Help with blown 405nm diode using rkcstr driver

[tabarin]

Hi all, I just got a complete 150mw 405nm diode + rkcstr kit using an aixiz case, wired it up and got it working using a 9v battery as input and it ran great up to 170 mA (max pot setting). I was reading you get more power out of a 12v setup so I attached a 12v supply and turned the pot up to max power and the whole thing blew out and the rkcstr got really hot. I'm not sure what broke, if it was just the diode or the rkcstr driver or both? I'm trying to figure out what I need to reorder.

Thanks all for the help.

 

[MarioMaster]

Your problem was in using a 9 volt battery to set the current. 9 volt batteries are pretty much useless in the laser world due to their low current capacity. The voltage in the battery probably sagged so much from the load that you set the driver much higher than you should have - so when you hooked it up to a beefier power supply it sent far more current into the diode than you wanted and the diode went poof.

Both may have broken but probably just the diode.

So next time, use a better power source than a 9v for setting the current, to ensure the driver is regulating properly.

Hope that helps

 

[tabarin]

thanks MarioMaster

 

[tabarin]

I read through the rkcstr manual in detail and I attached the dummy resistance load they describe (I used a potentiometer at the lowest setting, which gave 3.2 Ohms) and the driver still works fine! I ordered another one anyway but I'm happy to know it still works.

I discovered the output very quickly goes from 180 mA to almost 500 mA toward the end of the rkcstr pot adjustment range so I think that answers how my 150 mW diode blew so quickly on the 12v bench supply (which could supply adequate current like MarioMaster was explaining).

 

[sandmasterful]

holy crap thank god I found this the samething happend to me!!!!