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

[IgorT]

Hi all!


I just got my first two Blue Rays from Daedals group buy.

I put one in an AixiZ module and started at 35mA, and it glowed, but it didn't make a spot on the wall.
I raised it to 45mA and it made a hardly visible spot.
Next was 56mA (4.3V) and now the spot was at least visible, but a 5mW red that comes in those AixiZ modules looks much brighter.

From some pics around here, i got the impression, that they made quite a bright spot. I had to turn the lights off to see it as anything more, than a tiny blue dot. It wouldn't even work as a laser pointer during the day...


I haven't tried the other one yet, but is this normal?

How bright should a Blue Ray appear, compared to a 5mW red?


Thanks!

 

[desslok]

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

i got mine from psxboy.com, but same model. Anyways, I had mine lasing at 25 mA, and it was pretty dim, bumped up the pot to 36 and it was bright, and when focused it is pretty bright, but I am having trouble focusing mine, as all i had left to use is a lens froma butchered aixiz where the inside hole is chopped up.

 

[JECS]

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

4.3 v? i see a lot of people running these 4.5-5v, otherwise it wont really light for them. but you would still want to keep it around the 20-25ma range i think

 

[IgorT]

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

4.3 v?  i see a lot of people running these 4.5-5v, otherwise it wont really light for them. but you would still want to keep it around the 20-25ma range i think

For every current, there is only one voltage possible. (if you ignore changes in resistance from the heat).
You can't have the same voltage, but different currents at that voltage.


When i set my power supply to a certain voltage and limit the current, it automatically drops the voltage, so that the current is what i set it. Basically, the power supply gives the LD just enough voltage, to reach the current you want.

If i were to set the voltage to 30V, but still limited the current to 54mA, the PSU would automatically drop the voltage to 4.3V.
The LM317 circuit works the same way. It regulates the current by regulating the voltage so the current is constant.

Did anyone actually measure 4.5V at the BR diode? What was the current at that voltage?



Anyway it's physically impossible for me to raise the voltage and drop the current at the same time. So that's definatelly not the problem.
I'm just scared of running it at 54mA, since many people reported it dying at that current..

But it's very dim even at 54mA.

Is there something wrong with my BR diode or is there something wrong with my expectations?

 

[desslok]

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

[quote author=IgorT link=1201807931/0#3 date=1201812999Anyway it's physically impossible for me to raise the voltage and drop the current at the same time. So that's definatelly not the problem.
I'm just scared of running it at 54mA, since many people reported it dying at that current..

But it's very dim even at 54mA.

Is there something wrong with my BR diode or is there something wrong with my expectations?[/quote]

Yeah the way the 317 is set you won't be able to change voltage. However if your battery sags below 7.5 or 8, you may have issues when the 317 drops out. If you are using a 9v battery that shouldn't be the case, but may want to meter it just in case? i didn't meter mine's voltage, so not sure. All I know is mine was pretty dim at 25 mA, and very bright at ~36. So something is definitely wrong, maybe you turned into an LED? How are you measuring current for your readings you stated? Have you tried removing the diode and using your diode check on your meter?

 

[chimo]

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

See the last pic of the first post in this thread:

http://www.laserpointerforums.com/forums/YaBB.pl?num=1196123930/all-0

 

[IgorT]

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

I tried to make a comparison photo of the Blue Ray and the 5mW red side to side.
For some strange reason, in this picture they look almost the same brightness.

In reality, the blue dot is much smaller and dimmer. To me it looks only half as bright as the red one, or even less..


I need more light for a better comparison.

 

[IgorT]

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

See the last pic of the first post in this thread:

Thanks chimo!!

That's exactly what i was looking for!

At first i thought there wasn't a comparison to a 5mW red untill i scrolled to the right..
That's exactly what mine looks like side to side.


But what does this mean.. Should i continue at 53mA or should i go lower? Because at 45 it's hardly even visible...



BTW: Chimo, did you get a chance to measure your BR's output power? What current were you using in that pic?


Thanks!

 

[IgorT]

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

Yeah the way the 317 is set you won't be able to change voltage.  However if your battery sags below 7.5 or 8, you may have issues when the 317 drops out.  If you are using a 9v battery that shouldn't be the case, but may want to meter it just in case?  i didn't meter mine's voltage, so not sure.  All I know is mine was pretty dim at 25 mA, and very bright at ~36.  So something is definitely wrong, maybe you turned into an LED?  How are you measuring current for your readings you stated? Have you tried removing the diode and using your diode check on your meter?

I'm not using the LM317 yet. I was using a Lab PSU i made, with the current limited and with a capacitor on the BR LD.

Otherwise i know all that. I work with electronics proffesionally. I'm just new to lasers. My only other laser project was a red DVD burner at 300mA. It's one powerfull laser.


This one is not a LED yet, because it does make a beam, if i create smoke and look towards it.

The beam looks very nice, but the beam from the 5mW AixiZ red is brighter.


The current and the voltage show up on my PSU, but i double check with a multimeter.


I may have expected too much, i don't know.. But i thought the spot would be much more visible.. I read people use them as pointers at presentations.. I don't think this one would do that..

I also read Gazoo lit a match at 53mA.. I don't think mine would do that, and i would expect it to have to be much brighter for that..


You said yours was very bright at 35mA. What does that mean? Would the spot be visible inside, during the day? How visible? Usefull as a pointer for a presentation?

 

[chimo]

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

That was probably at around 40mA. They should be very visible at 45mA.

Remember that there is a lot of neergy in the beam you don't detect with your eyes. Try the same comaprison on white paper (or something that will fluoresce) and you will notice that the Bluray output seems to increase.

[quote author=chimo link=1201807931/0#5 date=1201813703]See the last pic of the first post in this thread:

Thanks chimo!!

That's exactly what i was looking for!

At first i thought there wasn't a comparison to a 5mW red untill i scrolled to the right..
That's exactly what mine looks like side to side.


But what does this mean.. Should i continue at 53mA or should i go lower? Because at 45 it's hardly even visible...



BTW: Chimo, did you get a chance to measure your BR's output power? What current were you using in that pic?


Thanks![/quote]

 

[jake21]

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

if u want to sell it ill buy it

 

[Gazoo]

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

Hello Igor..nice to see you around..

I think something is wrong with your diode, or maybe that one has peculiar characteristics. It is very odd yours is only 4.3 volts with 56ma's. I am running mine with 38 ma's, and the voltage is 4.93 volts. It is very difficult for me to see the beam in total darkness looking towards it or away from it. But the dot seems at least as bright as a 5mw red.

I really don't know what to suggest. But since it doesn't seem to be working properly at 4.3 volts, try raising the current some more. If it goes "poof" at least you have another one to play with. I hope at least one of them works out. The color is simply awesome IMO. I took the lens off of mine last night and was shining it around the house. Very interesting...lol Good luck buddy.

 

[adgmeijin]

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

hey Igort here's one of my pic of my working Blu-ray, i shot it in the dark with a flash of a phone cam, my input was 9volts using DDL LD driver set to, 4.5-4.7volts @ 38mA-40mA, (i use 2 10ohm resistor to make it 5ohm),it really works well and bright I used it almost a month now in daily basis, nothing change, and when I change it with fresh battery it gives me even more brightness i never expect.

 

[Gazoo]

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

hey Igort here's one of my pic of my working Blu-ray, i shot it in the dark with a flash of a phone cam, my input was 9volts using DDL LD driver set to, 4.5-4.7volts @ 38mA-40mA, (i use 2 10ohm resistor to make it 5ohm),it really works well and bright I used it almost a month now in daily basis, nothing change, and when I change it with fresh battery it gives me even more brightness i never expect.

I hope you posted a typo...the resistor should be 33 ohms...not 5 ohms..

 

[IgorT]

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

Nice to see you too!

I think something is wrong with your diode, or maybe that one has peculiar characteristics. It is very odd yours is only 4.3 volts with 56ma's. I am running mine with 38 ma's, and the voltage is 4.93 volts. It is very difficult for me to see the beam in total darkness looking towards it or away from it. But the dot seems at least as bright as a 5mw red.

4.93V at 38mA.. Interesting. Something must be wrong with mine then.. Well, that's why i got two anyway..
I really hope i get luckier with the next one.

A while ago i saw someone mentioning he thought his BR was dead, untill he raised the current up to, i don't know, was it 60-70mA?
Could be mine is like that.. I don't know. But i can't find where this was said anymore...

I just completelly smoked up the room, and the 5mW from the AixiZ (which i only bought for the modules) made such a nice visible beam, i almost fell in love with it. But the BR.. Well, i could see the beam, but it was much MUCH dimmer.

I'll make some more pictures tomorow in daylight, so the difference in the brightness of the spot on the wall will be much more apparent.


If the spot would be as bright as the 5mW red, it would be great..

I really don't know what to suggest. But since it doesn't seem to be working properly at 4.3 volts, try raising the current some more. If it goes "poof" at least you have another one to play with. I hope at least one of them works out. The color is simply awesome IMO. I took the lens off of mine last night and was shining it around the house. Very interesting...lol Good luck buddy.

Wait. You can take the lense of yours, and it gives of enough light to illuminate the surroundings? I just tried this at 53mA.. Hardly anything..

First i'll try the other one, to see if there is any difference. If the other one should happen to be much brighter, i'll try to push this one, and if it goes poof, oh well..


Anyway, thanks for the advice! I need some encouragement at this point..

 

[IgorT]

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

I hope you posted a typo...the resistor should be 33 ohms...not 5 ohms..

BTW: What is the max current with 33 Ohm resistor?

Could it be, that he used the two 10 Ohm in series?