DIY Homemade laser diode driver

[.3lite]

If you want so simplity, you should use LM350 (3A max at output) or LM338 (5A max at output), otherwise build some more advance driver on operation amplifier.

For example something simply like this one, I did it myself (provide from 0mA to 2,5A, 100% lineal current regulation by pot)

 

[jaycey]

Hi guys, ive got my driver sorted for a PHR and have now been experimenting for a LPC diode.
Problem I am having is I am getting alot of heat bulding up quickly on the LM317, I am using a 7.4V LiPo (8.3V at full charge) 100ohm pot and a 1 ohm resistor to get 400mv tested across the 1ohm resistor with the 4 inline 4001 diode test load.

Would a lower voltage bettery make a significant difference or should I try something different? (heat sink on the LM317?)

Cheers

 

[drakesword]

Alright so i started the digikey thing and this is what I have so far.

TIP127FS-ND TRANS PNP DARL -100V -5A TO-220
TL431ACLPRAGOSCT-ND IC REFERENCE PROG 2.5V TO92
P3C3103-ND POT 10K OHM 9MM VERT NO BUSHING
LM358ANFS-ND IC OPAMP DUAL 0-70DEG C 8-DIP
P5165-ND CAP 100UF 35V ALUM LYTIC RADIAL
P823-ND 0.47UF 50V MINI ALUM ELECT (KA)
PPC1.0KW-3JCT-ND RES 1.0K OHM METAL FILM 3W


Can someone double check my research to make sure im not being stupid.

Also what is 1R and all of the components (i guess diodes) on the upper left of the board?

Many thanks

 

[millirad]

Here is a combination that has really been working perfectly for me. Build the standard DDL driver per the diagram and use these components. 0.12 ohm resistor (NTE part# 1W012), 100 ohm trimpot (NTE 20 turn cerment), 47uF 50V cap, 1n4001 diode, LM317T regulator, 2 cr123 3V batteries in series for 6V. Dial in any current you need. ;-)

Hi guys, ive got my driver sorted for a PHR and have now been experimenting for a LPC diode.
Problem I am having is I am getting alot of heat bulding up quickly on the LM317, I am using a 7.4V LiPo (8.3V at full charge) 100ohm pot and a 1 ohm resistor to get 400mv tested across the 1ohm resistor with the 4 inline 4001 diode test load.

Would a lower voltage bettery make a significant difference or should I try something different? (heat sink on the LM317?)

Cheers

 

[jaycey]

Cheers , ile give it a go.

 

[Rad86N]

yo.. i just ordered the stuff to make the driver and i wonder if i can use the power of my pc USB connector.. its +5V which could be enough, but i have no experience with this driver so i'll be glad if you can answer me
greetings from Czech

 

[rog8811]

you can use 5v input....as long as your laser diode only needs 2v to run
...but you already know that as you looked it all up using search.....
("psst!" click the link to my website and go to the driver page, all you need to know in one place).

Regards rog8811

 

[Rad86N]

thanks, but i tried it anyway.. got 2.33V and max 125mA?! of current.. I used this scheme from your site, rog8811.. i forgot to buy the 4AA battery case.. so thats why im improvising with the USB. .. burns the el.tape easily and can light matches.. i dont have any balloons currently at home although i usually got plenty of them at this time of a year :-D
if you have any other suggestions for me, please post a message, im czeching this site a lot these days..

take care..... of your eyes. later

 

[oldscooliron]

I'm using a red diode from a dvd burner 22x & just finished building "rog8811" driver on his website. I'm now going to build the load tester (4 diodes & 1 ohm resister) but is the (1 ohm resister) a 1/2w or 1w? Also when you load test the driver does the LD have to be hooked up or does the load tester go between the pos & neg where the LD gets connected & you load test it that way? Can someone explain after the above questions are answered as to how & what numbers your looking for & basically how I know my LD will be safe?

I built "rog881" driver using 7.2v here: It can be done - Laser driver

I don't consider any question dumb but when operating a laser like this do you need to wear the laser glasses if not shining off reflective surfaces?

 

[rog8811]

A 1/2 watt resistor is fine for most applications

does the load tester go between the pos & neg where the LD gets connected & you load test it that way?

Yes, like this..... (picture shows it set up for IR LD but it is the same for all driver/laser diode combinations, just use the correct number of diodes.

Alternate test point is for checking out a driver with the LD already attached so ignore it for the moment

Regards rog8811

 

[oldscooliron]

thank you rog8811 for explainning that & also providing a picture!

What numbers will I be looking for on the DVM to make sure my LD will be safe?

 

[oldscooliron]

Oh I forgot to ask when you use a laser like this can it burn other colored thing other than black? And do you need to use laser glasses?

 

[rog8811]

What numbers will I be looking for on the DVM to make sure my LD will be safe?

As I have only built 16X reds I couldn't say, use the search button the info is here!

Oh I forgot to ask when you use a laser like this can it burn other colored thing other than black? And do you need to use laser glasses?

Yes and yes

Regards rog8811

 

[oldscooliron]

thank you again!

 

[Rad86N]

i cant find any laser power calculator... how can i measure the laser diode power? can i use the equation "P = U * I" ? U is voltage measured in paralel with the diode and I is the current flowing in series with the diode. It seems too easy to be true to me. because that would mean that my 16x burner laser pointer powered by usb - 2.33V and 125mA would get about 290mW..

 

[oldscooliron]

Ok I'm lost here I know where the DVM leads go on the load tester but what am I looking for? Max. on the pot means max resistance Min. means the least resistance but looking at the numbers on the DVM is one thing but how do you know what you LD can handle? Or say I just want to run a 20x LD at 200ma?

I'm using "rog881" driver using 7.2v with 2 - 10 ohm resistors, 25-Ohm 3-Watt Rheostat, open can LD 20x in the circuit.

I tried searching but I don't see anything saying x amount of voltage for 20x LD ect.

What laser glasses could you recommend?