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Old CD-DVD Burner






Gryphon

Gryphon

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The writing diode will be 780nm. Ive built a laser with a cd rewriter once before, i set it
conservatively at 100mA and it was enough to do the usual burning tricks when
properly focused (pop balloons, light matches, cut tape). It is a near infrared
wavelength and is very deceiving with its pale red light, dont underestimate how
much of it you cant see, just like any other infrared laser.
 
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hwang21

hwang21

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Hello Gryphon,

Thanks for the information. I've never taken apart a CD drive and built my own laser from it yet, so this could end up being just messing around... :whistle: and I have an 808nm laser so I am aware of the deceiving looks of IR lasers, but thanks for the reminder!
 
hwang21

hwang21

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Ok so I have successfully extracted the LD from the unit (aside from a bit of desoldering from the final ribbon cable). What voltage and current should I run the diode at? I have a 2x AA system at 3V but I know that there can be a runaway current issue. Can I still use this system for a few seconds to check that the diode actually works? Even at 780nm the dot should appear dim but still visible. Any ideas? Thanks!
 
Cyparagon

Cyparagon

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You need to drive them constant current like any other diode. If you want a "quick check," you can use 3V+ with a resistor. Something around 22-100Ω for 3V. The raw 3V from your cells WILL kill it instantly, because the forward voltage is somewhere around 2V.

I've only played with one once or twice, but I hear anything over 100mA is risky. It also depends on the "burner speed."
 
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hwang21

hwang21

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Burner speed is 48x read and write, 24x re-write. Thanks for the info!
 
hwang21

hwang21

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So I've finally pulled the diode out and de-soldered everything... so now it looks like a plain old 5.6mm red laser diode. However, using a 3V (2x AA) power source hooked to a 100 ohm resistor barely produces any dot (even with IR light there should be a (albeit) dim red dot). At 10 ohms, it's better but still nowhere near even 1mW of output power. So then... am I dealing with a (very) high current draw diode, or is this a half-fried diode or something?

EDIT: At 0 ohm resistance (internal resistance aside), I can get 1-2mW output but the laser diode heats up very quickly... any ideas?
 
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Cyparagon

Cyparagon

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If it wasn't dead before, it's certainly dead now. Did you put it on the power meter, or were you using your trichromatic ocular devices to estimate power?
 
hwang21

hwang21

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Power meter lol on any resistors the reading didn't change at all. At zero resistance the readings might've been just from the heat the diode was producing or something too
 
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