DIY Homemade laser diode driver

[gn0stik]

DDL, you say that you only used a 47uf because it's what was on the proto board you had. That's a very odd value cap for "just sitting" on the proto board. Radio shack doesn't even sell a 47uf 16v cap, individually, they do sometimes come in the packs though. They sell 47uf 32v, and 10uf 32v, but not specifically the one you said.

Also, I noticed you using a tantalum cap which are for use with ICs, does this matter?

If you had to pick one that rat shack sells, which one would it be? Better said, what would the ideal capacitor value be for this, application, seems everyone is using what you have used, but would a different farad value be ok? A different voltage value?

Thanks.

 

[rog8811]

I had too much time on my hands today...new picture of DDL circuit coming up....

Regards rog8811

 

[chido]

Nice schematic rog, but isn't the wire coming from the Vout of the LM317 supposed to be connected to the 2 Vin pins on the pot? And then the third Vout pin of the pot gets connected to the resistors. Correct me if I'm wrong, but I think you did it the opposite way. ;D

 

[goldfingerfif]

Very nice!!!!

 

[rog8811]

It doesn't matter which way you do it, I think as drawn it will reduce the resistance/increase the ma when the pot is turned clockwise. connect the way you say (and all the other drawings ) and it works in the opposite way.

Regards rog8811

 

[chido]

Ooooooooooooohhhhhhhhh!!!!! You learn something new every day. ;D

 

[drlava]

great drawing, that should really help some people
However, You should double check your LM317 pinout connections.

 

[rog8811]

You should double check your LM317 pinout connections

I am 99.99999% sure that is correct , see attached.....

regards rog8811

 

[gn0stik]

His pinout on the 317 is exactly correct. Instead of a jumper being used, he's showing it as it is logically. The adj is the pos, all the way, out, and the pot and resisters are providing the reference voltage from the out pin.

Make no mistake, although power is supplied by the Vout, the circuit's output as a whole is taken from Adj.

It's actually the best drawing I've seen thus far. Excellent work Rog.

 

[ndrew2505]

i bought some parts to make a driver with and since i found mostly smd/smt stuff i thought id share the mouser part #'s with every 1. the top # is the mouser # and the price for each peice is beside it. im not sure the pot will work b/c its a 1/4w but if some1 could verify...???

660-RK73B2ELTD3R9J 0.050
KOA Speer 1210 SMD T
1/2watts 3.9ohms 5%

583-FM4001 0.230
Rectron Rectifiers -
Vr/50V Io/1A T/R

81-PVG3A101C01R00 0.670
Murata Trimmer Poten
100ohms

595-LM317LIPK 0.540
Texas Instruments Re
3Pin 100mA Adj Vltg

5985-AVS35V47-F 0.370
CDE SMD Aluminum Ele
35V 47uF

 

[gn0stik]

OK, I just pulled a diode from sony cdrw (since my ones from stonetek never came), and now I'm kinda tripping out. It's got a small bit of silicon board attached to the back of it still because I don't really want to desolder it because of the heat. Problem is, two of the pins are soldered together right out of the cdrw. must be the photo and laser pins, right? The other one has to be ground correct?

Never run across this yet.

Rich

 

[ndrew2505]

lol i just got done doing the same thing with a slim ps2 laser. i usually use a 15w iron so if you move fast you shouldnt heat it up to much. not sure why the pins are soldered together tho...

 

[Gazoo]

OK, I just pulled a diode from sony cdrw (since my ones from stonetek never came), and now I'm kinda tripping out. It's got a small bit of silicon board attached to the back of it still because I don't really want to desolder it because of the heat. Problem is, two of the pins are soldered together right out of the cdrw. must be the photo and laser pins, right? The other one has to be ground correct?

Never run across this yet.

Rich

It doesn't contain a red diode...it is infrared...be very careful.

 

[Gazoo]

i bought some parts to make a driver with and since i found mostly smd/smt stuff i thought id share the mouser part #'s with every 1. the top # is the mouser # and the price for each peice is beside it. im not sure the pot will work b/c its a 1/4w but if some1 could verify...???

660-RK73B2ELTD3R9J 0.050
KOA Speer 1210 SMD T
1/2watts 3.9ohms 5%

583-FM4001 0.230
Rectron Rectifiers -
Vr/50V Io/1A T/R

81-PVG3A101C01R00 0.670
Murata Trimmer Poten
100ohms

595-LM317LIPK 0.540
Texas Instruments Re
3Pin 100mA Adj Vltg

5985-AVS35V47-F 0.370
CDE SMD Aluminum Ele
35V 47uF

The parts will be good to use for a blu-ray. The 317 you ordered is only good for 100ma's.

 

[ndrew2505]

thanks for that again gazoo. i guess i wasnt paying attention like i thought i was.... : (walks away whistling..)

Mouser #: 863-LM317MBDTG
Mfr. #: LM317MBDTG
Desc.: Linear Regulators- General Purpose 500mA ADJ 1.2-37V Positive
RoHS: RoHS Compliant By Exemption

or

Mouser #: 863-LM317MDTG
Mfr. #: LM317MDTG
Desc.: Linear Regulators- General Purpose 500mA ADJ 1.2-37V Positive
RoHS: RoHS Compliant By Exemption

 

[rkcstr]

OK, I just pulled a diode from sony cdrw (since my ones from stonetek never came), and now I'm kinda tripping out. It's got a small bit of silicon board attached to the back of it still because I don't really want to desolder it because of the heat. Problem is, two of the pins are soldered together right out of the cdrw. must be the photo and laser pins, right? The other one has to be ground correct?

Never run across this yet.

Rich

My method for removing boards from LDs:
1. hold the diode or whatever the diode is in with some locking pliers or clamp.
2. Use some tweezers to grab hold of the board only
3. Get a nice blob of solder on the iron
4. Put that blob across all the pins of the diode.
5. The board should pull right off as soon as the blob melts across the pins.

This should be done while the diode is mounted in a housing of some sort, ie before you remove it from what it's in, to minimize the possiblity of heat damage. Usually the pins are only heated for a second or two with my 12W pencil iron. If you don't have a low power iron, as long as you're quick, there should be no worry of damage.