flogged
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OK.. I was fortunate enough to have a friend pick me up another xbox hd today. So here's try #2. Long story short, got things lasing @30mA and it seems stable, though not as bright as my last one.
...Two wasted drives. Sigh.
Diode extraction. Used the xacto knife to pop the diode out from the back. An anonymous 5mm can, with the lettering '"SB016L481" across the side. Go figure.
First light, metering up to 30mA this time. I wired three 10 ohm resistors in series to increase the resistance. During my first attempt (using one 10 ohm with pot turned all the way down) the laser came to life at slightly over 40mA, which may have damaged it. This time it came to life consuming 25mA. I carefully nudged it up to 30mA. It occurs to me that each mA for these violet lasers is about twice as significant as a red because of the voltage difference. A 10 mA difference in current is likely quite significant for these low powered violets.
Closeup of the innards. The Meredith housing is getting a little rough. This the third diode it's housed, and I had to rip the last one out and scrape all the glue out before gluing the latest one in.
Lasing...
Unfortunately there's some bad spray around these diodes. It's a rectangle of violet, either end tapering to a yellow color. The diode spot itself can be focused well using the Meredith housing, spray aside. The spray appears to be some sort of reflection/fluourescence from the diode itself. Image below is from my first attempt, after it died. The diode spot became dim and milky, and the spray got brighter.
I'm sorely tempted to turn the power up a few more mA... but once bitten twice shy.
It's little wonder not many people make these. These diodes are very fragile, and there's a lot of room to f*ck things up making even a simple pointer. But it's a rush when you get it working.
...Two wasted drives. Sigh.
Diode extraction. Used the xacto knife to pop the diode out from the back. An anonymous 5mm can, with the lettering '"SB016L481" across the side. Go figure.
First light, metering up to 30mA this time. I wired three 10 ohm resistors in series to increase the resistance. During my first attempt (using one 10 ohm with pot turned all the way down) the laser came to life at slightly over 40mA, which may have damaged it. This time it came to life consuming 25mA. I carefully nudged it up to 30mA. It occurs to me that each mA for these violet lasers is about twice as significant as a red because of the voltage difference. A 10 mA difference in current is likely quite significant for these low powered violets.
Closeup of the innards. The Meredith housing is getting a little rough. This the third diode it's housed, and I had to rip the last one out and scrape all the glue out before gluing the latest one in.
Lasing...
Unfortunately there's some bad spray around these diodes. It's a rectangle of violet, either end tapering to a yellow color. The diode spot itself can be focused well using the Meredith housing, spray aside. The spray appears to be some sort of reflection/fluourescence from the diode itself. Image below is from my first attempt, after it died. The diode spot became dim and milky, and the spray got brighter.
I'm sorely tempted to turn the power up a few more mA... but once bitten twice shy.
It's little wonder not many people make these. These diodes are very fragile, and there's a lot of room to f*ck things up making even a simple pointer. But it's a rush when you get it working.
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