high currents, and a little less as it heats up.

If you don't give it enough voltage, the current is not what you set it to, as the driver drops out of regulation. And the power drops with the current, which drops with the voltage.

When the driver is in regulation, the voltage on the diode is whatever is required for the set current to flow through it - the driver regulates the current by adjusting the voltage on the diode - it always gives the diode just enough voltage to achieve the desired current, and then it adjusts this voltage, to keep current the same even as the internal resistance of the diode changes..

So if the voltage is too low, the current is too low as well.


I'm using a constant current boost driver. It needs 2.4-5.5V, and boosts the voltage to the exact value required for the current i set to flow through the diode. Since my driver works down to 2.4V, and protected Li-Ions shut down at 2.7V, the current on my diode never changes, untill it suddenly shuts down. The voltage also never changes, unless the driver changes it, to keep current the same as the diode heats up. All drivers do this. It's how they achieve constant current. The diode never sees the voltage going into the driver. It only gets what it needs from the driver.


For any current, there is only one voltage and the other way around (if the resistance is fixed). Diodes don't have a fixed resistance - it changes with heat. But that's why we use constant current drivers. As long as the driver is in regulation, the current will always be the same, and so would the voltage, only that the voltage changes with heat (the driver changes it).


The reason you got lower power with a lower voltage is because your driver was not regulating, and the current was lower, than you thought. With two li-ions, the full voltage is 8.4V, which is enough for a rkcstr and a PHR at the beginning, but as soon as the battery voltage drops to 7.7V, it's suddenly too little. So you may have measured the right current at the start, but by the time you got around to measuring the power, the current was already dropping.




To sum it all up: If your driver is regulating, the current is the only factor (together with heat of course). Voltage doesn't matter here, as long as it is what the driver needs. If it's less, the current is not what you think it is.


The power climbing HemlockMike observed was because he used a constant voltage source. With a constant current, the driver lowers the voltage, as the diode heats up. With constant voltage, the current climbs as the diode heats up (because the resistance decreases).

A constant current driver should not allow this to happen. The only way this could have happened is if it was set higher, than you thought, but didn't have enough voltage on top of what the diode needs, to keep the current constant. Then, as the diode heated up, and needed less and less voltage, the current went up, and closer to what you set it, so you noticed the power climbing.


If you want to make sure the driver is set correctly, you need to give it more than the minimum voltage it needs. To make sure, you would have to give it at least 6V (for the diode) + 2.5V (for the driver) = more than 8.5V.. And the power supply has to be capable of supplying the current without the voltage sagging.

If the power climbs with heat on a constant current driver, then something must be wrong at a certain point. On a constant current driver, the power should drop with heat. That's what keeps a diode safe.


If you were to measure the current WHILE this was going on, you would notice the current climbing. You also need to make sure, the supply voltage is above the minimum UNDER LOAD.