resistors?

[Forgottenalarm]

so i have been looking forever and definalty decided to build a ddl driver for my PHR-803T Blu-Ray coming in the mail. i found about 5 diff resistor combos with the same other parts and im getting very confused.
i was wondering if someone can clairify for my what is the best combos to use?

here are the parts list of what the diag described that i have:
9 volt battery
switch
100 ohm pot
LM317 volt reg
2- 10 ohm resistors??????????????????????
1n4001 diode
35V cap

 

[GooeyGus]

You choose resistors based on what you want your max current to be.

Use 1.25 (the voltage ref. value for the LM317) divided by your resistance to get max current. so 1.25 / 10ohm = .125A = 125mA so a 10ohm resistor will let you go no higher than 125mA.

7.5ohm worth of resistors will give you a 200mA max because 1.25 / 7.5 = .2A = 200mA

Hope that helped.


Oh yeah, two 10 ohm resistors gives you 5ohm total resistance if wired in parallel (like they usually are in the schematic) which will give you 1.25 / 5 = .25A = 250mA max current

 

[LarryDFW]

Forgottenalarm;

I use one 10 ohm resistor in my PHR builds with the #317 current reg.
That sets the current @ 125 ma.

The center terminal on the regulator is the output of the LM317.

Attached is a pictorial layout of the LM317 layout I modified for BluRay (125ma) from rog8811:

It has worked OK with no failures so far, in a good aluminum heat sink.

LarryDFW

 

[Forgottenalarm]

got it, thanks guys. ima solder her up at work today. hopefully my laser will be here soon. order my goggles this weekend.

 

[Forgottenalarm]

Re: driver testing

so my greeness is showing. i soldered up the driver. im only getting.20 volts difference with adjusting the pot. from 7.5x to 7.3x. i thought the pot controlled more of the voltage/ current then that?? im trying to find a suitable testing source. all i can find is a pr3 flashlight bulb which isnt doing anything and the only multimeter i could find only tests volts.

 

[rog8811]

The voltage won't change much it is the current you need to measure.
Make a test load with 6 diodes for the load and a 1ohm resistor as a shunt, measure the volts across the resistor with the meter set to mv and you get the current in ma.

Regards rog8811

 

[Forgottenalarm]

k great thanks. p.s. got my laser in the mail [smiley=2vrolijk_08.gif]

 

[Forgottenalarm]

tested about 21-123ma. so i went for it.  and it is the most vibrant color i have ever seen in my life. i turned up for the few seconds i had it on about 2 minutes apart as to not burn out the ld.

but yet this is only the begining.

i still need a glass lens and goggles.
create a labby host with fan and swap out the 10 ohm resistor to a 5 ohm while reworking the
pcb to a breadboard for better componant testing/learning as well as placemant.



shall we take bets to see how long the lens lasts?  :

 

[proud2deviate]

You don't need an IR filter. That's just for DPSS systems, like green, blue, and yellow. Violet laser diodes emit no IR light. For your glass lens, make sure that it's anti reflective coated for the proper wavelength. The Aixiz lens is not good for 405 nm.

Looks like you've got the rest pretty well figured out. Best of luck!

 

[Forgottenalarm]

yeah i found a little more info on that late last night.
good lookin out man!

i think im going to build a heatsink so i dont have to buy one.. i have some thermal compound at home. thats a little more saved up for the glass lens...

 

[milantheone]

i have also made a calculator for DDL driver, which should help you to calculate a value of two or three resistrors in parallel connection... plus you will get also a rough estimation of a mA.....

i hope this will help to someone

 

[Forgottenalarm]

it would help, but i dont have excell. thanks anyman.

 

[milantheone]

it would help, but i dont have excell. thanks anyman.

that sucks..
anyway, maybe it will help to someone else..  i should aslo post this calcurator to the original thread about DDL driver, but i am tooo lazy at the moment to seach it..  

 

[Forgottenalarm]

Here is my laser at about 130 ma.

found a descent size piece of aluminum and drilled it out, installed some thermal compount that i was using for my processor installation in my pc. now all i need is a 5 ohm resistor and i will remake the driver to support more heat. (IE. heat sink on the L317T, more space between componants, and a fresh pot.)

 

[LarryDFW]

Forgottenalarm;

The 130 ma you are operating at, is a good level, if you want to keep your BR diode operating.

By going to 5 ohms, you will go to 250 ma of current, which is too high for the optical mirrors of your diode.

A larger heatsink will not allow operation at that level.

I do know where you can get a good Hi-Power lens assembly

LarryDFW

 

[Forgottenalarm]

yeah i realized that a little later on. i have some feelers out now finding me some drives that are no good anymore- well to 99% of everyone else anyway. from there i will harvest more powerfull lasers to experiment with. if i ever scrape up enough cash i will just toss the phr in a host and whip it out for the nice foggy nights up in the woods in the country.

but on a side note, you ever shine one of those on hunter orange. its pretty looking.