Thx to all the guides from this forum, i managed to assemble my own DDL circuit on a breadboard and harvested my first dvd-rw LD .
Unfortunately, I couldnt figure out how to remove it from the mount, so now my LD is still stuck in this iron-material-like chamber.
On my first try, I had to turn my pot to the minimum setting to see any light at all. Is this supposed to happen? I measured the voltage accross the LD to be roughly 1.7+V before it started emitting light. And the amount I get is just a wee bit of unfocused light.
From what I understand from the LM317T datasheet, the chip in current regulator mode gives out roughly 1.25V/(R+Rpot). I measured that to be about 7ohms fixed, and my pot at 7ohms minimum gives a maximum current of ~90mA?
Does this mean my LD is dead, or is it working, but I just need to give it more juice?
Also, issit just me, or does the diode not fully discharge the capacitor? I read someone's suggestion to put a tiny resistor accross the capacitor to help completely discharge it. Is this necessary?
Things for me to do now:
Get a 1ohm resistor to help me measure current.
Try to remove the LD from the mount.
Get smaller resistors to put in series with the pot. (What is a good resistance value to try?)
Unfortunately, I couldnt figure out how to remove it from the mount, so now my LD is still stuck in this iron-material-like chamber.
On my first try, I had to turn my pot to the minimum setting to see any light at all. Is this supposed to happen? I measured the voltage accross the LD to be roughly 1.7+V before it started emitting light. And the amount I get is just a wee bit of unfocused light.
From what I understand from the LM317T datasheet, the chip in current regulator mode gives out roughly 1.25V/(R+Rpot). I measured that to be about 7ohms fixed, and my pot at 7ohms minimum gives a maximum current of ~90mA?
Does this mean my LD is dead, or is it working, but I just need to give it more juice?
Also, issit just me, or does the diode not fully discharge the capacitor? I read someone's suggestion to put a tiny resistor accross the capacitor to help completely discharge it. Is this necessary?
Things for me to do now:
Get a 1ohm resistor to help me measure current.
Try to remove the LD from the mount.
Get smaller resistors to put in series with the pot. (What is a good resistance value to try?)