One more of FIRST BLU RAY threads, advices aprecciated

[Eudaimonium]

Alright, haven't been on this forum quite a while so i'd like to appologise for any questions already asked and so on, just i don't have he nerve to find the search button in here.

Today my first PHR 803t sled arrived, after a long wait and expectations, since i never even saw a bluray laser in my life, (did read a lot of it though) and since i payed a sum of 10 $ for it, wich is a lot of money to me, i do not have the funds to learn from mistakes.

Now, before i take it outta envelope, i beg of everyone with experience here to properly address most common mistakes and problems found in extracting, mounting, and firing up the diode.
I plan on using ddl driver, 90 mA (don't wanna take any chances), aixiz w/ acrylic lens.
No flashlight hosts for now, since most probably the power source is gonna be 9V Battery,
it ain't gonna fit anywhere.

So again everything i should look out for and take special care would be appreciated.
And yea, if anyone says 'don't break diode glass window' i'mm'a crack some heads open.

I do have a lot of expirience with reddies, assembled quite a few, i know my electronics, soldering skillz and so on.
Just advices on something that differs from red lasers.

Thanx all in advance!

 

[daguin]

If you can build a red, you can build a violet. The only real difference is the voltage and current. You should be familiar with setting those from your red builds

Peace,
dave

 

[iskor12]

^^^^^I second what Dave said. 100% spot on Dave^^^^^^

 

[Eudaimonium]

OK all you saying it should be ok as long as i'm carefull and not rushing things.
Great.
Just one more thing.
What wass that talk somewhere about soldering case pin to one of the other pins? what do i get with that?

 

[Asherz]

If you can build a red you can build a violet Just remember to have the current around 90-110ma (Double check this with a test load of 6 diodes and a 1ohm resistor.)

Also remember to check you short the capacitors on the driver if you've plugged it into battery's to test the current, just put a screw driver across it for a while but you probably know this :0

As for soldering the case pin, as far as I know you should just leave that alone as it's not really needed, just make sure you know the pin configuration correctly.

Don't quote me on the not needing the ground pin though

GL

 

[Eudaimonium]

If you can build a red you can build a violet Just remember to have the current around 90-110ma (Double check this with a test load of 6 diodes and a 1ohm resistor.)

Also remember to check you short the capacitors on the driver if you've plugged it into battery's to test the current, just put a screw driver across it for a while but you probably know this :0

As for soldering the case pin, as far as I know you should just leave that alone as it's not really needed, just make sure you know the pin configuration correctly.

Don't quote me on the not needing the ground pin though

GL

Alright let's use double checking

* positive
* not used (case)
* negative

Right?

WTF can't get spaces there... stars are D shaped, or right poining arrow.

 

[bryce007]

Alright let's use double checking

* positive
* not used (case)
* negative

Right?

WTF can't get spaces there... stars are D shaped, or right poining arrow.

Since it isn't going into a host, you could do it that way. However I'd solder the case pin to the negative pin anyway, so you don't have a floating pin.

Here's a link to the pinouts for various diodes:

http://laserpointerforums.com/f42/meta-topic-pinout-performance-actual-ld-26417.html

 

[Eudaimonium]

OK guys i'm currently working on ddl driver, hooked up everything, dummy load is 6x diodes and 1 ohm resistor, and something ain't right.
I am not using trim resistor but i got a collection of low tens (10 ohms 20 ohms and 30 ohms)
I put 10 ohms for the first try. Hooked up 9 V batt ( it vas 8.7 V acctually was used some time ago) and got very nice 7V round to the dummy load. But measuring milivolts across 1 ohm res in dummy load is weird: it shows no more than 15 mV ! How can that be? tried replacing 9V batt with AC DC adaptor and set it to 9V (it gives more like 12 V ) and there is
11 V across the diode but no more than 17 mV on ohm resistor.
How is it possible that i cannot get more than 17 mA on my 'diode' ??
LM regulator was (i'm pretty sure) not damaged.

How come??

 

[Eudaimonium]

OK guys disregard last post new problem has arrisen.
I have replaced 4 of the diodes prom dummy load with new ones cuz old ones were not them selves lately. Now i get a very nice current with 33 ohms resistor , 106 mA.
Problem is that now the voltage is frozen. Cannot get more than 4.7 V on the diode.

What the hell is happening here?

 

[Tabish]

OK guys disregard last post new problem has arrisen.
I have replaced 4 of the diodes prom dummy load with new ones cuz old ones were not them selves lately. Now i get a very nice current with 33 ohms resistor , 106 mA.
Problem is that now the voltage is frozen. Cannot get more than 4.7 V on the diode.

What the hell is happening here?

The diodes are dropping the voltage.

 

[HIMNL9]

This is normal, being a constant current driver.

They limit the current through the load, limiting the voltage that they give out, and you have "only" 4,7V on the diodes, cause that is the voltage dropped from the diodes (the 1 ohm resistor is not influencing the output voltage too much, in this case).

Trying to explain it a bit more clearly, with my bad english ..... the diodes are in the dummy load just for emulate the voltage needed from the laser diode for work ..... red emulation requires only 4 diodes, cause they work at minor voltage of blu-ray ones (the "working voltage" of laser diodes is also indicated as FV, or Forward Voltage, in some posts) ..... the BR laser diodes emulation uses 6 or 7 diodes, cause they usually have a FV of 5 V, or around 5V (5,7 or over, for 6X - 8X diodes) ..... it's just a way for give to the driver a load that have an electrical characteristic the more similar to the one of a true laser diode, so, the regulation of the current is made in working conditions that are the more similar to the final ones.

As example, in a constant current driver, you can also just put the resistor at the output, and read the mV directly on it, without the diodes, but in this case, when you take away the resistor and substitute it with the LD, the working conditions of the driver changes dramatically, and you cannot be sure that it works in the same way ..... just as example, i suppose that you know, that any linear regulator have a "dropout", that is the quantity of voltage that the driver "lost" in its working, and this dropout also affect the final working characteristics of the driver ..... so, if you have a Vin of 6V (just examples), and a dropout of 2V in the driver, you can work good only with diodes that don't require more than 4V, for work.

Using a simple resistor at the output, still left you regulate the correct current that you want, but if after this you connect a LD with a FV of 4,5V, you can never made it work at the current that you have regulated, cause the voltage is insufficent ..... if instead, when you regulate the current, you use a load that cause the same voltage drop of the FV of the laser diode, you can see that the current is not regulated in the correct way, and increase the Vin til it work correctly ..... this is the main reason for which n the dummy loads we use diodes, so they acts as more as the possible like "real" laser diodes.

So, don't care about what voltage you read at the diodes or at the output of the driver, you only need to care about the voltage that you read at the sides of the resistor, cause only this is the important value, for set the current

 

[Eudaimonium]

Well first 2/3 of the post is all i already know however, the rest was helpful.
Thank you. So i have my current, (i have lowered it to 80 mA , no chances taken) i am now going to hook up my real violet diode to test circuit (on the project board).
I'm so anxious to see it in person. If everything is ok, I'm going to start planning the PCB.

Oh yeah, BTW , + rep for you.

 

[Eudaimonium]

Yep, made PCB this morning, tested it, assembled everything in a small project box.
Holy crap! The most beautifull laser definetly. Works excelent. Funny how you eyes can't focus that kind of light so you have to look double the distance away to see the dot nicely. How cool.
Laser is operating at 79 to 83 mA (as i said, no chances taken), held it on for like 30 seconds, module still remained dead cold. Smokes some black stuff and can light matches. Still havent managed to light one cuz all i have some cheap matches that appear laserproof.
It smokes the hell outta her but the bitch won't burst into flames. In dimmed light conditions very nice visible beam.

As Dave had well put it, ain't much different from building a reddie.
Except all the fun afterwards.

 

[Eudaimonium]

Ok guys I'm'a post some pictures for the first time on this forum
The build is not eye candy host , however i could not wait to get it assembled so i can make those module caps glows

Pictures by Eudaimonium - Photobucket

Taken with 8 mpix, about 5 MB each.

I have to save some money for some 10440 batteries so i can make it a nice flashlight host, an' ting

Enjoy!