Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Testing DDl's circuit

rog8811

rog8811

0
Joined
Jul 24, 2007
Messages
2,749
Points
0
Thanks nvmextc! I said someone would confirm 6 diodes :)

@ caleb.... There is nothing wrong with using this driver with the blu ray, I just got lazy and used Rkcstr drives :)

Regards rog8811
 





rog8811

rog8811

0
Joined
Jul 24, 2007
Messages
2,749
Points
0
The LM317 will take up to 38v, if I remember correctly, the more volts you put in the better the heatsinking required for the regulator.

6 X 1.5 = 9v, red LD needs 3v, LM317 needs 3v which means that you have an overhead voltage of 3v.
That would work fine and the heat generated by the regulator would never get too high as you will be using the laser with a duty cycle to protect the LD anyway.

You could consider using 6 Ni-cads @ 1.2v each which gets you back to the ideal voltage.

Regards rog8811
 
D

Droyd

0
Joined
Sep 1, 2008
Messages
126
Points
0
and whats a good test load for a red LD?
i hav 2 1n4001, 1 green led and some 10ohm resistors
 
C

caleb

0
Joined
Nov 27, 2007
Messages
321
Points
0
how can i make this driver fixed.
i saw somewhere there was a formula but cant find it.

thanks.
 
A

ArRaY

0
Joined
Jul 18, 2008
Messages
281
Points
0
A good testload would be 4 of those diodes in series.

The formula was 1.25 / R = I in Amps.
 
C

caleb

0
Joined
Nov 27, 2007
Messages
321
Points
0
can you give me an example.

say i wanted 100ma

thanks

EDIT: i.e. 100ma to the diode.
 
D

Droyd

0
Joined
Sep 1, 2008
Messages
126
Points
0
something i noticed in my circuit is that if i put a 10ohm resistor it makes the current very low, like around 1mA
whats wrong>???????????? :eek:
 
D

Droyd

0
Joined
Sep 1, 2008
Messages
126
Points
0
i tried it without a resistor, and it works fine i measured 2.5 volts and 250~Ma
is that bad for laser diode?
 
rog8811

rog8811

0
Joined
Jul 24, 2007
Messages
2,749
Points
0
@ Droyd, Could you put up a photo or a drawing of what you have done? It will help with diagnosing the problem.

Regards rog8811
 
D

Droyd

0
Joined
Sep 1, 2008
Messages
126
Points
0
Picture of circuit with no resistor, it gives out 8 volts this is what I use for my LD
 

Attachments

  • DSCF0428.JPG
    DSCF0428.JPG
    2.8 MB · Views: 221
A

ArRaY

0
Joined
Jul 18, 2008
Messages
281
Points
0
Use paint.

You don´t really connected your LD without the resistor??? 8V is WAY to much for any diode....
 
You must log in or register to reply here.




Top