Hi doctor
, i received today the other drive, again thanks.
By the way, i have done some tests on the survived one, and also repeated them on the one arrived today, and discovered one thing that can explain (maybe) the threads that says that these drivers kills diodes .....
BAD SWITCHES
I usually use dummy load and DMM for set the current, but the day i was doing it on the driver, i had all the DMM in use, so just connected the oscilloscope to the resistor of the dummy load ..... and have seen that, in some conditions, the "ramp start" of the regulator, become fooled from "scratching connections" of the wires (sorry, don't know how to explain it better, my bad english strikes again
)
I mean, if you don't use a good switch, or also just use bare wires kept on the battery with hands, the output of the driver, instead the usual "ramp" (it's fast, but it's still a ramp) at startup, made a, how can call it, glitch, spike, that can go
from 1,5 times to 2,5 times the presetted current, also if the duration is usually around 50 to 100 microseconds (at least, with the driver presetted at 200mA, i got spikes that was from 300 to 550 mV, on the 1 ohm resistor, that means 300 to 550 mA of current) ..... this happens both connecting and disconnecting the power supply, but
only occasionally, and
ONLY using very bad switches (that generates lots of bounces) or "scratching" the wires on the battery poles (mean, intentionally making insecure / spiked contacts)
As far as i have seen, it happens usually just one or two times each 10 or 15, but being LD's sensitive as they are, and maybe in some mounts, being
"just a little bit pushed high in current" ..... after all, if you use it for a 200 mA diode, and time by time get "spikes" of 550 mA, the diode can also resist, if cold and not frequently used, but if already overheated from use, in critical conditions and frequently turned on and off, it can become damaged from repeated spikes like these, i think.
Anyway, as i said, my tests was getting these spikes only around 10% of the times, so i'm not sure if the real cause of these dead diodes can really be this one ..... will try in the next days some more exaustive tests, after i build something for not have to stay myself pushing the button all the times (it was already difficult to find a weak button, here, had to intentionally ruin one, LOL) ..... maybe an old relay with half-burned contacts, drived from a 555 ..... and, if i get something better than this webcam, trying to shoot some pics to the scope screen (nothing to do with the webcam, sorry)
But hey, if the problem is really this one, solution can just be using good quality switches (and, maybe, an rc series with 100nF and 22 ohm in parallel to the input, too, just for the safety
)