adjusting rkcstr driver for 300mW LOC

[5jf5]

Hey!
A month ago I built my first red laser. I saw somewhere I should adjust mym driver to 380mA and it worked fine but now I feel I want more power, and set it to 410-430mA. I feel like I'll break the diode if unsolder it a 2nd time! I'm wondering if I could just adjust the current while the diode is working...
Thanks!:wave:

 

[daguin]

It is always dangerous to adjust a diode while current is going to it. Sometime your hand slips or the electronics take a big jump and your diode is toast.

If you are willing to take the chance, then you would also need to be using a linear driver so you could monitor the current from the battery side. If you are using a boost or buck driver, then it is a total crap shoot

Peace.
dave

**EDIT** Opps! I just noticed in your subject line you mentioned that it was a Rkcstr (linear).

 

[5jf5]

Thanks but what do you mean by "monitor the current"?
I used a dummy load made out of 4 diodes and a 1 ohm resistor(which I measured using a multimeter and it ended up being a 2 ohms resistor..)

 

[chipdouglas]

as dave said it is a little risky to adjust current while diode is soldered. but i do it. if you are ok with the risk vs reward factor than do it. but you will need a digital multi meter and set it to the 2 amp setting and and move your red probe to the 2 amp socket. the red lead clamps to the diode + and the black to the diode -.

then you need to power your driver with the same voltage that is in your laser. turn on your meter, then turn on your laser. the laser wont lase but the meter shoud get you a reading. then super delicately adjust your pot.


michaell.

 

[5jf5]

Thank you all for your great answers!

 

[5jf5]

What if my dmm only has a 10 amps socket? I guess it's just better...

 

[chipdouglas]

it should be fine. but it also depends on the resolution of your display. for example if you display only reads in whole numbers with no decimals youre in trouble. if you have 3 decimal point resolution you should be fine.

michael.