Leaderboard

I guess this is the same one that is also on Elektrotanya. Sadly it does not have any circuit diagrams, only (rather poor quality) PCB layouts. Probably -30V. But the VFD should work with -17V as well, only somewhat dimmer. I am not sure that this SM is 100% consistent, because parts numbering seems different on the PCB layouts and in the parts list. Nevertheless, if the VFD driver IC is what we see in the SM, then its datasheet talks about -35V (actually anything down to -40V).

Finally, my homebrew laser power meter is put together. It cost $3 worth of surface mount components, a used disc sacrificed for the shell, a piece of pcb, and some other stuff I found in the back of my drawer. Initially I tested it with my digital multimeter hooked on those test terminals, but then I found this neat little five-digit Volt-meter I bought some time ago on ebay, I think it was five bucks or so with free shipping from China. Without much fine tuning, I popped this little probe into all the decks I had at hand, and measured the laser power. From the mV readings and the nominal laser power values I calculated the mV-to-mW multipliers, and I took the average of a unit I trusted the most, a 940. Using this sole multiplier as the "calibration", I recalculated the measured mW figures and compared to the factory recommended range. Most of the other units were nicely within specification, but this 530 in question, that immediately popped out, being near 40% below the necessary values, i.e., 0,55 mW and 4,32 mW versus 0,9 mW and 7,0 mW respectively. Now, it might be that easy, but before changing anything, I want to check the IOP, to see, whether that meets the specs, and set the measured value for further adjustments. For this I will need that rig connecting to the drive, currently waiting for the special connector to arrive. So much for now, I will update the thread as I progress. Some photos attached below, just for fun.