How bright should a Blue Ray look next to 5mW red?

[IgorT]

Re: How bright should a Blue Ray look next to 5mW

These two were rolling around the customs office for nearly a month, because there was no invoice in the package and our customs officials get SEVERELY ANAL, when there is no invoice..

When i got there, with an invoice, the woman took them out in her hand and asked me what they were.
She actually took them out of the bags! I almost went nuts.

I wonder how many times they did this before they actually released them to me and if they were throwing them around or what.


I just don't get it. How can it suddenly loose half it's brightness with current regulation at 39mA?!?
I was looking towards the beam from a few meters, admiring it, and suddenly it just dimmed.



What a horrible feeling...

 

[wooooooolazer]

Re: How bright should a Blue Ray look next to 5mW

Man, whats going on.. you do have a cap soldered on to it right, to keep from voltage spikes?

...lazer... ;D ;D ;D

 

[Gazoo]

Re: How bright should a Blue Ray look next to 5mW

I am sorry about this. :'( The second one should not have suddenly crapped out running at less than 40ma's...no way. Are you sure there isn't something wrong with your power supply? I know you know your stuff, but you need to find out what went wrong.

 

[chimo]

Re: How bright should a Blue Ray look next to 5mW

Sorry to hear this as well. Sounds like COD. http://www.repairfaq.org/sam/laserdio.htm#dioldl

 

[desslok]

Re: How bright should a Blue Ray look next to 5mW

I'm wondering if something is wrong with your power supply or something. It's not adding up. Can you put a 1 ohm diode inline and test witha multimeter just to verify? And you have the cap and diode soldered to the LD to make sure the load is the same as everyone else is talking about?

 

[IgorT]

Re: How bright should a Blue Ray look next to 5mW

I have the cap directly on the diode inside the AixiZ module, and i was using a different power supply - the LM317 - on the second one.

Just to be safe, i tested it on two other LDs and an array of LEDs. Then i put on the first (bad) BR.
After pushing the first one till it made a nice spot i just repositioned it, and it shut down.

Now it's lasing treshold is above 150mA. It still makes a beam at around 170 - 180mA, but i think it's getting weaker by the moment. And it gets very hot.


Then i put the other one on, and this one seemed to be perfect! I fell in love with it immediatelly. The beam was wonderfull. The spot was MUCH brighter than the 5mW red at 39mA.


Then i was admiring the beam in some smoke, and it just dimmed. I immediatelly went back to it and checked the readings and they didn't change, but i shut it down just in case.

After that i put the current down to the minimum before powering it up, and again slowly worked up, and now it wants 84mA to be approx as bright as the 5mW red.



Oh, i was powering the 317 from a fresh 9V battery, with a multimeter between the battery and the circuit for the current, and another multimeter on the LD for the voltage.

I never disconnected the LDs from their capacitors, and i shorted the capacitors, before soldering them on.


I just don't get it.

 

[IgorT]

Re: How bright should a Blue Ray look next to 5mW

Well, the second one is completelly gone now.. Well it's an expensive LED.

The first one still makes a beam, if i puff smoke directly towards it. But it takes 220mA at 6V. It gets so hot it's hard to hold it. I can see the voltage dropping, as the LM317 compensates to keep the current constant as the LD heats up and loses resistance.


I still don't get it. I took two different approaches. I mounted the first one on a cap and on my lab PSU with current limiting. But that one was weird from the start anyway.

For the second one i used the LM317. Slowly worked the current up to 35 then 42 and back to 39mA.
It was wonderfull, and then it just stopped being wonderfull.


I just took the LD off, and tested the LM317 circuit again. It works flawlessly. I'm gonna go build another powerfull red burner now, just to feel at least a little bit better.



I would like to try another Blue Ray, but it might be better to wait till the burners become cheaper.

I wonder how long that will take...

 

[wooooooolazer]

Re: How bright should a Blue Ray look next to 5mW

Wait, how were you measure the current? Where you just putting the meter in curent mode and measure the circuit in paralel? Most of the time that can cause it to die.

...lazer... ;D ;D ;D

 

[IgorT]

Re: How bright should a Blue Ray look next to 5mW

Wait, how were you measure the current? Where you just putting the meter in curent mode and measure the circuit in paralel? Most of the time that can cause it to die.

I don't understand.. Are you asking if i put the multimeter in current measuring mode and put it across the circuit output, shorting it?!?

I don't think that would kill the diode, as the current would just go through the meter instead of the LD. That's what the protection diode does, in order to save the LD, if you reverse the polarity by accident. Even the LM317 would survive, since it has built in protection.


But no, i build electronics for work, so i wouldn't do that.


I had one multimeter for voltage, in parallel across the circuit's output, and another multimeter in series for current.

I also know i'm not suposed to put the meter in series between the LD and the circuit, because that would mean disconnecting and reconnecting the LD, which can sometimes result in "bad things", especially if the circuit is powered and the LD gets disconnected temporarily.. (Or is this what you meant, when you said "in parallel"?)

So for current, i just put one meter between the battery and the circuit, because the current there will be the same as the one through the LD, since there is only one path for it.


It's the safest place in my oppinion, for measuring the current, other than using a 1 Ohm resistor in series with the LD and measuring the voltage drop on it.

 

[IgorT]

Re: How bright should a Blue Ray look next to 5mW

Anyway, i was so friggin carefull, that i still don't understand what happened.

On the other hand, while these two (now dead) babies were in the customs office, the officials were taking them out of the boxes and even the bags, looking at them, trying to figure out what they are, because there was no invoice in the package.


When i told this to Daedal, he said he is going to seal the next two in ESD packaging, and plaster them with so many ESD warnings, that it should get the point across.


Our customs are so incredibly anal, that even when there is an invoice, they go online to check if the prices are correct. And they have to classify everything as a certain number, in their holly book of tarrif classifications.


Now that i know what they classified them as and what kind of invoices they like, i will write that invoice and send it to Daedal, so that he can include it with the next two Blue Rays.

Yes, i decided to get two more.

They're addictive... I have a problem...

 

[Gazoo]

Re: How bright should a Blue Ray look next to 5mW

I don't recall but you did harvest these from the sleds....right? Customs would have had to almost stomp on them to do any damage.

 

[IgorT]

Re: How bright should a Blue Ray look next to 5mW

I don't recall but you did harvest these from the sleds....right? Customs would have had to almost stomp on them to do any damage.

You are correct.. I did harvest them myself.

So do you think it is impossible for ESD to hurt them while in the sled? I'm just trying to figure out what happened...


Still, when i mentioned to Daedal, that the woman took it out of the plastic, when she asked me, what they were, he said he would throw a fit, if they did this to him..

That's why he'll plaster the next two in so many ESD labels, they will have to be posessed by the devil, to even think about opening them..

 

[desslok]

Re: How bright should a Blue Ray look next to 5mW

Or not...

Now it needs 85mA to get approx the same brightness or maybe even slightly less. It also get's a little warm.
On the other hand, the first one is still a laser. It needs approx 170mA and is slightly less visible than the second one after the misterious disaster.
So now i have two blue ray lasers, both heavily overdriven, and both not as bright as they would be if they were ok..

Maybe you have 2 overpowered focused LEDs? Because when they are LEDs they can still be focused and look like weird blu-ray laser dot(minus the beam which you normally can't see anyways), but they heat up more than when they are lasing at low current....

 

[IgorT]

Re: How bright should a Blue Ray look next to 5mW

Maybe you have 2 overpowered focused LEDs?  Because when they are LEDs they can still be focused and look like  weird blu-ray laser dot(minus the beam which you normally can't see anyways), but they heat up more than when they are lasing at low current....

Something like that, yes..

The second one, that seemed to be good, died completelly, while the second one that was weird from the start, still makes an actuall beam at 220mA.

The beam is much weaker, than it should have been at 35mA if it was ok.

But i still managed to take a pic of it..

 

[IgorT]

Re: How bright should a Blue Ray look next to 5mW

The picture is over exposed, and my hands were shaking a little.


The red is the 5mW that comes in AixiZ modules..
The blue one is running at 220mA and somewhere above 6V.

It was getting extreemely hot and the output was visually dropping.
But the weird thing is, i can still get it to do that, only not for very long.

And while the beams look like they have the same intensity, the blue is actually much weaker than the red one. Before this happened, it was like 4x brighter than the red one at only 38mA.



BTW: The above picture is one of a group of pics i made to proove to someone, that holograms are not mid air three dimensional volumetric projections, created by crossing laser beams, to create "air-pixels".

When some people read "lasers are used in holography" they think, this means projecting things in mid air and even in daylight. Go figure..



I blame science fiction and those companies, that say they offer 3D holograms, when they really offer just a normal 2D projection on a fine mist, or a version of the "Pepper's Ghost" trick...