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PHR 803T with Aixiz Acrillyc Lens not burning, why?

C

CollegeLaserAmateur

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Hey my ~100mW PHR 803T diode isn't burning anything. And don't even say i'm not focusing the beam because i am... It's focused for close up, then i eye-ball where to put the paper or match depending on dot size... I don't want to keep the LD on for more than a minute so i don't possibly hurt it.

I'm using an LM317T driver with a 10 ohm resistor, so at the most i'm at 120mA and i'm using new batteries (4 AA).

Here's what i think i'm doing wrong: i'm using a copper wire to connect everything, so it's not loose wire, it holds form pretty well, and it is either 18 or 20 gauge copper wire. Since it is bigger than what i see most people use for their own builds, i was wondering if the resistivity of the wire is making the power drop off so much? I would buy a glass lens from LarryDFW but this is my first build and it doesn't have to be perfect, my next build, hopefully green, will probably have a LarryDFW lense on it...

Another question, what is the purpose of the focusing ring? i lost mine because i didn't know it's purpose, thus not caring too much about it... i still have the spring (which i guess is used with it), i realize it goes in between the diode and the focusable lens, but which side does it go on? closer to the diode? and what does it do? (i didn't get a chance to play with it before i lost it)
 





It is either not getting 120mA, or you are not getting it focused, or you are not holding it steady, or the lens is dirty, or someone has divided by zero and the laws of physics have broken down . . . . . . . . .

NNNNIIIIIIKOOOOOOOOOO!!!!!!!!!!! :tsk:

Peace,
dave
 
Haha, no we didn't break the laws of physics, i'm hoping. Well my thought of the wire causing more resistance than planned is proven wrong. I found information online and found that if i'm using a foot of copper 18 gauge wire, it is creating .02 ohms of resistance. BUT, i have another hypothesis: Would my poor soldering skills cause bad connectivity and produce bad current flow???
 
CollegeLaserAmateur said:
Haha, no we didn't break the laws of physics, i'm hoping. Well my thought of the wire causing more resistance than planned is proven wrong. I found information online and found that if i'm using a foot of copper 18 gauge wire, it is creating .02 ohms of resistance. BUT, i have another hypothesis: Would my poor soldering skills cause bad connectivity and produce bad current flow???
Click to expand...

Usually solder joints are either good or bad (or work and then quit). It may be possible that some soldering problem prevents your driver from actually putting out 120mA.

Check all of the ideas I listed above:
current - How do you know it is 120mA?
focus - A focused violet is a VERY small, pinpoint dot
steady hold - Use something beside your hand to hold the laser
dirty lens - Self explanatory
division by zero - Blame Niko (I always do)

In addition to the above (if your laser is really dim) you may have blown the diode and you really only have a 5mW LED now. :(

Peace,
dave
 
My Laser is on youtube here:

YouTube - My First laser build

(i can't figure out how to embed the video for some reason, don't understand the computer coding language)

It's a pretty bright laser, and if anything, i'm using more solder than necessary, but all my joints are holding up well. Here's another thing i just remembered... I was wondering if the LM317T's 3 pins were coated with any material that i should have filed off before soldering?
 
CollegeLaserAmateur;

You need to borrow a multimeter and check the current .

It should be measured between the battery and the negative wire or frame.

If it measures 120ma, then the focus is the issue.

LarryDFW
 
I was just about to ask that question about a voltmeter/ampmeter, but i decided to go looking around the forum first... Thanks LarryDFW! when i make a good enough laser i'll buy one of your amazing lenses, the fit right into an Aixiz module, right? does the lens come with the parts that go around it (the ridged metal part you hold onto to twist and the part that screws into the module?
 
What's the voltage drop with this LM317T driver? Is a 6V power supply enough to power the violet?

Peace,
dave
 
daguin said:
What's the voltage drop with this LM317T driver? Is a 6V power supply enough to power the violet?
Click to expand...

Found my problem... i don't have a multimeter yet, but i used rog8811's website to put together the driver, and i didn't scroll down to see the suggested input power, he says 9v should work... but 6v allows the battery to work, i think the LM317 is outputting at or above 3V... What about the focus ring? what's its purpose, along with the spring...???
 
I have same driver with same 10ohm resistor and it burns matches, using a 200ma rechargeable 8.4v battery (same as 9 v alcaline). The spring is to keep the lens nut tight, as it's got quite a bit of play.
 
CollegeLaserAmateur said:
Found my problem... i don't have a multimeter yet, but i used rog8811's website to put together the driver, and i didn't scroll down to see the suggested input power, he says 9v should work... but 6v allows the battery to work, i think the LM317 is outputting at or above 3V... What about the focus ring? what's its purpose, along with the spring...???
Click to expand...

6v is not enough to run DDL lm317 driver at 120ma. Personally I find that 8.55v is the minimum threshold for powering my 110ma PHR. Anything below and the current begins to rapidly drop off.

As for the focusing ring, it is used to change the focus of your laser. As I understand the spring is just there to prevent the lens from wobbling around (correct me if I'm wrong). The pressure the spring places on the lens assembly effectively keeps it from moving around too much.
 
Yup, its the input voltage, 4 aa cells will not cut it. If you actually measured current, you'd find it would be much lower than the aimed for 120 mA. Try a 9V battery to make sure, its very likely to solve the problem right away.
 
I didn't have a 9V battery on hand at the time so i modified it a bit to use 6 AA batteries... It works just fine... Thanks for all the help guys!

 
Last edited:
SPECTRAL 532, I love your AVATAR !!!!! Very Colorful, & Laser Appropriate......... rob
 
Thanks phoenix77. Your own avatar isn't too shabby either. Are the images in your avatar pictures of lasers you own?
 
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